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2008-07-20initrd: Fix virtual/physical mix-up in overwrite testGeert Uytterhoeven
On recent kernels, I get the following error when using an initrd: | initrd overwritten (0x00b78000 < 0x07668000) - disabling it. My Amiga 4000 has 12 MiB of RAM at physical address 0x07400000 (virtual 0x00000000). The initrd is located at the end of RAM: 0x00b78000 - 0x00c00000 (virtual). The overwrite test compares the (virtual) initrd location to the (physical) first available memory location, which fails. This patch converts initrd_start to a page frame number, so it can safely be compared with min_low_pfn. Before the introduction of discontiguous memory support on m68k (12d810c1b8c2b913d48e629e2b5c01d105029839), min_low_pfn was just left untouched by the m68k-specific code (zero, I guess), and everything worked fine. Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-15Merge branch 'generic-ipi-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'generic-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits) generic-ipi: more merge fallout generic-ipi: merge fix x86, visws: use mach-default/entry_arch.h x86, visws: fix generic-ipi build generic-ipi: fixlet generic-ipi: fix s390 build bug generic-ipi: fix linux-next tree build failure fix: "smp_call_function: get rid of the unused nonatomic/retry argument" fix: "smp_call_function: get rid of the unused nonatomic/retry argument" fix "smp_call_function: get rid of the unused nonatomic/retry argument" on_each_cpu(): kill unused 'retry' parameter smp_call_function: get rid of the unused nonatomic/retry argument sh: convert to generic helpers for IPI function calls parisc: convert to generic helpers for IPI function calls mips: convert to generic helpers for IPI function calls m32r: convert to generic helpers for IPI function calls arm: convert to generic helpers for IPI function calls alpha: convert to generic helpers for IPI function calls ia64: convert to generic helpers for IPI function calls powerpc: convert to generic helpers for IPI function calls ... Fix trivial conflicts due to rcu updates in kernel/rcupdate.c manually
2008-06-26Add generic helpers for arch IPI function callsJens Axboe
This adds kernel/smp.c which contains helpers for IPI function calls. In addition to supporting the existing smp_call_function() in a more efficient manner, it also adds a more scalable variant called smp_call_function_single() for calling a given function on a single CPU only. The core of this is based on the x86-64 patch from Nick Piggin, lots of changes since then. "Alan D. Brunelle" <Alan.Brunelle@hp.com> has contributed lots of fixes and suggestions as well. Also thanks to Paul E. McKenney <paulmck@linux.vnet.ibm.com> for reviewing RCU usage and getting rid of the data allocation fallback deadlock. Acked-by: Ingo Molnar <mingo@elte.hu> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-05-19rcu: add call_rcu_sched()Paul E. McKenney
Fourth cut of patch to provide the call_rcu_sched(). This is again to synchronize_sched() as call_rcu() is to synchronize_rcu(). Should be fine for experimental and -rt use, but not ready for inclusion. With some luck, I will be able to tell Andrew to come out of hiding on the next round. Passes multi-day rcutorture sessions with concurrent CPU hotplugging. Fixes since the first version include a bug that could result in indefinite blocking (spotted by Gautham Shenoy), better resiliency against CPU-hotplug operations, and other minor fixes. Fixes since the second version include reworking grace-period detection to avoid deadlocks that could happen when running concurrently with CPU hotplug, adding Mathieu's fix to avoid the softlockup messages, as well as Mathieu's fix to allow use earlier in boot. Fixes since the third version include a wrong-CPU bug spotted by Andrew, getting rid of the obsolete synchronize_kernel API that somehow snuck back in, merging spin_unlock() and local_irq_restore() in a few places, commenting the code that checks for quiescent states based on interrupting from user-mode execution or the idle loop, removing some inline attributes, and some code-style changes. Known/suspected shortcomings: o I still do not entirely trust the sleep/wakeup logic. Next step will be to use a private snapshot of the CPU online mask in rcu_sched_grace_period() -- if the CPU wasn't there at the start of the grace period, we don't need to hear from it. And the bit about accounting for changes in online CPUs inside of rcu_sched_grace_period() is ugly anyway. o It might be good for rcu_sched_grace_period() to invoke resched_cpu() when a given CPU wasn't responding quickly, but resched_cpu() is declared static... This patch also fixes a long-standing bug in the earlier preemptable-RCU implementation of synchronize_rcu() that could result in loss of concurrent external changes to a task's CPU affinity mask. I still cannot remember who reported this... Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-15initcalls: Fix m68k build and possible buffer overflowCyrill Gorcunov
This patch fixes a build bug on m68k - gcc decides to emit a call to the strlen library function, which we don't implement. More importantly - my previous patch "init: don't lose initcall return values" (commit e662e1cfd434aa234b72fbc781f1d70211cb785b) had introduced potential buffer overflow by wrong calculation of string accumulator size. Use strlcat() instead, fixing both bugs. Many thanks Andreas Schwab and Geert Uytterhoeven for helping to catch and fix the bug. Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-15Split up 'do_initcalls()' into two simpler functionsLinus Torvalds
One function to just loop over the entries, one function to actually do the call and the associated debugging code. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-15Clean up 'print_fn_descriptor_symbol()' typesLinus Torvalds
Everybody wants to pass it a function pointer, and in fact, that is what you _must_ pass it for it to make sense (since it knows that ia64 and ppc64 use descriptors for function pointers and fetches the actual address from there). So don't make the argument be a 'unsigned long' and force everybody to add a cast. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13init: don't lose initcall return valuesCyrill Gorcunov
There is an ability to lose an initcall return value if it happened with irq disabled or imbalanced preemption (and if we debug initcall). Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-05sched: add optional support for CONFIG_HAVE_UNSTABLE_SCHED_CLOCKPeter Zijlstra
this replaces the rq->clock stuff (and possibly cpu_clock()). - architectures that have an 'imperfect' hardware clock can set CONFIG_HAVE_UNSTABLE_SCHED_CLOCK - the 'jiffie' window might be superfulous when we update tick_gtod before the __update_sched_clock() call in sched_clock_tick() - cpu_clock() might be implemented as: sched_clock_cpu(smp_processor_id()) if the accuracy proves good enough - how far can TSC drift in a single jiffie when considering the filtering and idle hooks? [ mingo@elte.hu: various fixes and cleanups ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-30infrastructure to debug (dynamic) objectsThomas Gleixner
We can see an ever repeating problem pattern with objects of any kind in the kernel: 1) freeing of active objects 2) reinitialization of active objects Both problems can be hard to debug because the crash happens at a point where we have no chance to decode the root cause anymore. One problem spot are kernel timers, where the detection of the problem often happens in interrupt context and usually causes the machine to panic. While working on a timer related bug report I had to hack specialized code into the timer subsystem to get a reasonable hint for the root cause. This debug hack was fine for temporary use, but far from a mergeable solution due to the intrusiveness into the timer code. The code further lacked the ability to detect and report the root cause instantly and keep the system operational. Keeping the system operational is important to get hold of the debug information without special debugging aids like serial consoles and special knowledge of the bug reporter. The problems described above are not restricted to timers, but timers tend to expose it usually in a full system crash. Other objects are less explosive, but the symptoms caused by such mistakes can be even harder to debug. Instead of creating specialized debugging code for the timer subsystem a generic infrastructure is created which allows developers to verify their code and provides an easy to enable debug facility for users in case of trouble. The debugobjects core code keeps track of operations on static and dynamic objects by inserting them into a hashed list and sanity checking them on object operations and provides additional checks whenever kernel memory is freed. The tracked object operations are: - initializing an object - adding an object to a subsystem list - deleting an object from a subsystem list Each operation is sanity checked before the operation is executed and the subsystem specific code can provide a fixup function which allows to prevent the damage of the operation. When the sanity check triggers a warning message and a stack trace is printed. The list of operations can be extended if the need arises. For now it's limited to the requirements of the first user (timers). The core code enqueues the objects into hash buckets. The hash index is generated from the address of the object to simplify the lookup for the check on kfree/vfree. Each bucket has it's own spinlock to avoid contention on a global lock. The debug code can be compiled in without being active. The runtime overhead is minimal and could be optimized by asm alternatives. A kernel command line option enables the debugging code. Thanks to Ingo Molnar for review, suggestions and cleanup patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Greg KH <greg@kroah.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30Deprecate find_task_by_pid()Pavel Emelyanov
There are some places that are known to operate on tasks' global pids only: * the rest_init() call (called on boot) * the kgdb's getthread * the create_kthread() (since the kthread is run in init ns) So use the find_task_by_pid_ns(..., &init_pid_ns) there and schedule the find_task_by_pid for removal. [sukadev@us.ibm.com: Fix warning in kernel/pid.c] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: fix /sbin/init protection from unwanted signalsOleg Nesterov
The global init has a lot of long standing problems with the unhandled fatal signals. - The "is_global_init(current)" check in get_signal_to_deliver() protects only the main thread. Sub-thread can dequee the fatal signal and shutdown the whole thread group except the main thread. If it dequeues SIGSTOP /sbin/init will be stopped, this is not right too. Note that we can't use is_global_init(->group_leader), this breaks exec and this can't solve other problems we have. - Even if afterwards ignored, the fatal signals sets SIGNAL_GROUP_EXIT on delivery. This breaks exec, has other bad implications, and this is just wrong. Introduce the new SIGNAL_UNKILLABLE flag to fix these problems. It also helps to solve some other problems addressed by the subsequent patches. Currently we use this flag for the global init only, but it could also be used by kthreads and (perhaps) by the sub-namespace inits. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29idr: create idr_layer_cache at boot timeAkinobu Mita
Avoid a possible kmem_cache_create() failure by creating idr_layer_cache unconditionary at boot time rather than creating it on-demand when idr_init() is called the first time. This change also enables us to eliminate the check every time idr_init() is called. [akpm@linux-foundation.org: rename init_id_cache() to idr_init_cache()] [akpm@linux-foundation.org: fix alpha build] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29cgroups: add an owner to the mm_structBalbir Singh
Remove the mem_cgroup member from mm_struct and instead adds an owner. This approach was suggested by Paul Menage. The advantage of this approach is that, once the mm->owner is known, using the subsystem id, the cgroup can be determined. It also allows several control groups that are virtually grouped by mm_struct, to exist independent of the memory controller i.e., without adding mem_cgroup's for each controller, to mm_struct. A new config option CONFIG_MM_OWNER is added and the memory resource controller selects this config option. This patch also adds cgroup callbacks to notify subsystems when mm->owner changes. The mm_cgroup_changed callback is called with the task_lock() of the new task held and is called just prior to changing the mm->owner. I am indebted to Paul Menage for the several reviews of this patchset and helping me make it lighter and simpler. This patch was tested on a powerpc box, it was compiled with both the MM_OWNER config turned on and off. After the thread group leader exits, it's moved to init_css_state by cgroup_exit(), thus all future charges from runnings threads would be redirected to the init_css_set's subsystem. Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Hirokazu Takahashi <taka@valinux.co.jp> Cc: David Rientjes <rientjes@google.com>, Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Reviewed-by: Paul Menage <menage@google.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29Simplify initcall_debug outputBjorn Helgaas
print_fn_descriptor_symbol() prints the address if we don't have a symbol, so no need to print both. Also, combine printing return value with elapsed time. Changes this: Calling initcall 0xc05b7a70: pci_mmcfg_late_insert_resources+0x0/0x50() initcall 0xc05b7a70: pci_mmcfg_late_insert_resources+0x0/0x50() returned 1. initcall 0xc05b7a70 ran for 0 msecs: pci_mmcfg_late_insert_resources+0x0/0x50() initcall at 0xc05b7a70: pci_mmcfg_late_insert_resources+0x0/0x50(): returned with error code 1 to this: calling pci_mmcfg_late_insert_resources+0x0/0x50() initcall pci_mmcfg_late_insert_resources+0x0/0x50() returned 1 after 0 msecs initcall pci_mmcfg_late_insert_resources+0x0/0x50() returned with error code 1 Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-24[POWERPC] Use __weak macro for smp_setup_processor_idBenjamin Herrenschmidt
Use the __weak macro instead of the longer __attribute__ ((weak)) form in one place in init/main.c. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> -- init/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24[POWERPC] Add thread_info_cache_init() weak hookBenjamin Herrenschmidt
Some architectures need to maintain a kmem cache for thread info structures. The next commit adds that to powerpc to fix an alignment problem. There is no good arch callback to use to initialize that cache that I can find, so this adds a new one in the form of a weak function whose default is empty. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-19init: move setup of nr_cpu_ids to as early as possibleMike Travis
Move the setting of nr_cpu_ids from sched_init() to start_kernel() so that it's available as early as possible. Note that an arch has the option of setting it even earlier if need be, but it should not result in a different value than the setup_nr_cpu_ids() function. Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-19cpumask: add CPU_MASK_ALL_PTR macroMike Travis
* Add a static cpumask_t variable "CPU_MASK_ALL_PTR" to use as a pointer reference to CPU_MASK_ALL. This reduces where possible the instances where CPU_MASK_ALL allocates and fills a large array on the stack. Used only if NR_CPUS > BITS_PER_LONG. * Change init/main.c to use new set_cpus_allowed_ptr(). Depends on: [sched-devel]: sched: add new set_cpus_allowed_ptr function Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-03-15ACPI: Remove ACPI_CUSTOM_DSDT_INITRD optionLinus Torvalds
This essentially reverts commit 71fc47a9adf8ee89e5c96a47222915c5485ac437 ("ACPI: basic initramfs DSDT override support"), because the code simply isn't ready. It did ugly things to the init sequence to populate the rootfs image early, but that just ended up showing other problems with the whole approach. The fact is, the VFS layer simply isn't initialized this early, and the relevant ACPI code should either run much later, or this shouldn't be done at all. For 2.6.25, we'll just pick the latter option. We can revisit this concept later if necessary. Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Tilman Schmidt <tilman@imap.cc> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Renninger <trenn@suse.de> Cc: Eric Piel <eric.piel@tremplin-utc.net> Cc: Len Brown <len.brown@intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Markus Gaugusch <dsdt@gaugusch.at> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04Fix "Malformed early option 'loglevel'"Alex Riesen
Keith Mannthey said: The parameter hotadd_percent is setup right but there is a "Malformed early option 'numa'" message. Rusty Russell said: This happens when the function registered with early_param() returns non-zero. __setup() functions return 1 if OK, module_param() and early_param() return 0 or a -ve error code. For instance: Linux version 2.6.25-rc3-t (raa@steel) (gcc version 4.1.3 20070929 (prerelease) (Ubuntu 4.1.2-16ubuntu2)) #22 SMP PREEMPT Tue Feb 26 BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 00000000000a0000 (usable) BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 000000003fff0000 (usable) BIOS-e820: 000000003fff0000 - 000000003fff3000 (ACPI NVS) BIOS-e820: 000000003fff3000 - 0000000040000000 (ACPI data) BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved) Malformed early option 'loglevel' 127MB HIGHMEM available. 896MB LOWMEM available. Command line: BOOT_IMAGE=2.6.25-t ro root=809 ro console=ttyS0,57600n8 console=tty0 loglevel=5 Acked-by: Yinghai Lu <yhlu.kernel@gmai.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Keith Mannthey <kmannth@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-09x86: DEBUG_PAGEALLOC: enable after mem_init()Thomas Gleixner
DEBUG_PAGEALLOC must not be enabled before mem_init(). Before this point there is nothing to allocate. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-08Convert loglevel-related kernel boot parameters to early_paramYinghai Lu
So we can use them for the early console like console=uart8250 or earlycon=uart8250 or early_printk Signed-off-by: Yinghai Lu <yinghai.lu@sun.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08start the global /sbin/init with 0,0 special pidsOleg Nesterov
As Eric pointed out, there is no problem with init starting with sid == pgid == 0, and this was historical linux behavior changed in 2.6.18. Remove kernel_init()->__set_special_pids(), this is unneeded and complicates the rules for sys_setsid(). This change and the previous change in daemonize() mean that /sbin/init does not need the special "session != 1" hack in sys_setsid() any longer. We can't remove this check yet, we should cleanup copy_process(CLONE_NEWPID) first, so update the comment only. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08teach set_special_pids() to use struct pidOleg Nesterov
Change set_special_pids() to work with struct pid, not pid_t from global name space. This again speedups and imho cleanups the code, also a preparation for the next patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-06ACPI: basic initramfs DSDT override supportMarkus Gaugusch
The basics of DSDT from initramfs. In case this option is selected, populate_rootfs() is called a bit earlier to have the initramfs content available during ACPI initialization. This is a very similar path to the one available at http://gaugusch.at/kernel.shtml but with some update in the documentation, default set to No and the change of populate_rootfs() the "Jeff Mahony way" (which avoids reading the initramfs twice). Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Eric Piel <eric.piel@tremplin-utc.net> Signed-off-by: Len Brown <len.brown@intel.com>
2008-02-06proper prototype for signals_init()Adrian Bunk
Add a proper prototype for signals_init() in include/linux/signal.h Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-30x86: do not PSE on CONFIG_DEBUG_PAGEALLOC=yIngo Molnar
get more testing of the c_p_a() code done by not turning off PSE on DEBUG_PAGEALLOC. this simplifies the early pagetable setup code, and tests the largepage-splitup code quite heavily. In the end, all the largepages will be split up pretty quickly, so there's no difference to how DEBUG_PAGEALLOC worked before. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86/non-x86: percpu, node ids, apic ids x86.git fixupMike Travis
Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: optimize lock prefix switching to run less frequentlyAndi Kleen
On VMs implemented using JITs that cache translated code changing the lock prefixes is a quite costly operation that forces the JIT to throw away and retranslate a lot of code. Previously a SMP kernel would rewrite the locks once for each CPU which is quite unnecessary. This patch changes the code to never switch at boot in the normal case (SMP kernel booting with >1 CPU) or only once for SMP kernel on UP. This makes a significant difference in boot up performance on AMD SimNow! Also I expect it to be a little faster on native systems too because a smp switch does a lot of text_poke()s which each synchronize the pipeline. v1->v2: Rename max_cpus v1->v2: Fix off by one in UP check (Thomas Gleixner) Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30percpu: use a kconfig variable to signal arch specific percpu setuptravis@sgi.com
The use of the __GENERIC_PERCPU is a bit problematic since arches may want to run their own percpu setup while using the generic percpu definitions. Replace it through a kconfig variable. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Mike Travis <travis@sgi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-01-25cpu-hotplug: refcount based cpu hotplugGautham R Shenoy
This patch implements a Refcount + Waitqueue based model for cpu-hotplug. Now, a thread which wants to prevent cpu-hotplug, will bump up a global refcount and the thread which wants to perform a cpu-hotplug operation will block till the global refcount goes to zero. The readers, if any, during an ongoing cpu-hotplug operation are blocked until the cpu-hotplug operation is over. Signed-off-by: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Paul Jackson <pj@sgi.com> [For !CONFIG_HOTPLUG_CPU ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-11-09sched: proper prototype for kernel/sched.c:migration_init()Adrian Bunk
This patch adds a proper prototype for migration_init() in include/linux/sched.h Since there's no point in always returning 0 to a caller that doesn't check the return value it also changes the function to return void. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-10-20spelling fixes: init/Simon Arlott
Spelling fix in init/. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19Drop the superfluous test for an old version of gcc.Robert P. J. Day
The header file <linux/compiler.h> already enforces a suitably recent version of gcc, so there's no point checking for that again. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19Task Control Groups: basic task cgroup frameworkPaul Menage
Generic Process Control Groups -------------------------- There have recently been various proposals floating around for resource management/accounting and other task grouping subsystems in the kernel, including ResGroups, User BeanCounters, NSProxy cgroups, and others. These all need the basic abstraction of being able to group together multiple processes in an aggregate, in order to track/limit the resources permitted to those processes, or control other behaviour of the processes, and all implement this grouping in different ways. This patchset provides a framework for tracking and grouping processes into arbitrary "cgroups" and assigning arbitrary state to those groupings, in order to control the behaviour of the cgroup as an aggregate. The intention is that the various resource management and virtualization/cgroup efforts can also become task cgroup clients, with the result that: - the userspace APIs are (somewhat) normalised - it's easier to test e.g. the ResGroups CPU controller in conjunction with the BeanCounters memory controller, or use either of them as the resource-control portion of a virtual server system. - the additional kernel footprint of any of the competing resource management systems is substantially reduced, since it doesn't need to provide process grouping/containment, hence improving their chances of getting into the kernel This patch: Add the main task cgroups framework - the cgroup filesystem, and the basic structures for tracking membership and associating subsystem state objects to tasks. Signed-off-by: Paul Menage <menage@google.com> Cc: Serge E. Hallyn <serue@us.ibm.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-30fix maxcpus=1 oops in show_stat()Hugh Dickins
Alexey Dobriyan reports that maxcpus=1 is still broken in 2.6.23-rc4: if CONFIG_HOTPLUG_CPU is not set, x86_64 bootup oopses in show_stat() - for_each_possible_cpu accesses a per-cpu area which was never set up. Alexey identified commit 61ec7567db103d537329b0db9a887db570431ff4 (ACPI: boot correctly with "nosmp" or "maxcpus=0") as the origin; but it's not really to blame, just exposes a bug in 2.6.23-rc1's commit 8b3b295502444340dd0701855ac422fbf32e161d (Especially when !CONFIG_HOTPLUG_CPU, avoid needlessy allocating resources for CPUs that can never become available). rc1's test for max_cpus < 2 in start_kernel() wasn't working because max_cpus was still NR_CPUS at that point: until rc4 moved the maxcpus parsing earlier. Now it sets cpu_possible_map to 1 before allocating all possible per-cpu areas; then smp_init() expands cpu_possible_map to cpu_present_map (0xf in my case) later on. rc1's commit has good intentions, but expects cpu_present_map to be limited by maxcpus, which is only the case on i386. cpus_and(possible, possible,present) might be good, but needs an audit of cpu_present_map uses - there may well be assumptions that any cpu present is possible. So stay safe for now and just revert those #ifndef CONFIG_HOTPLUG_CPU optimizations in rc1's commit. Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Len Brown <lenb@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-27fix maxcpus=N parsingHugh Dickins
Commit 61ec7567db103d537329b0db9a887db570431ff4 ('ACPI: boot correctly with "nosmp" or "maxcpus=0"') broke 'maxcpus=' handling on x86[-64]. maxcpus=N is now having no effect on x86_64, and freezing bootup on i386 (because of inconsistency with the separate maxcpus parsing down in arch/i386, I guess). That's because early_param parsing is a little different from __setup parsing, and needs the "=" omitted: then it seems to work as the original commit intended (no mention of IO-APIC in /proc/interrupts when maxcpus=0). Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Len Brown <len.brown@intel.com> Cc: Andi Kleen <ak@suse.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-21ACPI: boot correctly with "nosmp" or "maxcpus=0"Len Brown
In MPS mode, "nosmp" and "maxcpus=0" boot a UP kernel with IOAPIC disabled. However, in ACPI mode, these parameters didn't completely disable the IO APIC initialization code and boot failed. init/main.c: Disable the IO_APIC if "nosmp" or "maxcpus=0" undefine disable_ioapic_setup() when it doesn't apply. i386: delete ioapic_setup(), it was a duplicate of parse_noapic() delete undefinition of disable_ioapic_setup() x86_64: rename disable_ioapic_setup() to parse_noapic() to match i386 define disable_ioapic_setup() in header to match i386 http://bugzilla.kernel.org/show_bug.cgi?id=1641 Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Len Brown <len.brown@intel.com>
2007-07-16adjust nosmp handlingJan Beulich
Especially when !CONFIG_HOTPLUG_CPU, avoid needlessy allocating resources for CPUs that can never become available. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16Allow softlockup to be runtime disabledDave Jones
It's useful sometimes to disable the softlockup checker at boottime. Especially if it triggers during a distro install. Signed-off-by: Dave Jones <davej@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16serial: convert early_uart to earlycon for 8250Yinghai Lu
Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in serial initializing stage. the console_init=>serial8250_console_init=> register_console=>serial8250_console_setup will return -ENDEV, and console ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in drivers/serial/serial_core.c to call register_console to get console ttyS0. that is too late. Make early_uart to use early_param, so uart console can be used earlier. Make it to be bootconsole with CON_BOOT flag, so can use console handover feature. and it will switch to corresponding normal serial console automatically. new command line will be: console=uart8250,io,0x3f8,9600n8 console=uart8250,mmio,0xff5e0000,115200n8 or earlycon=uart8250,io,0x3f8,9600n8 earlycon=uart8250,mmio,0xff5e0000,115200n8 it will print in very early stage: Early serial console at I/O port 0x3f8 (options '9600n8') console [uart0] enabled later for console it will print: console handover: boot [uart0] -> real [ttyS0] Signed-off-by: <yinghai.lu@sun.com> Cc: Andi Kleen <ak@suse.de> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-09sched: add init_idle_bootup_task()Ingo Molnar
add the init_idle_bootup_task() callback to the bootup thread, unused at the moment. (CFS will use it to switch the scheduling class of the boot thread to the idle class) Signed-off-by: Ingo Molnar <mingo@elte.hu>
2007-05-19init/main: use __init_refok to fix section mismatchSam Ravnborg
Kill a special case in modpost by introducing the __init_refok marker. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2007-05-11Explicitly set pgid and sid of init processSukadev Bhattiprolu
Explicitly set pgid and sid of init process to 1. Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: <containers@lists.osdl.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09kthread: don't depend on work queuesEric W. Biederman
Currently there is a circular reference between work queue initialization and kthread initialization. This prevents the kthread infrastructure from initializing until after work queues have been initialized. We want the properties of tasks created with kthread_create to be as close as possible to the init_task and to not be contaminated by user processes. The later we start our kthreadd that creates these tasks the harder it is to avoid contamination from user processes and the more of a mess we have to clean up because the defaults have changed on us. So this patch modifies the kthread support to not use work queues but to instead use a simple list of structures, and to have kthreadd start from init_task immediately after our kernel thread that execs /sbin/init. By being a true child of init_task we only have to change those process settings that we want to have different from init_task, such as our process name, the cpus that are allowed, blocking all signals and setting SIGCHLD to SIG_IGN so that all of our children are reaped automatically. By being a true child of init_task we also naturally get our ppid set to 0 and do not wind up as a child of PID == 1. Ensuring that tasks generated by kthread_create will not slow down the functioning of the wait family of functions. [akpm@linux-foundation.org: use interruptible sleeps] Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08enhance initcall_debug, measure latencyIngo Molnar
enhance the initcall_debug boot option: - measure the time the initcall took to execute and report it in units of milliseconds. - show the return code of initcalls (useful to see failures and to make sure that an initcall hung) [akpm@linux-foundation.org: fix printk warning] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08init/do_mounts.c: proper prepare_namespace() prototypeAdrian Bunk
Add a proper protype for prepare_namespace() in include/linux/init.h. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07Safer nr_node_ids and nr_node_ids determination and initial valuesChristoph Lameter
The nr_cpu_ids value is currently only calculated in smp_init. However, it may be needed before (SLUB needs it on kmem_cache_init!) and other kernel components may also want to allocate dynamically sized per cpu array before smp_init. So move the determination of possible cpus into sched_init() where we already loop over all possible cpus early in boot. Also initialize both nr_node_ids and nr_cpu_ids with the highest value they could take. If we have accidental users before these values are determined then the current valud of 0 may cause too small per cpu and per node arrays to be allocated. If it is set to the maximum possible then we only waste some memory for early boot users. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuildLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (38 commits) kconfig: fix mconf segmentation fault kbuild: enable use of code from a different dir kconfig: error out if recursive dependencies are found kbuild: scripts/basic/fixdep segfault on pathological string-o-death kconfig: correct minor typo in Kconfig warning message. kconfig: fix path to modules.txt in Kconfig help usr/Kconfig: fix typo kernel-doc: alphabetically-sorted entries in index.html of 'htmldocs' kbuild: be more explicit on missing .config file kbuild: clarify the creation of the LOCALVERSION_AUTO string. kbuild: propagate errors from find in scripts/gen_initramfs_list.sh kconfig: refer to qt3 if we cannot find qt libraries kbuild: handle compressed cpio initramfs-es kbuild: ignore section mismatch warning for references from .paravirtprobe to .init.text kbuild: remove stale comment in modpost.c kbuild/mkuboot.sh: allow spaces in CROSS_COMPILE kbuild: fix make mrproper for Documentation/DocBook/man kbuild: remove kconfig binaries during make mrproper kconfig/menuconfig: do not hardcode '.config' kbuild: override build timestamp & version ...