diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/marker.c | 930 | ||||
| -rw-r--r-- | kernel/module.c | 18 | ||||
| -rw-r--r-- | kernel/sched.c | 444 | ||||
| -rw-r--r-- | kernel/sched_debug.c | 1 | ||||
| -rw-r--r-- | kernel/sched_fair.c | 414 | ||||
| -rw-r--r-- | kernel/sched_features.h | 122 | ||||
| -rw-r--r-- | kernel/sched_idletask.c | 4 | ||||
| -rw-r--r-- | kernel/sched_rt.c | 7 | ||||
| -rw-r--r-- | kernel/trace/trace_event_profile.c | 79 | ||||
| -rw-r--r-- | kernel/trace/trace_printk.c | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_syscalls.c | 97 |
12 files changed, 681 insertions, 1437 deletions
diff --git a/kernel/Makefile b/kernel/Makefile index 3d9c7e27e3f..7c9b0a58550 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -87,7 +87,6 @@ obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o -obj-$(CONFIG_MARKERS) += marker.o obj-$(CONFIG_TRACEPOINTS) += tracepoint.o obj-$(CONFIG_LATENCYTOP) += latencytop.o obj-$(CONFIG_FUNCTION_TRACER) += trace/ diff --git a/kernel/marker.c b/kernel/marker.c deleted file mode 100644 index ea54f264786..00000000000 --- a/kernel/marker.c +++ /dev/null @@ -1,930 +0,0 @@ -/* - * Copyright (C) 2007 Mathieu Desnoyers - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - */ -#include <linux/module.h> -#include <linux/mutex.h> -#include <linux/types.h> -#include <linux/jhash.h> -#include <linux/list.h> -#include <linux/rcupdate.h> -#include <linux/marker.h> -#include <linux/err.h> -#include <linux/slab.h> - -extern struct marker __start___markers[]; -extern struct marker __stop___markers[]; - -/* Set to 1 to enable marker debug output */ -static const int marker_debug; - -/* - * markers_mutex nests inside module_mutex. Markers mutex protects the builtin - * and module markers and the hash table. - */ -static DEFINE_MUTEX(markers_mutex); - -/* - * Marker hash table, containing the active markers. - * Protected by module_mutex. - */ -#define MARKER_HASH_BITS 6 -#define MARKER_TABLE_SIZE (1 << MARKER_HASH_BITS) -static struct hlist_head marker_table[MARKER_TABLE_SIZE]; - -/* - * Note about RCU : - * It is used to make sure every handler has finished using its private data - * between two consecutive operation (add or remove) on a given marker. It is - * also used to delay the free of multiple probes array until a quiescent state - * is reached. - * marker entries modifications are protected by the markers_mutex. - */ -struct marker_entry { - struct hlist_node hlist; - char *format; - /* Probe wrapper */ - void (*call)(const struct marker *mdata, void *call_private, ...); - struct marker_probe_closure single; - struct marker_probe_closure *multi; - int refcount; /* Number of times armed. 0 if disarmed. */ - struct rcu_head rcu; - void *oldptr; - int rcu_pending; - unsigned char ptype:1; - unsigned char format_allocated:1; - char name[0]; /* Contains name'\0'format'\0' */ -}; - -/** - * __mark_empty_function - Empty probe callback - * @probe_private: probe private data - * @call_private: call site private data - * @fmt: format string - * @...: variable argument list - * - * Empty callback provided as a probe to the markers. By providing this to a - * disabled marker, we make sure the execution flow is always valid even - * though the function pointer change and the marker enabling are two distinct - * operations that modifies the execution flow of preemptible code. - */ -notrace void __mark_empty_function(void *probe_private, void *call_private, - const char *fmt, va_list *args) -{ -} -EXPORT_SYMBOL_GPL(__mark_empty_function); - -/* - * marker_probe_cb Callback that prepares the variable argument list for probes. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Since we do not use "typical" pointer based RCU in the 1 argument case, we - * need to put a full smp_rmb() in this branch. This is why we do not use - * rcu_dereference() for the pointer read. - */ -notrace void marker_probe_cb(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; - char ptype; - - /* - * rcu_read_lock_sched does two things : disabling preemption to make - * sure the teardown of the callbacks can be done correctly when they - * are in modules and they insure RCU read coherency. - */ - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - va_start(args, call_private); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - va_end(args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) { - va_start(args, call_private); - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - va_end(args); - } - } - rcu_read_unlock_sched_notrace(); -} -EXPORT_SYMBOL_GPL(marker_probe_cb); - -/* - * marker_probe_cb Callback that does not prepare the variable argument list. - * @mdata: pointer of type struct marker - * @call_private: caller site private data - * @...: Variable argument list. - * - * Should be connected to markers "MARK_NOARGS". - */ -static notrace void marker_probe_cb_noarg(const struct marker *mdata, - void *call_private, ...) -{ - va_list args; /* not initialized */ - char ptype; - - rcu_read_lock_sched_notrace(); - ptype = mdata->ptype; - if (likely(!ptype)) { - marker_probe_func *func; - /* Must read the ptype before ptr. They are not data dependant, - * so we put an explicit smp_rmb() here. */ - smp_rmb(); - func = mdata->single.func; - /* Must read the ptr before private data. They are not data - * dependant, so we put an explicit smp_rmb() here. */ - smp_rmb(); - func(mdata->single.probe_private, call_private, mdata->format, - &args); - } else { - struct marker_probe_closure *multi; - int i; - /* - * Read mdata->ptype before mdata->multi. - */ - smp_rmb(); - multi = mdata->multi; - /* - * multi points to an array, therefore accessing the array - * depends on reading multi. However, even in this case, - * we must insure that the pointer is read _before_ the array - * data. Same as rcu_dereference, but we need a full smp_rmb() - * in the fast path, so put the explicit barrier here. - */ - smp_read_barrier_depends(); - for (i = 0; multi[i].func; i++) - multi[i].func(multi[i].probe_private, call_private, - mdata->format, &args); - } - rcu_read_unlock_sched_notrace(); -} - -static void free_old_closure(struct rcu_head *head) -{ - struct marker_entry *entry = container_of(head, - struct marker_entry, rcu); - kfree(entry->oldptr); - /* Make sure we free the data before setting the pending flag to 0 */ - smp_wmb(); - entry->rcu_pending = 0; -} - -static void debug_print_probes(struct marker_entry *entry) -{ - int i; - - if (!marker_debug) - return; - - if (!entry->ptype) { - printk(KERN_DEBUG "Single probe : %p %p\n", - entry->single.func, - entry->single.probe_private); - } else { - for (i = 0; entry->multi[i].func; i++) - printk(KERN_DEBUG "Multi probe %d : %p %p\n", i, - entry->multi[i].func, - entry->multi[i].probe_private); - } -} - -static struct marker_probe_closure * -marker_entry_add_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0; - struct marker_probe_closure *old, *new; - - WARN_ON(!probe); - - debug_print_probes(entry); - old = entry->multi; - if (!entry->ptype) { - if (entry->single.func == probe && - entry->single.probe_private == probe_private) - return ERR_PTR(-EBUSY); - if (entry->single.func == __mark_empty_function) { - /* 0 -> 1 probes */ - entry->single.func = probe; - entry->single.probe_private = probe_private; - entry->refcount = 1; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* 1 -> 2 probes */ - nr_probes = 1; - old = NULL; - } - } else { - /* (N -> N+1), (N != 0, 1) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) - if (old[nr_probes].func == probe - && old[nr_probes].probe_private - == probe_private) - return ERR_PTR(-EBUSY); - } - /* + 2 : one for new probe, one for NULL func */ - new = kzalloc((nr_probes + 2) * sizeof(struct marker_probe_closure), - GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - if (!old) - new[0] = entry->single; - else - memcpy(new, old, - nr_probes * sizeof(struct marker_probe_closure)); - new[nr_probes].func = probe; - new[nr_probes].probe_private = probe_private; - entry->refcount = nr_probes + 1; - entry->multi = new; - entry->ptype = 1; - debug_print_probes(entry); - return old; -} - -static struct marker_probe_closure * -marker_entry_remove_probe(struct marker_entry *entry, - marker_probe_func *probe, void *probe_private) -{ - int nr_probes = 0, nr_del = 0, i; - struct marker_probe_closure *old, *new; - - old = entry->multi; - - debug_print_probes(entry); - if (!entry->ptype) { - /* 0 -> N is an error */ - WARN_ON(entry->single.func == __mark_empty_function); - /* 1 -> 0 probes */ - WARN_ON(probe && entry->single.func != probe); - WARN_ON(entry->single.probe_private != probe_private); - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - debug_print_probes(entry); - return NULL; - } else { - /* (N -> M), (N > 1, M >= 0) probes */ - for (nr_probes = 0; old[nr_probes].func; nr_probes++) { - if ((!probe || old[nr_probes].func == probe) - && old[nr_probes].probe_private - == probe_private) - nr_del++; - } - } - - if (nr_probes - nr_del == 0) { - /* N -> 0, (N > 1) */ - entry->single.func = __mark_empty_function; - entry->refcount = 0; - entry->ptype = 0; - } else if (nr_probes - nr_del == 1) { - /* N -> 1, (N > 1) */ - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - entry->single = old[i]; - entry->refcount = 1; - entry->ptype = 0; - } else { - int j = 0; - /* N -> M, (N > 1, M > 1) */ - /* + 1 for NULL */ - new = kzalloc((nr_probes - nr_del + 1) - * sizeof(struct marker_probe_closure), GFP_KERNEL); - if (new == NULL) - return ERR_PTR(-ENOMEM); - for (i = 0; old[i].func; i++) - if ((probe && old[i].func != probe) || - old[i].probe_private != probe_private) - new[j++] = old[i]; - entry->refcount = nr_probes - nr_del; - entry->ptype = 1; - entry->multi = new; - } - debug_print_probes(entry); - return old; -} - -/* - * Get marker if the marker is present in the marker hash table. - * Must be called with markers_mutex held. - * Returns NULL if not present. - */ -static struct marker_entry *get_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - u32 hash = jhash(name, strlen(name), 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) - return e; - } - return NULL; -} - -/* - * Add the marker to the marker hash table. Must be called with markers_mutex - * held. - */ -static struct marker_entry *add_marker(const char *name, const char *format) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - size_t format_len = 0; - u32 hash = jhash(name, name_len-1, 0); - - if (format) - format_len = strlen(format) + 1; - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - printk(KERN_NOTICE - "Marker %s busy\n", name); - return ERR_PTR(-EBUSY); /* Already there */ - } - } - /* - * Using kmalloc here to allocate a variable length element. Could - * cause some memory fragmentation if overused. - */ - e = kmalloc(sizeof(struct marker_entry) + name_len + format_len, - GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - memcpy(&e->name[0], name, name_len); - if (format) { - e->format = &e->name[name_len]; - memcpy(e->format, format, format_len); - if (strcmp(e->format, MARK_NOARGS) == 0) - e->call = marker_probe_cb_noarg; - else - e->call = marker_probe_cb; - trace_mark(core_marker_format, "name %s format %s", - e->name, e->format); - } else { - e->format = NULL; - e->call = marker_probe_cb; - } - e->single.func = __mark_empty_function; - e->single.probe_private = NULL; - e->multi = NULL; - e->ptype = 0; - e->format_allocated = 0; - e->refcount = 0; - e->rcu_pending = 0; - hlist_add_head(&e->hlist, head); - return e; -} - -/* - * Remove the marker from the marker hash table. Must be called with mutex_lock - * held. - */ -static int remove_marker(const char *name) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - int found = 0; - size_t len = strlen(name) + 1; - u32 hash = jhash(name, len-1, 0); - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - found = 1; - break; - } - } - if (!found) - return -ENOENT; - if (e->single.func != __mark_empty_function) - return -EBUSY; - hlist_del(&e->hlist); - if (e->format_allocated) - kfree(e->format); - /* Make sure the call_rcu has been executed */ - if (e->rcu_pending) - rcu_barrier_sched(); - kfree(e); - return 0; -} - -/* - * Set the mark_entry format to the format found in the element. - */ -static int marker_set_format(struct marker_entry *entry, const char *format) -{ - entry->format = kstrdup(format, GFP_KERNEL); - if (!entry->format) - return -ENOMEM; - entry->format_allocated = 1; - - trace_mark(core_marker_format, "name %s format %s", - entry->name, entry->format); - return 0; -} - -/* - * Sets the probe callback corresponding to one marker. - */ -static int set_marker(struct marker_entry *entry, struct marker *elem, - int active) -{ - int ret = 0; - WARN_ON(strcmp(entry->name, elem->name) != 0); - - if (entry->format) { - if (strcmp(entry->format, elem->format) != 0) { - printk(KERN_NOTICE - "Format mismatch for probe %s " - "(%s), marker (%s)\n", - entry->name, - entry->format, - elem->format); - return -EPERM; - } - } else { - ret = marker_set_format(entry, elem->format); - if (ret) - return ret; - } - - /* - * probe_cb setup (statically known) is done here. It is - * asynchronous with the rest of execution, therefore we only - * pass from a "safe" callback (with argument) to an "unsafe" - * callback (does not set arguments). - */ - elem->call = entry->call; - /* - * Sanity check : - * We only update the single probe private data when the ptr is - * set to a _non_ single probe! (0 -> 1 and N -> 1, N != 1) - */ - WARN_ON(elem->single.func != __mark_empty_function - && elem->single.probe_private != entry->single.probe_private - && !elem->ptype); - elem->single.probe_private = entry->single.probe_private; - /* - * Make sure the private data is valid when we update the - * single probe ptr. - */ - smp_wmb(); - elem->single.func = entry->single.func; - /* - * We also make sure that the new probe callbacks array is consistent - * before setting a pointer to it. - */ - rcu_assign_pointer(elem->multi, entry->multi); - /* - * Update the function or multi probe array pointer before setting the - * ptype. - */ - smp_wmb(); - elem->ptype = entry->ptype; - - if (elem->tp_name && (active ^ elem->state)) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - - if (active) { - /* - * try_module_get should always succeed because we hold - * lock_module() to get the tp_cb address. - */ - ret = try_module_get(__module_text_address( - (unsigned long)elem->tp_cb)); - BUG_ON(!ret); - ret = tracepoint_probe_register_noupdate( - elem->tp_name, - elem->tp_cb); - } else { - ret = tracepoint_probe_unregister_noupdate( - elem->tp_name, - elem->tp_cb); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address( - (unsigned long)elem->tp_cb)); - } - } - elem->state = active; - - return ret; -} - -/* - * Disable a marker and its probe callback. - * Note: only waiting an RCU period after setting elem->call to the empty - * function insures that the original callback is not used anymore. This insured - * by rcu_read_lock_sched around the call site. - */ -static void disable_marker(struct marker *elem) -{ - int ret; - - /* leave "call" as is. It is known statically. */ - if (elem->tp_name && elem->state) { - WARN_ON(!elem->tp_cb); - /* - * It is ok to directly call the probe registration because type - * checking has been done in the __trace_mark_tp() macro. - */ - ret = tracepoint_probe_unregister_noupdate(elem->tp_name, - elem->tp_cb); - WARN_ON(ret); - /* - * tracepoint_probe_update_all() must be called - * before the module containing tp_cb is unloaded. - */ - module_put(__module_text_address((unsigned long)elem->tp_cb)); - } - elem->state = 0; - elem->single.func = __mark_empty_function; - /* Update the function before setting the ptype */ - smp_wmb(); - elem->ptype = 0; /* single probe */ - /* - * Leave the private data and id there, because removal is racy and - * should be done only after an RCU period. These are never used until - * the next initialization anyway. - */ -} - -/** - * marker_update_probe_range - Update a probe range - * @begin: beginning of the range - * @end: end of the range - * - * Updates the probe callback corresponding to a range of markers. - */ -void marker_update_probe_range(struct marker *begin, - struct marker *end) -{ - struct marker *iter; - struct marker_entry *mark_entry; - - mutex_lock(&markers_mutex); - for (iter = begin; iter < end; iter++) { - mark_entry = get_marker(iter->name); - if (mark_entry) { - set_marker(mark_entry, iter, !!mark_entry->refcount); - /* - * ignore error, continue - */ - } else { - disable_marker(iter); - } - } - mutex_unlock(&markers_mutex); -} - -/* - * Update probes, removing the faulty probes. - * - * Internal callback only changed before the first probe is connected to it. - * Single probe private data can only be changed on 0 -> 1 and 2 -> 1 - * transitions. All other transitions will leave the old private data valid. - * This makes the non-atomicity of the callback/private data updates valid. - * - * "special case" updates : - * 0 -> 1 callback - * 1 -> 0 callback - * 1 -> 2 callbacks - * 2 -> 1 callbacks - * Other updates all behave the same, just like the 2 -> 3 or 3 -> 2 updates. - * Site effect : marker_set_format may delete the marker entry (creating a - * replacement). - */ -static void marker_update_probes(void) -{ - /* Core kernel markers */ - marker_update_probe_range(__start___markers, __stop___markers); - /* Markers in modules. */ - module_update_markers(); - tracepoint_probe_update_all(); -} - -/** - * marker_probe_register - Connect a probe to a marker - * @name: marker name - * @format: format string - * @probe: probe handler - * @probe_private: probe private data - * - * private data must be a valid allocated memory address, or NULL. - * Returns 0 if ok, error value on error. - * The probe address must at least be aligned on the architecture pointer size. - */ -int marker_probe_register(const char *name, const char *format, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) { - entry = add_marker(name, format); - if (IS_ERR(entry)) - ret = PTR_ERR(entry); - } else if (format) { - if (!entry->format) - ret = marker_set_format(entry, format); - else if (strcmp(entry->format, format)) - ret = -EPERM; - } - if (ret) - goto end; - - /* - * If we detect that a call_rcu is pending for this marker, - * make sure it's executed now. - */ - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_add_probe(entry, probe, probe_private); - if (IS_ERR(old)) { - ret = PTR_ERR(old); - goto end; - } - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_register); - -/** - * marker_probe_unregister - Disconnect a probe from a marker - * @name: marker name - * @probe: probe function pointer - * @probe_private: probe private data - * - * Returns the private data given to marker_probe_register, or an ERR_PTR(). - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister(const char *name, - marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - struct marker_probe_closure *old; - int ret = -ENOENT; - - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, probe, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker(name); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(name); /* Ignore busy error message */ - ret = 0; -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister); - -static struct marker_entry * -get_marker_from_private_data(marker_probe_func *probe, void *probe_private) -{ - struct marker_entry *entry; - unsigned int i; - struct hlist_head *head; - struct hlist_node *node; - - for (i = 0; i < MARKER_TABLE_SIZE; i++) { - head = &marker_table[i]; - hlist_for_each_entry(entry, node, head, hlist) { - if (!entry->ptype) { - if (entry->single.func == probe - && entry->single.probe_private - == probe_private) - return entry; - } else { - struct marker_probe_closure *closure; - closure = entry->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func == probe && - closure[i].probe_private - == probe_private) - return entry; - } - } - } - } - return NULL; -} - -/** - * marker_probe_unregister_private_data - Disconnect a probe from a marker - * @probe: probe function - * @probe_private: probe private data - * - * Unregister a probe by providing the registered private data. - * Only removes the first marker found in hash table. - * Return 0 on success or error value. - * We do not need to call a synchronize_sched to make sure the probes have - * finished running before doing a module unload, because the module unload - * itself uses stop_machine(), which insures that every preempt disabled section - * have finished. - */ -int marker_probe_unregister_private_data(marker_probe_func *probe, - void *probe_private) -{ - struct marker_entry *entry; - int ret = 0; - struct marker_probe_closure *old; - - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) { - ret = -ENOENT; - goto end; - } - if (entry->rcu_pending) - rcu_barrier_sched(); - old = marker_entry_remove_probe(entry, NULL, probe_private); - mutex_unlock(&markers_mutex); - marker_update_probes(); - mutex_lock(&markers_mutex); - entry = get_marker_from_private_data(probe, probe_private); - if (!entry) - goto end; - if (entry->rcu_pending) - rcu_barrier_sched(); - entry->oldptr = old; - entry->rcu_pending = 1; - /* write rcu_pending before calling the RCU callback */ - smp_wmb(); - call_rcu_sched(&entry->rcu, free_old_closure); - remove_marker(entry->name); /* Ignore busy error message */ -end: - mutex_unlock(&markers_mutex); - return ret; -} -EXPORT_SYMBOL_GPL(marker_probe_unregister_private_data); - -/** - * marker_get_private_data - Get a marker's probe private data - * @name: marker name - * @probe: probe to match - * @num: get the nth matching probe's private data - * - * Returns the nth private data pointer (starting from 0) matching, or an - * ERR_PTR. - * Returns the private data pointer, or an ERR_PTR. - * The private data pointer should _only_ be dereferenced if the caller is the - * owner of the data, or its content could vanish. This is mostly used to - * confirm that a caller is the owner of a registered probe. - */ -void *marker_get_private_data(const char *name, marker_probe_func *probe, - int num) -{ - struct hlist_head *head; - struct hlist_node *node; - struct marker_entry *e; - size_t name_len = strlen(name) + 1; - u32 hash = jhash(name, name_len-1, 0); - int i; - - head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (!strcmp(name, e->name)) { - if (!e->ptype) { - if (num == 0 && e->single.func == probe) - return e->single.probe_private; - } else { - struct marker_probe_closure *closure; - int match = 0; - closure = e->multi; - for (i = 0; closure[i].func; i++) { - if (closure[i].func != probe) - continue; - if (match++ == num) - return closure[i].probe_private; - } - } - break; - } - } - return ERR_PTR(-ENOENT); -} -EXPORT_SYMBOL_GPL(marker_get_private_data); - -#ifdef CONFIG_MODULES - -int marker_module_notify(struct notifier_block *self, - unsigned long val, void *data) -{ - struct module *mod = data; - - switch (val) { - case MODULE_STATE_COMING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - case MODULE_STATE_GOING: - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - break; - } - return 0; -} - -struct notifier_block marker_module_nb = { - .notifier_call = marker_module_notify, - .priority = 0, -}; - -static int init_markers(void) -{ - return register_module_notifier(&marker_module_nb); -} -__initcall(init_markers); - -#endif /* CONFIG_MODULES */ diff --git a/kernel/module.c b/kernel/module.c index 05ce49ced8f..b6ee424245d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2237,10 +2237,6 @@ static noinline struct module *load_module(void __user *umod, sizeof(*mod->ctors), &mod->num_ctors); #endif -#ifdef CONFIG_MARKERS - mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers", - sizeof(*mod->markers), &mod->num_markers); -#endif #ifdef CONFIG_TRACEPOINTS mod->tracepoints = section_objs(hdr, sechdrs, secstrings, "__tracepoints", @@ -2958,20 +2954,6 @@ void module_layout(struct module *mod, EXPORT_SYMBOL(module_layout); #endif -#ifdef CONFIG_MARKERS -void module_update_markers(void) -{ - struct module *mod; - - mutex_lock(&module_mutex); - list_for_each_entry(mod, &modules, list) - if (!mod->taints) - marker_update_probe_range(mod->markers, - mod->markers + mod->num_markers); - mutex_unlock(&module_mutex); -} -#endif - #ifdef CONFIG_TRACEPOINTS void module_update_tracepoints(void) { diff --git a/kernel/sched.c b/kernel/sched.c index d9db3fb1757..faf4d463bbf 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -119,8 +119,6 @@ */ #define RUNTIME_INF ((u64)~0ULL) -static void double_rq_lock(struct rq *rq1, struct rq *rq2); - static inline int rt_policy(int policy) { if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) @@ -378,13 +376,6 @@ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) #else -#ifdef CONFIG_SMP -static int root_task_group_empty(void) -{ - return 1; -} -#endif - static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } static inline struct task_group *task_group(struct task_struct *p) { @@ -514,14 +505,6 @@ struct root_domain { #ifdef CONFIG_SMP struct cpupri cpupri; #endif -#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) - /* - * Preferred wake up cpu nominated by sched_mc balance that will be - * used when most cpus are idle in the system indicating overall very - * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) - */ - unsigned int sched_mc_preferred_wakeup_cpu; -#endif }; /* @@ -646,9 +629,10 @@ struct rq { static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) +static inline +void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) { - rq->curr->sched_class->check_preempt_curr(rq, p, sync); + rq->curr->sched_class->check_preempt_curr(rq, p, flags); } static inline int cpu_of(struct rq *rq) @@ -1509,8 +1493,65 @@ static int tg_nop(struct task_group *tg, void *data) #endif #ifdef CONFIG_SMP -static unsigned long source_load(int cpu, int type); -static unsigned long target_load(int cpu, int type); +/* Used instead of source_load when we know the type == 0 */ +static unsigned long weighted_cpuload(const int cpu) +{ + return cpu_rq(cpu)->load.weight; +} + +/* + * Return a low guess at the load of a migration-source cpu weighted + * according to the scheduling class and "nice" value. + * + * We want to under-estimate the load of migration sources, to + * balance conservatively. + */ +static unsigned long source_load(int cpu, int type) +{ + struct rq *rq = cpu_rq(cpu); + unsigned long total = weighted_cpuload(cpu); + + if (type == 0 || !sched_feat(LB_BIAS)) + return total; + + return min(rq->cpu_load[type-1], total); +} + +/* + * Return a high guess at the load of a migration-target cpu weighted + * according to the scheduling class and "nice" value. + */ +static unsigned long target_load(int cpu, int type) +{ + struct rq *rq = cpu_rq(cpu); + unsigned long total = weighted_cpuload(cpu); + + if (type == 0 || !sched_feat(LB_BIAS)) + return total; + + return max(rq->cpu_load[type-1], total); +} + +static struct sched_group *group_of(int cpu) +{ + struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); + + if (!sd) + return NULL; + + return sd->groups; +} + +static unsigned long power_of(int cpu) +{ + struct sched_group *group = group_of(cpu); + + if (!group) + return SCHED_LOAD_SCALE; + + return group->cpu_power; +} + static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); static unsigned long cpu_avg_load_per_task(int cpu) @@ -1695,6 +1736,8 @@ static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) #ifdef CONFIG_PREEMPT +static void double_rq_lock(struct rq *rq1, struct rq *rq2); + /* * fair double_lock_balance: Safely acquires both rq->locks in a fair * way at the expense of forcing extra atomic operations in all @@ -1959,13 +2002,6 @@ static inline void check_class_changed(struct rq *rq, struct task_struct *p, } #ifdef CONFIG_SMP - -/* Used instead of source_load when we know the type == 0 */ -static unsigned long weighted_cpuload(const int cpu) -{ - return cpu_rq(cpu)->load.weight; -} - /* * Is this task likely cache-hot: */ @@ -2239,185 +2275,6 @@ void kick_process(struct task_struct *p) preempt_enable(); } EXPORT_SYMBOL_GPL(kick_process); - -/* - * Return a low guess at the load of a migration-source cpu weighted - * according to the scheduling class and "nice" value. - * - * We want to under-estimate the load of migration sources, to - * balance conservatively. - */ -static unsigned long source_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return min(rq->cpu_load[type-1], total); -} - -/* - * Return a high guess at the load of a migration-target cpu weighted - * according to the scheduling class and "nice" value. - */ -static unsigned long target_load(int cpu, int type) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - - if (type == 0 || !sched_feat(LB_BIAS)) - return total; - - return max(rq->cpu_load[type-1], total); -} - -/* - * find_idlest_group finds and returns the least busy CPU group within the - * domain. - */ -static struct sched_group * -find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) -{ - struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; - unsigned long min_load = ULONG_MAX, this_load = 0; - int load_idx = sd->forkexec_idx; - int imbalance = 100 + (sd->imbalance_pct-100)/2; - - do { - unsigned long load, avg_load; - int local_group; - int i; - - /* Skip over this group if it has no CPUs allowed */ - if (!cpumask_intersects(sched_group_cpus(group), - &p->cpus_allowed)) - continue; - - local_group = cpumask_test_cpu(this_cpu, - sched_group_cpus(group)); - - /* Tally up the load of all CPUs in the group */ - avg_load = 0; - - for_each_cpu(i, sched_group_cpus(group)) { - /* Bias balancing toward cpus of our domain */ - if (local_group) - load = source_load(i, load_idx); - else - load = target_load(i, load_idx); - - avg_load += load; - } - - /* Adjust by relative CPU power of the group */ - avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power; - - if (local_group) { - this_load = avg_load; - this = group; - } else if (avg_load < min_load) { - min_load = avg_load; - idlest = group; - } - } while (group = group->next, group != sd->groups); - - if (!idlest || 100*this_load < imbalance*min_load) - return NULL; - return idlest; -} - -/* - * find_idlest_cpu - find the idlest cpu among the cpus in group. - */ -static int -find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) -{ - unsigned long load, min_load = ULONG_MAX; - int idlest = -1; - int i; - - /* Traverse only the allowed CPUs */ - for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { - load = weighted_cpuload(i); - - if (load < min_load || (load == min_load && i == this_cpu)) { - min_load = load; - idlest = i; - } - } - - return idlest; -} - -/* - * sched_balance_self: balance the current task (running on cpu) in domains - * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and - * SD_BALANCE_EXEC. - * - * Balance, ie. select the least loaded group. - * - * Returns the target CPU number, or the same CPU if no balancing is needed. - * - * preempt must be disabled. - */ -static int sched_balance_self(int cpu, int flag) -{ - struct task_struct *t = current; - struct sched_domain *tmp, *sd = NULL; - - for_each_domain(cpu, tmp) { - /* - * If power savings logic is enabled for a domain, stop there. - */ - if (tmp->flags & SD_POWERSAVINGS_BALANCE) - break; - if (tmp->flags & flag) - sd = tmp; - } - - if (sd) - update_shares(sd); - - while (sd) { - struct sched_group *group; - int new_cpu, weight; - - if (!(sd->flags & flag)) { - sd = sd->child; - continue; - } - - group = find_idlest_group(sd, t, cpu); - if (!group) { - sd = sd->child; - continue; - } - - new_cpu = find_idlest_cpu(group, t, cpu); - if (new_cpu == -1 || new_cpu == cpu) { - /* Now try balancing at a lower domain level of cpu */ - sd = sd->child; - continue; - } - - /* Now try balancing at a lower domain level of new_cpu */ - cpu = new_cpu; - weight = cpumask_weight(sched_domain_span(sd)); - sd = NULL; - for_each_domain(cpu, tmp) { - if (weight <= cpumask_weight(sched_domain_span(tmp))) - break; - if (tmp->flags & flag) - sd = tmp; - } - /* while loop will break here if sd == NULL */ - } - - return cpu; -} - #endif /* CONFIG_SMP */ /** @@ -2455,37 +2312,22 @@ void task_oncpu_function_call(struct task_struct *p, * * returns failure only if the task is already active. */ -static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) +static int try_to_wake_up(struct task_struct *p, unsigned int state, + int wake_flags) { int cpu, orig_cpu, this_cpu, success = 0; unsigned long flags; - long old_state; struct rq *rq; if (!sched_feat(SYNC_WAKEUPS)) - sync = 0; - -#ifdef CONFIG_SMP - if (sched_feat(LB_WAKEUP_UPDATE) && !root_task_group_empty()) { - struct sched_domain *sd; + wake_flags &= ~WF_SYNC; - this_cpu = raw_smp_processor_id(); - cpu = task_cpu(p); - - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { - update_shares(sd); - break; - } - } - } -#endif + this_cpu = get_cpu(); smp_wmb(); rq = task_rq_lock(p, &flags); update_rq_clock(rq); - old_state = p->state; - if (!(old_state & state)) + if (!(p->state & state)) goto out; if (p->se.on_rq) @@ -2493,27 +2335,29 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) cpu = task_cpu(p); orig_cpu = cpu; - this_cpu = smp_processor_id(); #ifdef CONFIG_SMP if (unlikely(task_running(rq, p))) goto out_activate; - cpu = p->sched_class->select_task_rq(p, sync); - if (cpu != orig_cpu) { + /* + * In order to handle concurrent wakeups and release the rq->lock + * we put the task in TASK_WAKING state. + * + * First fix up the nr_uninterruptible count: + */ + if (task_contributes_to_load(p)) + rq->nr_uninterruptible--; + p->state = TASK_WAKING; + task_rq_unlock(rq, &flags); + + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags); + if (cpu != orig_cpu) set_task_cpu(p, cpu); - task_rq_unlock(rq, &flags); - /* might preempt at this point */ - rq = task_rq_lock(p, &flags); - old_state = p->state; - if (!(old_state & state)) - goto out; - if (p->se.on_rq) - goto out_running; - this_cpu = smp_processor_id(); - cpu = task_cpu(p); - } + rq = task_rq_lock(p, &flags); + WARN_ON(p->state != TASK_WAKING); + cpu = task_cpu(p); #ifdef CONFIG_SCHEDSTATS schedstat_inc(rq, ttwu_count); @@ -2533,7 +2377,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) out_activate: #endif /* CONFIG_SMP */ schedstat_inc(p, se.nr_wakeups); - if (sync) + if (wake_flags & WF_SYNC) schedstat_inc(p, se.nr_wakeups_sync); if (orig_cpu != cpu) schedstat_inc(p, se.nr_wakeups_migrate); @@ -2562,7 +2406,7 @@ out_activate: out_running: trace_sched_wakeup(rq, p, success); - check_preempt_curr(rq, p, sync); + check_preempt_curr(rq, p, wake_flags); p->state = TASK_RUNNING; #ifdef CONFIG_SMP @@ -2571,6 +2415,7 @@ out_running: #endif out: task_rq_unlock(rq, &flags); + put_cpu(); return success; } @@ -2613,6 +2458,7 @@ static void __sched_fork(struct task_struct *p) p->se.avg_overlap = 0; p->se.start_runtime = 0; p->se.avg_wakeup = sysctl_sched_wakeup_granularity; + p->se.avg_running = 0; #ifdef CONFIG_SCHEDSTATS p->se.wait_start = 0; @@ -2674,11 +2520,6 @@ void sched_fork(struct task_struct *p, int clone_flags) __sched_fork(p); -#ifdef CONFIG_SMP - cpu = sched_balance_self(cpu, SD_BALANCE_FORK); -#endif - set_task_cpu(p, cpu); - /* * Make sure we do not leak PI boosting priority to the child. */ @@ -2709,6 +2550,11 @@ void sched_fork(struct task_struct *p, int clone_flags) if (!rt_prio(p->prio)) p->sched_class = &fair_sched_class; +#ifdef CONFIG_SMP + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0); +#endif + set_task_cpu(p, cpu); + #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) memset(&p->sched_info, 0, sizeof(p->sched_info)); @@ -2754,7 +2600,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) inc_nr_running(rq); } trace_sched_wakeup_new(rq, p, 1); - check_preempt_curr(rq, p, 0); + check_preempt_curr(rq, p, WF_FORK); #ifdef CONFIG_SMP if (p->sched_class->task_wake_up) p->sched_class->task_wake_up(rq, p); @@ -3263,7 +3109,7 @@ out: void sched_exec(void) { int new_cpu, this_cpu = get_cpu(); - new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); + new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0); put_cpu(); if (new_cpu != this_cpu) sched_migrate_task(current, new_cpu); @@ -3683,11 +3529,6 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, *imbalance = sds->min_load_per_task; sds->busiest = sds->group_min; - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = - group_first_cpu(sds->group_leader); - } - return 1; } @@ -3711,7 +3552,18 @@ static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, } #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ -unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) + +unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return SCHED_LOAD_SCALE; +} + +unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) +{ + return default_scale_freq_power(sd, cpu); +} + +unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) { unsigned long weight = cpumask_weight(sched_domain_span(sd)); unsigned long smt_gain = sd->smt_gain; @@ -3721,6 +3573,11 @@ unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) return smt_gain; } +unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) +{ + return default_scale_smt_power(sd, cpu); +} + unsigned long scale_rt_power(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -3745,10 +3602,19 @@ static void update_cpu_power(struct sched_domain *sd, int cpu) unsigned long power = SCHED_LOAD_SCALE; struct sched_group *sdg = sd->groups; - /* here we could scale based on cpufreq */ + if (sched_feat(ARCH_POWER)) + power *= arch_scale_freq_power(sd, cpu); + else + power *= default_scale_freq_power(sd, cpu); + + power >>= SCHED_LOAD_SHIFT; if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { - power *= arch_scale_smt_power(sd, cpu); + if (sched_feat(ARCH_POWER)) + power *= arch_scale_smt_power(sd, cpu); + else + power *= default_scale_smt_power(sd, cpu); + power >>= SCHED_LOAD_SHIFT; } @@ -4161,26 +4027,6 @@ ret: return NULL; } -static struct sched_group *group_of(int cpu) -{ - struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); - - if (!sd) - return NULL; - - return sd->groups; -} - -static unsigned long power_of(int cpu) -{ - struct sched_group *group = group_of(cpu); - - if (!group) - return SCHED_LOAD_SCALE; - - return group->cpu_power; -} - /* * find_busiest_queue - find the busiest runqueue among the cpus in group. */ @@ -5465,14 +5311,13 @@ static inline void schedule_debug(struct task_struct *prev) #endif } -static void put_prev_task(struct rq *rq, struct task_struct *prev) +static void put_prev_task(struct rq *rq, struct task_struct *p) { - if (prev->state == TASK_RUNNING) { - u64 runtime = prev->se.sum_exec_runtime; + u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime; - runtime -= prev->se.prev_sum_exec_runtime; - runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); + update_avg(&p->se.avg_running, runtime); + if (p->state == TASK_RUNNING) { /* * In order to avoid avg_overlap growing stale when we are * indeed overlapping and hence not getting put to sleep, grow @@ -5482,9 +5327,12 @@ static void put_prev_task(struct rq *rq, struct task_struct *prev) * correlates to the amount of cache footprint a task can * build up. */ - update_avg(&prev->se.avg_overlap, runtime); + runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); + update_avg(&p->se.avg_overlap, runtime); + } else { + update_avg(&p->se.avg_running, 0); } - prev->sched_class->put_prev_task(rq, prev); + p->sched_class->put_prev_task(rq, p); } /* @@ -5716,10 +5564,10 @@ asmlinkage void __sched preempt_schedule_irq(void) #endif /* CONFIG_PREEMPT */ -int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, +int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, void *key) { - return try_to_wake_up(curr->private, mode, sync); + return try_to_wake_up(curr->private, mode, wake_flags); } EXPORT_SYMBOL(default_wake_function); @@ -5733,14 +5581,14 @@ EXPORT_SYMBOL(default_wake_function); * zero in this (rare) case, and we handle it by continuing to scan the queue. */ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, - int nr_exclusive, int sync, void *key) + int nr_exclusive, int wake_flags, void *key) { wait_queue_t *curr, *next; list_for_each_entry_safe(curr, next, &q->task_list, task_list) { unsigned flags = curr->flags; - if (curr->func(curr, mode, sync, key) && + if (curr->func(curr, mode, wake_flags, key) && (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) break; } @@ -5801,16 +5649,16 @@ void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, int nr_exclusive, void *key) { unsigned long flags; - int sync = 1; + int wake_flags = WF_SYNC; if (unlikely(!q)) return; if (unlikely(!nr_exclusive)) - sync = 0; + wake_flags = 0; spin_lock_irqsave(&q->lock, flags); - __wake_up_common(q, mode, nr_exclusive, sync, key); + __wake_up_common(q, mode, nr_exclusive, wake_flags, key); spin_unlock_irqrestore(&q->lock, flags); } EXPORT_SYMBOL_GPL(__wake_up_sync_key); @@ -8000,9 +7848,7 @@ static int sd_degenerate(struct sched_domain *sd) } /* Following flags don't use groups */ - if (sd->flags & (SD_WAKE_IDLE | - SD_WAKE_AFFINE | - SD_WAKE_BALANCE)) + if (sd->flags & (SD_WAKE_AFFINE)) return 0; return 1; @@ -8019,10 +7865,6 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) return 0; - /* Does parent contain flags not in child? */ - /* WAKE_BALANCE is a subset of WAKE_AFFINE */ - if (cflags & SD_WAKE_AFFINE) - pflags &= ~SD_WAKE_BALANCE; /* Flags needing groups don't count if only 1 group in parent */ if (parent->groups == parent->groups->next) { pflags &= ~(SD_LOAD_BALANCE | @@ -8708,10 +8550,10 @@ static void set_domain_attribute(struct sched_domain *sd, request = attr->relax_domain_level; if (request < sd->level) { /* turn off idle balance on this domain */ - sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); + sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); } else { /* turn on idle balance on this domain */ - sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); + sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); } } diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c index 5ddbd089126..efb84409bc4 100644 --- a/kernel/sched_debug.c +++ b/kernel/sched_debug.c @@ -395,6 +395,7 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m) PN(se.sum_exec_runtime); PN(se.avg_overlap); PN(se.avg_wakeup); + PN(se.avg_running); nr_switches = p->nvcsw + p->nivcsw; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index aa7f8412101..10d218ab69f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -711,7 +711,7 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) if (!initial) { /* sleeps upto a single latency don't count. */ - if (sched_feat(NEW_FAIR_SLEEPERS)) { + if (sched_feat(FAIR_SLEEPERS)) { unsigned long thresh = sysctl_sched_latency; /* @@ -725,6 +725,13 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) task_of(se)->policy != SCHED_IDLE)) thresh = calc_delta_fair(thresh, se); + /* + * Halve their sleep time's effect, to allow + * for a gentler effect of sleepers: + */ + if (sched_feat(GENTLE_FAIR_SLEEPERS)) + thresh >>= 1; + vruntime -= thresh; } } @@ -757,10 +764,10 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup) static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se) { - if (cfs_rq->last == se) + if (!se || cfs_rq->last == se) cfs_rq->last = NULL; - if (cfs_rq->next == se) + if (!se || cfs_rq->next == se) cfs_rq->next = NULL; } @@ -1062,83 +1069,6 @@ static void yield_task_fair(struct rq *rq) se->vruntime = rightmost->vruntime + 1; } -/* - * wake_idle() will wake a task on an idle cpu if task->cpu is - * not idle and an idle cpu is available. The span of cpus to - * search starts with cpus closest then further out as needed, - * so we always favor a closer, idle cpu. - * Domains may include CPUs that are not usable for migration, - * hence we need to mask them out (rq->rd->online) - * - * Returns the CPU we should wake onto. - */ -#if defined(ARCH_HAS_SCHED_WAKE_IDLE) - -#define cpu_rd_active(cpu, rq) cpumask_test_cpu(cpu, rq->rd->online) - -static int wake_idle(int cpu, struct task_struct *p) -{ - struct sched_domain *sd; - int i; - unsigned int chosen_wakeup_cpu; - int this_cpu; - struct rq *task_rq = task_rq(p); - - /* - * At POWERSAVINGS_BALANCE_WAKEUP level, if both this_cpu and prev_cpu - * are idle and this is not a kernel thread and this task's affinity - * allows it to be moved to preferred cpu, then just move! - */ - - this_cpu = smp_processor_id(); - chosen_wakeup_cpu = - cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu; - - if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP && - idle_cpu(cpu) && idle_cpu(this_cpu) && - p->mm && !(p->flags & PF_KTHREAD) && - cpu_isset(chosen_wakeup_cpu, p->cpus_allowed)) - return chosen_wakeup_cpu; - - /* - * If it is idle, then it is the best cpu to run this task. - * - * This cpu is also the best, if it has more than one task already. - * Siblings must be also busy(in most cases) as they didn't already - * pickup the extra load from this cpu and hence we need not check - * sibling runqueue info. This will avoid the checks and cache miss - * penalities associated with that. - */ - if (idle_cpu(cpu) || cpu_rq(cpu)->cfs.nr_running > 1) - return cpu; - - for_each_domain(cpu, sd) { - if ((sd->flags & SD_WAKE_IDLE) - || ((sd->flags & SD_WAKE_IDLE_FAR) - && !task_hot(p, task_rq->clock, sd))) { - for_each_cpu_and(i, sched_domain_span(sd), - &p->cpus_allowed) { - if (cpu_rd_active(i, task_rq) && idle_cpu(i)) { - if (i != task_cpu(p)) { - schedstat_inc(p, - se.nr_wakeups_idle); - } - return i; - } - } - } else { - break; - } - } - return cpu; -} -#else /* !ARCH_HAS_SCHED_WAKE_IDLE*/ -static inline int wake_idle(int cpu, struct task_struct *p) -{ - return cpu; -} -#endif - #ifdef CONFIG_SMP #ifdef CONFIG_FAIR_GROUP_SCHED @@ -1225,25 +1155,34 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu, #endif -static int -wake_affine(struct sched_domain *this_sd, struct rq *this_rq, - struct task_struct *p, int prev_cpu, int this_cpu, int sync, - int idx, unsigned long load, unsigned long this_load, - unsigned int imbalance) +static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync) { - struct task_struct *curr = this_rq->curr; - struct task_group *tg; - unsigned long tl = this_load; + struct task_struct *curr = current; + unsigned long this_load, load; + int idx, this_cpu, prev_cpu; unsigned long tl_per_task; + unsigned int imbalance; + struct task_group *tg; unsigned long weight; int balanced; - if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS)) - return 0; + idx = sd->wake_idx; + this_cpu = smp_processor_id(); + prev_cpu = task_cpu(p); + load = source_load(prev_cpu, idx); + this_load = target_load(this_cpu, idx); - if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost || - p->se.avg_overlap > sysctl_sched_migration_cost)) - sync = 0; + if (sync) { + if (sched_feat(SYNC_LESS) && + (curr->se.avg_overlap > sysctl_sched_migration_cost || + p->se.avg_overlap > sysctl_sched_migration_cost)) + sync = 0; + } else { + if (sched_feat(SYNC_MORE) && + (curr->se.avg_overlap < sysctl_sched_migration_cost && + p->se.avg_overlap < sysctl_sched_migration_cost)) + sync = 1; + } /* * If sync wakeup then subtract the (maximum possible) @@ -1254,24 +1193,26 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, tg = task_group(current); weight = current->se.load.weight; - tl += effective_load(tg, this_cpu, -weight, -weight); + this_load += effective_load(tg, this_cpu, -weight, -weight); load += effective_load(tg, prev_cpu, 0, -weight); } tg = task_group(p); weight = p->se.load.weight; + imbalance = 100 + (sd->imbalance_pct - 100) / 2; + /* * In low-load situations, where prev_cpu is idle and this_cpu is idle - * due to the sync cause above having dropped tl to 0, we'll always have - * an imbalance, but there's really nothing you can do about that, so - * that's good too. + * due to the sync cause above having dropped this_load to 0, we'll + * always have an imbalance, but there's really nothing you can do + * about that, so that's good too. * * Otherwise check if either cpus are near enough in load to allow this * task to be woken on this_cpu. */ - balanced = !tl || - 100*(tl + effective_load(tg, this_cpu, weight, weight)) <= + balanced = !this_load || + 100*(this_load + effective_load(tg, this_cpu, weight, weight)) <= imbalance*(load + effective_load(tg, prev_cpu, 0, weight)); /* @@ -1285,14 +1226,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, schedstat_inc(p, se.nr_wakeups_affine_attempts); tl_per_task = cpu_avg_load_per_task(this_cpu); - if (balanced || (tl <= load && tl + target_load(prev_cpu, idx) <= - tl_per_task)) { + if (balanced || + (this_load <= load && + this_load + target_load(prev_cpu, idx) <= tl_per_task)) { /* * This domain has SD_WAKE_AFFINE and * p is cache cold in this domain, and * there is no bad imbalance. */ - schedstat_inc(this_sd, ttwu_move_affine); + schedstat_inc(sd, ttwu_move_affine); schedstat_inc(p, se.nr_wakeups_affine); return 1; @@ -1300,65 +1242,215 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, return 0; } -static int select_task_rq_fair(struct task_struct *p, int sync) +/* + * find_idlest_group finds and returns the least busy CPU group within the + * domain. + */ +static struct sched_group * +find_idlest_group(struct sched_domain *sd, struct task_struct *p, + int this_cpu, int load_idx) { - struct sched_domain *sd, *this_sd = NULL; - int prev_cpu, this_cpu, new_cpu; - unsigned long load, this_load; - struct rq *this_rq; - unsigned int imbalance; - int idx; + struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; + unsigned long min_load = ULONG_MAX, this_load = 0; + int imbalance = 100 + (sd->imbalance_pct-100)/2; - prev_cpu = task_cpu(p); - this_cpu = smp_processor_id(); - this_rq = cpu_rq(this_cpu); - new_cpu = prev_cpu; + do { + unsigned long load, avg_load; + int local_group; + int i; - /* - * 'this_sd' is the first domain that both - * this_cpu and prev_cpu are present in: - */ - for_each_domain(this_cpu, sd) { - if (cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) { - this_sd = sd; - break; + /* Skip over this group if it has no CPUs allowed */ + if (!cpumask_intersects(sched_group_cpus(group), + &p->cpus_allowed)) + continue; + + local_group = cpumask_test_cpu(this_cpu, + sched_group_cpus(group)); + + /* Tally up the load of all CPUs in the group */ + avg_load = 0; + + for_each_cpu(i, sched_group_cpus(group)) { + /* Bias balancing toward cpus of our domain */ + if (local_group) + load = source_load(i, load_idx); + else + load = target_load(i, load_idx); + + avg_load += load; + } + + /* Adjust by relative CPU power of the group */ + avg_load = (avg_load * SCHED_LOAD_SCALE) / group->cpu_power; + + if (local_group) { + this_load = avg_load; + this = group; + } else if (avg_load < min_load) { + min_load = avg_load; + idlest = group; + } + } while (group = group->next, group != sd->groups); + + if (!idlest || 100*this_load < imbalance*min_load) + return NULL; + return idlest; +} + +/* + * find_idlest_cpu - find the idlest cpu among the cpus in group. + */ +static int +find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) +{ + unsigned long load, min_load = ULONG_MAX; + int idlest = -1; + int i; + + /* Traverse only the allowed CPUs */ + for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { + load = weighted_cpuload(i); + + if (load < min_load || (load == min_load && i == this_cpu)) { + min_load = load; + idlest = i; } } - if (unlikely(!cpumask_test_cpu(this_cpu, &p->cpus_allowed))) - goto out; + return idlest; +} - /* - * Check for affine wakeup and passive balancing possibilities. - */ - if (!this_sd) +/* + * sched_balance_self: balance the current task (running on cpu) in domains + * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and + * SD_BALANCE_EXEC. + * + * Balance, ie. select the least loaded group. + * + * Returns the target CPU number, or the same CPU if no balancing is needed. + * + * preempt must be disabled. + */ +static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) +{ + struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL; + int cpu = smp_processor_id(); + int prev_cpu = task_cpu(p); + int new_cpu = cpu; + int want_affine = 0; + int want_sd = 1; + int sync = wake_flags & WF_SYNC; + + if (sd_flag & SD_BALANCE_WAKE) { + if (sched_feat(AFFINE_WAKEUPS)) + want_affine = 1; + new_cpu = prev_cpu; + } + + rcu_read_lock(); + for_each_domain(cpu, tmp) { + /* + * If power savings logic is enabled for a domain, see if we + * are not overloaded, if so, don't balance wider. + */ + if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) { + unsigned long power = 0; + unsigned long nr_running = 0; + unsigned long capacity; + int i; + + for_each_cpu(i, sched_domain_span(tmp)) { + power += power_of(i); + nr_running += cpu_rq(i)->cfs.nr_running; + } + + capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); + + if (tmp->flags & SD_POWERSAVINGS_BALANCE) + nr_running /= 2; + + if (nr_running < capacity) + want_sd = 0; + } + + if (want_affine && (tmp->flags & SD_WAKE_AFFINE) && + cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) { + + affine_sd = tmp; + want_affine = 0; + } + + if (!want_sd && !want_affine) + break; + + if (!(tmp->flags & sd_flag)) + continue; + + if (want_sd) + sd = tmp; + } + + if (sched_feat(LB_SHARES_UPDATE)) { + /* + * Pick the largest domain to update shares over + */ + tmp = sd; + if (affine_sd && (!tmp || + cpumask_weight(sched_domain_span(affine_sd)) > + cpumask_weight(sched_domain_span(sd)))) + tmp = affine_sd; + + if (tmp) + update_shares(tmp); + } + + if (affine_sd && wake_affine(affine_sd, p, sync)) { + new_cpu = cpu; goto out; + } - idx = this_sd->wake_idx; + while (sd) { + int load_idx = sd->forkexec_idx; + struct sched_group *group; + int weight; - imbalance = 100 + (this_sd->imbalance_pct - 100) / 2; + if (!(sd->flags & sd_flag)) { + sd = sd->child; + continue; + } - load = source_load(prev_cpu, idx); - this_load = target_load(this_cpu, idx); + if (sd_flag & SD_BALANCE_WAKE) + load_idx = sd->wake_idx; - if (wake_affine(this_sd, this_rq, p, prev_cpu, this_cpu, sync, idx, - load, this_load, imbalance)) - return this_cpu; + group = find_idlest_group(sd, p, cpu, load_idx); + if (!group) { + sd = sd->child; + continue; + } - /* - * Start passive balancing when half the imbalance_pct - * limit is reached. - */ - if (this_sd->flags & SD_WAKE_BALANCE) { - if (imbalance*this_load <= 100*load) { - schedstat_inc(this_sd, ttwu_move_balance); - schedstat_inc(p, se.nr_wakeups_passive); - return this_cpu; + new_cpu = find_idlest_cpu(group, p, cpu); + if (new_cpu == -1 || new_cpu == cpu) { + /* Now try balancing at a lower domain level of cpu */ + sd = sd->child; + continue; } + + /* Now try balancing at a lower domain level of new_cpu */ + cpu = new_cpu; + weight = cpumask_weight(sched_domain_span(sd)); + sd = NULL; + for_each_domain(cpu, tmp) { + if (weight <= cpumask_weight(sched_domain_span(tmp))) + break; + if (tmp->flags & sd_flag) + sd = tmp; + } + /* while loop will break here if sd == NULL */ } out: - return wake_idle(new_cpu, p); + rcu_read_unlock(); + return new_cpu; } #endif /* CONFIG_SMP */ @@ -1471,11 +1563,12 @@ static void set_next_buddy(struct sched_entity *se) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) { struct task_struct *curr = rq->curr; struct sched_entity *se = &curr->se, *pse = &p->se; struct cfs_rq *cfs_rq = task_cfs_rq(curr); + int sync = wake_flags & WF_SYNC; update_curr(cfs_rq); @@ -1501,7 +1594,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) */ if (sched_feat(LAST_BUDDY) && likely(se->on_rq && curr != rq->idle)) set_last_buddy(se); - set_next_buddy(pse); + if (sched_feat(NEXT_BUDDY) && !(wake_flags & WF_FORK)) + set_next_buddy(pse); /* * We can come here with TIF_NEED_RESCHED already set from new task @@ -1523,16 +1617,25 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync) return; } - if (!sched_feat(WAKEUP_PREEMPT)) - return; - - if (sched_feat(WAKEUP_OVERLAP) && (sync || - (se->avg_overlap < sysctl_sched_migration_cost && - pse->avg_overlap < sysctl_sched_migration_cost))) { + if ((sched_feat(WAKEUP_SYNC) && sync) || + (sched_feat(WAKEUP_OVERLAP) && + (se->avg_overlap < sysctl_sched_migration_cost && + pse->avg_overlap < sysctl_sched_migration_cost))) { resched_task(curr); return; } + if (sched_feat(WAKEUP_RUNNING)) { + if (pse->avg_running < se->avg_running) { + set_next_buddy(pse); + resched_task(curr); + return; + } + } + + if (!sched_feat(WAKEUP_PREEMPT)) + return; + find_matching_se(&se, &pse); BUG_ON(!pse); @@ -1555,8 +1658,13 @@ static struct task_struct *pick_next_task_fair(struct rq *rq) /* * If se was a buddy, clear it so that it will have to earn * the favour again. + * + * If se was not a buddy, clear the buddies because neither + * was elegible to run, let them earn it again. + * + * IOW. unconditionally clear buddies. */ - __clear_buddies(cfs_rq, se); + __clear_buddies(cfs_rq, NULL); set_next_entity(cfs_rq, se); cfs_rq = group_cfs_rq(se); } while (cfs_rq); diff --git a/kernel/sched_features.h b/kernel/sched_features.h index e2dc63a5815..0d94083582c 100644 --- a/kernel/sched_features.h +++ b/kernel/sched_features.h @@ -1,17 +1,123 @@ -SCHED_FEAT(NEW_FAIR_SLEEPERS, 0) +/* + * Disregards a certain amount of sleep time (sched_latency_ns) and + * considers the task to be running during that period. This gives it + * a service deficit on wakeup, allowing it to run sooner. + */ +SCHED_FEAT(FAIR_SLEEPERS, 1) + +/* + * Only give sleepers 50% of their service deficit. This allows + * them to run sooner, but does not allow tons of sleepers to + * rip the spread apart. + */ +SCHED_FEAT(GENTLE_FAIR_SLEEPERS, 1) + +/* + * By not normalizing the sleep time, heavy tasks get an effective + * longer period, and lighter task an effective shorter period they + * are considered running. + */ SCHED_FEAT(NORMALIZED_SLEEPER, 0) -SCHED_FEAT(ADAPTIVE_GRAN, 1) -SCHED_FEAT(WAKEUP_PREEMPT, 1) + +/* + * Place new tasks ahead so that they do not starve already running + * tasks + */ SCHED_FEAT(START_DEBIT, 1) + +/* + * Should wakeups try to preempt running tasks. + */ +SCHED_FEAT(WAKEUP_PREEMPT, 1) + +/* + * Compute wakeup_gran based on task behaviour, clipped to + * [0, sched_wakeup_gran_ns] + */ +SCHED_FEAT(ADAPTIVE_GRAN, 1) + +/* + * When converting the wakeup granularity to virtual time, do it such + * that heavier tasks preempting a lighter task have an edge. + */ +SCHED_FEAT(ASYM_GRAN, 1) + +/* + * Always wakeup-preempt SYNC wakeups, see SYNC_WAKEUPS. + */ +SCHED_FEAT(WAKEUP_SYNC, 0) + +/* + * Wakeup preempt based on task behaviour. Tasks that do not overlap + * don't get preempted. + */ +SCHED_FEAT(WAKEUP_OVERLAP, 0) + +/* + * Wakeup preemption towards tasks that run short + */ +SCHED_FEAT(WAKEUP_RUNNING, 0) + +/* + * Use the SYNC wakeup hint, pipes and the likes use this to indicate + * the remote end is likely to consume the data we just wrote, and + * therefore has cache benefit from being placed on the same cpu, see + * also AFFINE_WAKEUPS. + */ +SCHED_FEAT(SYNC_WAKEUPS, 1) + +/* + * Based on load and program behaviour, see if it makes sense to place + * a newly woken task on the same cpu as the task that woke it -- + * improve cache locality. Typically used with SYNC wakeups as + * generated by pipes and the like, see also SYNC_WAKEUPS. + */ SCHED_FEAT(AFFINE_WAKEUPS, 1) + +/* + * Weaken SYNC hint based on overlap + */ +SCHED_FEAT(SYNC_LESS, 1) + +/* + * Add SYNC hint based on overlap + */ +SCHED_FEAT(SYNC_MORE, 0) + +/* + * Prefer to schedule the task we woke last (assuming it failed + * wakeup-preemption), since its likely going to consume data we + * touched, increases cache locality. + */ +SCHED_FEAT(NEXT_BUDDY, 0) + +/* + * Prefer to schedule the task that ran last (when we did + * wake-preempt) as that likely will touch the same data, increases + * cache locality. + */ +SCHED_FEAT(LAST_BUDDY, 1) + +/* + * Consider buddies to be cache hot, decreases the likelyness of a + * cache buddy being migrated away, increases cache locality. + */ SCHED_FEAT(CACHE_HOT_BUDDY, 1) -SCHED_FEAT(SYNC_WAKEUPS, 1) + +/* + * Use arch dependent cpu power functions + */ +SCHED_FEAT(ARCH_POWER, 0) + SCHED_FEAT(HRTICK, 0) SCHED_FEAT(DOUBLE_TICK, 0) -SCHED_FEAT(ASYM_GRAN, 1) SCHED_FEAT(LB_BIAS, 1) -SCHED_FEAT(LB_WAKEUP_UPDATE, 1) +SCHED_FEAT(LB_SHARES_UPDATE, 1) SCHED_FEAT(ASYM_EFF_LOAD, 1) -SCHED_FEAT(WAKEUP_OVERLAP, 0) -SCHED_FEAT(LAST_BUDDY, 1) + +/* + * Spin-wait on mutex acquisition when the mutex owner is running on + * another cpu -- assumes that when the owner is running, it will soon + * release the lock. Decreases scheduling overhead. + */ SCHED_FEAT(OWNER_SPIN, 1) diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 499672c10cb..a8b448af004 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,7 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sync) +static int select_task_rq_idle(struct task_struct *p, int sd_flag, int flags) { return task_cpu(p); /* IDLE tasks as never migrated */ } @@ -14,7 +14,7 @@ static int select_task_rq_idle(struct task_struct *p, int sync) /* * Idle tasks are unconditionally rescheduled: */ -static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_curr_idle(struct rq *rq, struct task_struct *p, int flags) { resched_task(rq->idle); } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 2eb4bd6a526..13de7126a6a 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -938,10 +938,13 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int sync) +static int select_task_rq_rt(struct task_struct *p, int sd_flag, int flags) { struct rq *rq = task_rq(p); + if (sd_flag != SD_BALANCE_WAKE) + return smp_processor_id(); + /* * If the current task is an RT task, then * try to see if we can wake this RT task up on another @@ -999,7 +1002,7 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) /* * Preempt the current task with a newly woken task if needed: */ -static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int sync) +static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flags) { if (p->prio < rq->curr->prio) { resched_task(rq->curr); diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c index 55a25c933d1..3aaa77c3309 100644 --- a/kernel/trace/trace_event_profile.c +++ b/kernel/trace/trace_event_profile.c @@ -8,6 +8,54 @@ #include <linux/module.h> #include "trace.h" +/* + * We can't use a size but a type in alloc_percpu() + * So let's create a dummy type that matches the desired size + */ +typedef struct {char buf[FTRACE_MAX_PROFILE_SIZE];} profile_buf_t; + +char *trace_profile_buf; +char *trace_profile_buf_nmi; + +/* Count the events in use (per event id, not per instance) */ +static int total_profile_count; + +static int ftrace_profile_enable_event(struct ftrace_event_call *event) +{ + char *buf; + int ret = -ENOMEM; + + if (atomic_inc_return(&event->profile_count)) + return 0; + + if (!total_profile_count++) { + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf; + + rcu_assign_pointer(trace_profile_buf, buf); + + buf = (char *)alloc_percpu(profile_buf_t); + if (!buf) + goto fail_buf_nmi; + + rcu_assign_pointer(trace_profile_buf_nmi, buf); + } + + ret = event->profile_enable(); + if (!ret) + return 0; + + kfree(trace_profile_buf_nmi); +fail_buf_nmi: + kfree(trace_profile_buf); +fail_buf: + total_profile_count--; + atomic_dec(&event->profile_count); + + return ret; +} + int ftrace_profile_enable(int event_id) { struct ftrace_event_call *event; @@ -17,7 +65,7 @@ int ftrace_profile_enable(int event_id) list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id && event->profile_enable && try_module_get(event->mod)) { - ret = event->profile_enable(event); + ret = ftrace_profile_enable_event(event); break; } } @@ -26,6 +74,33 @@ int ftrace_profile_enable(int event_id) return ret; } +static void ftrace_profile_disable_event(struct ftrace_event_call *event) +{ + char *buf, *nmi_buf; + + if (!atomic_add_negative(-1, &event->profile_count)) + return; + + event->profile_disable(); + + if (!--total_profile_count) { + buf = trace_profile_buf; + rcu_assign_pointer(trace_profile_buf, NULL); + + nmi_buf = trace_profile_buf_nmi; + rcu_assign_pointer(trace_profile_buf_nmi, NULL); + + /* + * Ensure every events in profiling have finished before + * releasing the buffers + */ + synchronize_sched(); + + free_percpu(buf); + free_percpu(nmi_buf); + } +} + void ftrace_profile_disable(int event_id) { struct ftrace_event_call *event; @@ -33,7 +108,7 @@ void ftrace_profile_disable(int event_id) mutex_lock(&event_mutex); list_for_each_entry(event, &ftrace_events, list) { if (event->id == event_id) { - event->profile_disable(event); + ftrace_profile_disable_event(event); module_put(event->mod); break; } diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 687699d365a..2547d8813cf 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -11,7 +11,6 @@ #include <linux/ftrace.h> #include <linux/string.h> #include <linux/module.h> -#include <linux/marker.h> #include <linux/mutex.h> #include <linux/ctype.h> #include <linux/list.h> diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c index 8712ce3c6a0..7a3550cf259 100644 --- a/kernel/trace/trace_syscalls.c +++ b/kernel/trace/trace_syscalls.c @@ -384,10 +384,13 @@ static int sys_prof_refcount_exit; static void prof_syscall_enter(struct pt_regs *regs, long id) { - struct syscall_trace_enter *rec; struct syscall_metadata *sys_data; + struct syscall_trace_enter *rec; + unsigned long flags; + char *raw_data; int syscall_nr; int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_enter_syscalls)) @@ -402,20 +405,38 @@ static void prof_syscall_enter(struct pt_regs *regs, long id) size = ALIGN(size + sizeof(u32), sizeof(u64)); size -= sizeof(u32); - do { - char raw_data[size]; + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "profile buffer not large enough")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); - /* zero the dead bytes from align to not leak stack to user */ - *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; - rec = (struct syscall_trace_enter *) raw_data; - tracing_generic_entry_update(&rec->ent, 0, 0); - rec->ent.type = sys_data->enter_id; - rec->nr = syscall_nr; - syscall_get_arguments(current, regs, 0, sys_data->nb_args, - (unsigned long *)&rec->args); - perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); - } while(0); + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_enter *) raw_data; + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->enter_id; + rec->nr = syscall_nr; + syscall_get_arguments(current, regs, 0, sys_data->nb_args, + (unsigned long *)&rec->args); + perf_tpcounter_event(sys_data->enter_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_enter(char *name) @@ -460,8 +481,12 @@ void unreg_prof_syscall_enter(char *name) static void prof_syscall_exit(struct pt_regs *regs, long ret) { struct syscall_metadata *sys_data; - struct syscall_trace_exit rec; + struct syscall_trace_exit *rec; + unsigned long flags; int syscall_nr; + char *raw_data; + int size; + int cpu; syscall_nr = syscall_get_nr(current, regs); if (!test_bit(syscall_nr, enabled_prof_exit_syscalls)) @@ -471,12 +496,46 @@ static void prof_syscall_exit(struct pt_regs *regs, long ret) if (!sys_data) return; - tracing_generic_entry_update(&rec.ent, 0, 0); - rec.ent.type = sys_data->exit_id; - rec.nr = syscall_nr; - rec.ret = syscall_get_return_value(current, regs); + /* We can probably do that at build time */ + size = ALIGN(sizeof(*rec) + sizeof(u32), sizeof(u64)); + size -= sizeof(u32); - perf_tpcounter_event(sys_data->exit_id, 0, 1, &rec, sizeof(rec)); + /* + * Impossible, but be paranoid with the future + * How to put this check outside runtime? + */ + if (WARN_ONCE(size > FTRACE_MAX_PROFILE_SIZE, + "exit event has grown above profile buffer size")) + return; + + /* Protect the per cpu buffer, begin the rcu read side */ + local_irq_save(flags); + cpu = smp_processor_id(); + + if (in_nmi()) + raw_data = rcu_dereference(trace_profile_buf_nmi); + else + raw_data = rcu_dereference(trace_profile_buf); + + if (!raw_data) + goto end; + + raw_data = per_cpu_ptr(raw_data, cpu); + + /* zero the dead bytes from align to not leak stack to user */ + *(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL; + + rec = (struct syscall_trace_exit *)raw_data; + + tracing_generic_entry_update(&rec->ent, 0, 0); + rec->ent.type = sys_data->exit_id; + rec->nr = syscall_nr; + rec->ret = syscall_get_return_value(current, regs); + + perf_tpcounter_event(sys_data->exit_id, 0, 1, rec, size); + +end: + local_irq_restore(flags); } int reg_prof_syscall_exit(char *name) |