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2008-10-16sysctl: simplify ->strategyAlexey Dobriyan
name and nlen parameters passed to ->strategy hook are unused, remove them. In general ->strategy hook should know what it's doing, and don't do something tricky for which, say, pointer to original userspace array may be needed (name). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ] Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16compat: generic compat get/settimeofdayChristoph Hellwig
Nothing arch specific in get/settimeofday. The details of the timeval conversion varied a little from arch to arch, but all with the same results. Also add an extern declaration for sys_tz to linux/time.h because externs in .c files are fowned upon. I'll kill the externs in various other files in a sparate patch. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: David S. Miller <davem@davemloft.net> [ sparc bits ] Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Acked-by: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16Add kerneldoc documentation for new printk format extensionsAndi Kleen
Add documentation in kerneldoc for new printk format extensions This patch documents the new %pS/%pF options in printk in kernel doc. Hope I didn't miss any other extension. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16taint: fix kernel-docRandy Dunlap
Move print_tainted() kernel-doc to avoid the following error: Error(/var/linsrc/mmotm-2008-1002-1617//kernel/panic.c:155): cannot understand prototype: 'struct tnt ' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16Remove Andrew Morton's old email accountsFrancois Cami
People can use the real name an an index into MAINTAINERS to find the current email address. Signed-off-by: Francois Cami <francois.cami@free.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16kernel/kallsyms.c: fix double returnWANG Cong
Commit 6dd06c9fbe025f542bce4cdb91790c0f91962722 ("module: make module_address_lookup safe") introduced double returns in the function kallsyms_lookup(), it's weird. The second one should be removed. Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16kernel/sys.c: improve code generationAndrew Morton
utsname() is quite expensive to calculate. Cache it in a local. text data bss dec hex filename before: 11136 720 16 11872 2e60 kernel/sys.o after: 11096 720 16 11832 2e38 kernel/sys.o Acked-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: "Serge E. Hallyn" <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16utsname: completely overwrite prior informationVegard Nossum
On sethostname() and setdomainname(), previous information may be retained if it was longer than than the new hostname/domainname. This can be demonstrated trivially by calling sethostname() first with a long name, then with a short name, and then calling uname() to retrieve the full buffer that contains the hostname (and possibly parts of the old hostname), one just has to look past the terminating zero. I don't know if we should really care that much (hence the RFC); the only scenarios I can possibly think of is administrator putting something sensitive in the hostname (or domain name) by accident, and changing it back will not undo the mistake entirely, though it's not like we can recover gracefully from "rm -rf /" either... The other scenario is namespaces (CLONE_NEWUTS) where some information may be unintentionally "inherited" from the previous namespace (a program wants to hide the original name and does clone + sethostname, but some information is still left). I think the patch may be defended on grounds of the principle of least surprise. But I am not adamant :-) (I guess the question now is whether userspace should be able to write embedded NULs into the buffer or not...) At least the observation has been made and the patch has been presented. Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Serge E. Hallyn" <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16profiling: dynamically enable readprofile at runtimeDave Hansen
Way too often, I have a machine that exhibits some kind of crappy behavior. The CPU looks wedged in the kernel or it is spending way too much system time and I wonder what is responsible. I try to run readprofile. But, of course, Ubuntu doesn't enable it by default. Dang! The reason we boot-time enable it is that it takes a big bufffer that we generally can only bootmem alloc. But, does it hurt to at least try and runtime-alloc it? To use: echo 2 > /sys/kernel/profile Then run readprofile like normal. This should fix the compile issue with allmodconfig. I've compile-tested on a bunch more configs now including a few more architectures. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16rlimit: permit setting RLIMIT_NOFILE to RLIM_INFINITYAdam Tkac
When a process wants to set the limit of open files to RLIM_INFINITY it gets EPERM even if it has CAP_SYS_RESOURCE capability. For example, BIND does: ... #elif defined(NR_OPEN) && defined(__linux__) /* * Some Linux kernels don't accept RLIM_INFINIT; the maximum * possible value is the NR_OPEN defined in linux/fs.h. */ if (resource == isc_resource_openfiles && rlim_value == RLIM_INFINITY) { rl.rlim_cur = rl.rlim_max = NR_OPEN; unixresult = setrlimit(unixresource, &rl); if (unixresult == 0) return (ISC_R_SUCCESS); } #elif ... If we allow setting RLIMIT_NOFILE to RLIM_INFINITY we increase portability - you don't have to check if OS is linux and then use different schema for limits. The spec says "Specifying RLIM_INFINITY as any resource limit value on a successful call to setrlimit() shall inhibit enforcement of that resource limit." and we're presently not doing that. Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16Make the taint flags reliableAndi Kleen
It's somewhat unlikely that it happens, but right now a race window between interrupts or machine checks or oopses could corrupt the tainted bitmap because it is modified in a non atomic fashion. Convert the taint variable to an unsigned long and use only atomic bit operations on it. Unfortunately this means the intvec sysctl functions cannot be used on it anymore. It turned out the taint sysctl handler could actually be simplified a bit (since it only increases capabilities) so this patch actually removes code. [akpm@linux-foundation.org: remove unneeded include] Signed-off-by: Andi Kleen <ak@linux.intel.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>
2008-10-16Kconfig: eliminate "def_bool n" constructsJan Beulich
Using "def_bool n" is pointless, simply using bool here appears more appropriate. Further, retaining such options that don't have a prompt and aren't selected by anything seems also at least questionable. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tony Luck <tony.luck@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16wait: kill is_sync_wait()Tejun Heo
is_sync_wait() is used to distinguish between sync and async waits. Basically sync waits are the ones initialized with init_waitqueue_entry() and async ones with init_waitqueue_func_entry(). The sync/async distinction is used only in prepare_to_wait[_exclusive]() and its only function is to skip setting the current task state if the wait is async. This has a few problems. * No one uses it. None of func_entry users use prepare_to_wait() functions, so the code path never gets executed. * The distinction is bogus. Maybe back when func_entry is used only by aio but it's now also used by epoll and in future possibly by 9p and poll/select. * Taking @state as argument and ignoring it silenly depending on how @wait is initialized is just a bad error-prone API. * It prevents func_entry waits from using wait->private for no good reason. This patch kills is_sync_wait() and the associated code paths from prepare_to_wait[_exclusive](). As there was no user of these code paths, this patch doesn't cause any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16kernel/dma.c: remove a CVS keywordAdrian Bunk
Remove a CVS keyword that wasn't updated for a long time from a comment. 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>
2008-10-16pm: rework disabling of user mode helpers during suspend/hibernationRafael J. Wysocki
We currently use a PM notifier to disable user mode helpers before suspend and hibernation and to re-enable them during resume. However, this is not an ideal solution, because if any drivers want to upload firmware into memory before suspend, they have to use a PM notifier for this purpose and there is no guarantee that the ordering of PM notifiers will be as expected (ie. the notifier that disables user mode helpers has to be run after the driver's notifier used for uploading the firmware). For this reason, it seems better to move the disabling and enabling of user mode helpers to separate functions that will be called by the PM core as necessary. [akpm@linux-foundation.org: remove unneeded ifdefs] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Alan Stern <stern@rowland.harvard.edu> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16memrlimit: cgroup mm owner callback changes to add task infoBalbir Singh
This patch adds an additional field to the mm_owner callbacks. This field is required to get to the mm that changed. Hold mmap_sem in write mode before calling the mm_owner_changed callback [hugh@veritas.com: fix mmap_sem deadlock] Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com> Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-14Merge branch 'for-2.6.28' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux: (59 commits) svcrdma: Fix IRD/ORD polarity svcrdma: Update svc_rdma_send_error to use DMA LKEY svcrdma: Modify the RPC reply path to use FRMR when available svcrdma: Modify the RPC recv path to use FRMR when available svcrdma: Add support to svc_rdma_send to handle chained WR svcrdma: Modify post recv path to use local dma key svcrdma: Add a service to register a Fast Reg MR with the device svcrdma: Query device for Fast Reg support during connection setup svcrdma: Add FRMR get/put services NLM: Remove unused argument from svc_addsock() function NLM: Remove "proto" argument from lockd_up() NLM: Always start both UDP and TCP listeners lockd: Remove unused fields in the nlm_reboot structure lockd: Add helper to sanity check incoming NOTIFY requests lockd: change nlmclnt_grant() to take a "struct sockaddr *" lockd: Adjust nlmsvc_lookup_host() to accomodate AF_INET6 addresses lockd: Adjust nlmclnt_lookup_host() signature to accomodate non-AF_INET lockd: Support non-AF_INET addresses in nlm_lookup_host() NLM: Convert nlm_lookup_host() to use a single argument svcrdma: Add Fast Reg MR Data Types ...
2008-10-13Merge branch 'proc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc * 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc: proc: remove kernel.maps_protect proc: remove now unneeded ADDBUF macro [PATCH] proc: show personality via /proc/pid/personality [PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock() proc: move PROC_PAGE_MONITOR to fs/proc/Kconfig proc: make grab_header() static proc: remove unused get_dma_list() proc: remove dummy vmcore_open() proc: proc_sys_root tweak proc: fix return value of proc_reg_open() in "too late" case Fixed up trivial conflict in removed file arch/sparc/include/asm/dma_32.h
2008-10-13tty: Fix abusers of current->sighand->ttyAlan Cox
Various people outside the tty layer still stick their noses in behind the scenes. We need to make sure they also obey the locking and referencing rules. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: Move tty_write_message out of kernel/printkAlan Cox
This is pure tty code so put it in the tty layer where it can be with the locking relevant material it uses Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13tty: Add a kref countAlan Cox
Introduce a kref to the tty structure and use it to protect the tty->signal tty references. For now we don't introduce it for anything else. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-11Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: sound/core/memalloc.c
2008-10-11Merge phase #4 (X2APIC, APIC unification, CPU identification unification) of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-v28-for-linus-phase4-D' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (186 commits) x86, debug: print more information about unknown CPUs x86 setup: handle more than 8 CPU flag words x86: cpuid, fix typo x86: move transmeta cap read to early_init_transmeta() x86: identify_cpu_without_cpuid v2 x86: extended "flags" to show virtualization HW feature in /proc/cpuinfo x86: move VMX MSRs to msr-index.h x86: centaur_64.c remove duplicated setting of CONSTANT_TSC x86: intel.c put workaround for old cpus together x86: let intel 64-bit use intel.c x86: make intel_64.c the same as intel.c x86: make intel.c have 64-bit support code x86: little clean up of intel.c/intel_64.c x86: make 64 bit to use amd.c x86: make amd_64 have 32 bit code x86: make amd.c have 64bit support code x86: merge header in amd_64.c x86: add srat_detect_node for amd64 x86: remove duplicated force_mwait x86: cpu make amd.c more like amd_64.c v2 ...
2008-10-11Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-DIngo Molnar
Conflicts: arch/x86/kernel/cpu/common.c arch/x86/kernel/signal_64.c include/asm-x86/cpufeature.h
2008-10-11Merge branch 'x86/apic' into x86-v28-for-linus-phase4-BIngo Molnar
Conflicts: arch/x86/kernel/apic_32.c arch/x86/kernel/apic_64.c arch/x86/kernel/setup.c drivers/pci/intel-iommu.c include/asm-x86/cpufeature.h include/asm-x86/dma-mapping.h
2008-10-11Merge phase #3 (IOMMU) of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-v28-for-linus-phase3-B' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits) AMD IOMMU: use iommu_device_max_index, fix AMD IOMMU: use iommu_device_max_index x86: add PCI IDs for AMD Barcelona PCI devices x86/iommu: use __GFP_ZERO instead of memset for GART x86/iommu: convert GART need_flush to bool x86/iommu: make GART driver checkpatch clean x86 gart: remove unnecessary initialization x86: restore old GART alloc_coherent behavior revert "x86: make GART to respect device's dma_mask about virtual mappings" x86: export pci-nommu's alloc_coherent iommu: remove fullflush and nofullflush in IOMMU generic option x86: remove set_bit_string() iommu: export iommu_area_reserve helper function AMD IOMMU: use coherent_dma_mask in alloc_coherent add AMD IOMMU tree to MAINTAINERS file AMD IOMMU: use cmd_buf_size when freeing the command buffer AMD IOMMU: calculate IVHD size with a function AMD IOMMU: remove unnecessary cast to u64 in the init code AMD IOMMU: free domain bitmap with its allocation order AMD IOMMU: simplify dma_mask_to_pages ...
2008-10-11Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Fix BUG: using smp_processor_id() in preemptible code [CPUFREQ] Don't export governors for default governor [CPUFREQ][6/6] cpufreq: Add idle microaccounting in ondemand governor [CPUFREQ][5/6] cpufreq: Changes to get_cpu_idle_time_us(), used by ondemand governor [CPUFREQ][4/6] cpufreq_ondemand: Parameterize down differential [CPUFREQ][3/6] cpufreq: get_cpu_idle_time() changes in ondemand for idle-microaccounting [CPUFREQ][2/6] cpufreq: Change load calculation in ondemand for software coordination [CPUFREQ][1/6] cpufreq: Add cpu number parameter to __cpufreq_driver_getavg() [CPUFREQ] use deferrable delayed work init in conservative governor [CPUFREQ] drivers/cpufreq/cpufreq.c: Adjust error handling code involving cpufreq_cpu_put [CPUFREQ] add error handling for cpufreq_register_governor() error [CPUFREQ] acpi-cpufreq: add error handling for cpufreq_register_driver() error [CPUFREQ] Coding style fixes to arch/x86/kernel/cpu/cpufreq/powernow-k6.c [CPUFREQ] Coding style fixes to arch/x86/kernel/cpu/cpufreq/elanfreq.c
2008-10-10Merge branch 'rcu-v28-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'rcu-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits) rcu: RCU-based detection of stalled CPUs for Classic RCU, fix rcu: RCU-based detection of stalled CPUs for Classic RCU rcu: add rcu_read_lock_sched() / rcu_read_unlock_sched() rcu: fix sparse shadowed variable warning doc/RCU: fix pseudocode in rcuref.txt rcuclassic: fix compiler warning rcu: use irq-safe locks rcuclassic: fix compilation NG rcu: fix locking cleanup fallout rcu: remove redundant ACCESS_ONCE definition from rcupreempt.c rcu: fix classic RCU locking cleanup lockdep problem rcu: trace fix possible mem-leak rcu: just rename call_rcu_bh instead of making it a macro rcu: remove list_for_each_rcu() rcu: fixes to include/linux/rcupreempt.h rcu: classic RCU locking and memory-barrier cleanups rcu: prevent console flood when one CPU sees another AWOL via RCU rcu, debug: detect stalled grace periods, cleanups rcu, debug: detect stalled grace periods rcu classic: new algorithm for callbacks-processing(v2) ...
2008-10-10Merge branches 'core/iommu', 'x86/amd-iommu' and 'x86/iommu' into ↵Ingo Molnar
x86-v28-for-linus-phase3-B Conflicts: arch/x86/kernel/pci-gart_64.c include/asm-x86/dma-mapping.h
2008-10-10proc: remove kernel.maps_protectAlexey Dobriyan
After commit 831830b5a2b5d413407adf380ef62fe17d6fcbf2 aka "restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace" sysctl stopped being relevant because commit moved security checks from ->show time to ->start time (mm_for_maps()). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Kees Cook <kees.cook@canonical.com>
2008-10-10[PATCH] signal, procfs: some lock_task_sighand() users do not need ↵Lai Jiangshan
rcu_read_lock() lock_task_sighand() make sure task->sighand is being protected, so we do not need rcu_read_lock(). [ exec() will get task->sighand->siglock before change task->sighand! ] But code using rcu_read_lock() _just_ to protect lock_task_sighand() only appear in procfs. (and some code in procfs use lock_task_sighand() without such redundant protection.) Other subsystem may put lock_task_sighand() into rcu_read_lock() critical region, but these rcu_read_lock() are used for protecting "for_each_process()", "find_task_by_vpid()" etc. , not for protecting lock_task_sighand(). Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> [ok from Oleg] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2008-10-09[CPUFREQ][5/6] cpufreq: Changes to get_cpu_idle_time_us(), used by ondemand ↵venkatesh.pallipadi@intel.com
governor export get_cpu_idle_time_us() for it to be used in ondemand governor. Last update time can be current time when the CPU is currently non-idle, accounting for the busy time since last idle. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Dave Jones <davej@redhat.com>
2008-10-09sched debug: add name to sched_domain sysctl entriesIngo Molnar
add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make it easier to see which specific scheduler domain remained at that entry. Since we process the scheduler domain tree and simplify it, it's not always immediately clear during debugging which domain came from where. depends on CONFIG_SCHED_DEBUG=y. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-09Merge branch 'linus' into core/rcuIngo Molnar
2008-10-08sched: sync wakeups vs avg_overlapPeter Zijlstra
While looking at the code I wondered why we always do: sync && avg_overlap < migration_cost Which is a bit odd, since the overlap test was meant to detect sync wakeups so using it to specialize sync wakeups doesn't make much sense. Hence change the code to do: sync || avg_overlap < migration_cost Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-08Merge branches 'sched/devel', 'sched/cpu-hotplug', 'sched/cpusets' and ↵Ingo Molnar
'sched/urgent' into sched/core
2008-10-06kgdb: call touch_softlockup_watchdog on resumeJason Wessel
The softlockup watchdog needs to be touched when resuming the from the kgdb stopped state to avoid the printk that a CPU is stuck if the debugger was active for longer than the softlockup threshold. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-10-06sched: remove redundant code in cpu_cgroup_create()Li Zefan
css will be initialized by cgroup core. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-06Merge branch 'linus' into sched/develIngo Molnar
2008-10-04sched_rt.c: resch needed in rt_rq_enqueue() for the root rt_rqDario Faggioli
While working on the new version of the code for SCHED_SPORADIC I noticed something strange in the present throttling mechanism. More specifically in the throttling timer handler in sched_rt.c (do_sched_rt_period_timer()) and in rt_rq_enqueue(). The problem is that, when unthrottling a runqueue, rt_rq_enqueue() only asks for rescheduling if the runqueue has a sched_entity associated to it (i.e., rt_rq->rt_se != NULL). Now, if the runqueue is the root rq (which has a rt_se = NULL) rescheduling does not take place, and it is delayed to some undefined instant in the future. This imply some random bandwidth usage by the RT tasks under throttling. For instance, setting rt_runtime_us/rt_period_us = 950ms/1000ms an RT task will get less than 95%. In our tests we got something varying between 70% to 95%. Using smaller time values, e.g., 95ms/100ms, things are even worse, and I can see values also going down to 20-25%!! The tests we performed are simply running 'yes' as a SCHED_FIFO task, and checking the CPU usage with top, but we can investigate thoroughly if you think it is needed. Things go much better, for us, with the attached patch... Don't know if it is the best approach, but it solved the issue for us. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-04clockevents: check broadcast tick device not the clock events deviceThomas Gleixner
Impact: jiffies increment too fast. Hugh Dickins noted that with NOHZ=n and HIGHRES=n jiffies get incremented too fast. The reason is a wrong check in the broadcast enter/exit code, which keeps the local apic timer in periodic mode when the switch happens. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-10-03cpusets: scan_for_empty_cpusets(), cpuset doesn't seem to be so constFrederic Weisbecker
This fixes a warning on latest -tip: kernel/cpuset.c: Dans la fonction «scan_for_empty_cpusets» : kernel/cpuset.c:1932: attention : passing argument 1 of «list_add_tail» discards qualifiers from pointer target type Actually the struct cpuset *root passed in parameter to scan_for_empty_cpusets is not supposed to be const since an entry is added on the tail of its list. Just correct the qualifier. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-03rcu: RCU-based detection of stalled CPUs for Classic RCU, fixIngo Molnar
fix the !CONFIG_RCU_CPU_STALL_DETECTOR path: kernel/rcuclassic.c: In function '__rcu_pending': kernel/rcuclassic.c:609: error: too few arguments to function 'check_cpu_stall' Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-03rcu: RCU-based detection of stalled CPUs for Classic RCUPaul E. McKenney
This patch adds stalled-CPU detection to Classic RCU. This capability is enabled by a new config variable CONFIG_RCU_CPU_STALL_DETECTOR, which defaults disabled. This is a debugging feature to detect infinite loops in kernel code, not something that non-kernel-hackers would be expected to care about. This feature can detect looping CPUs in !PREEMPT builds and looping CPUs with preemption disabled in PREEMPT builds. This is essentially a port of this functionality from the treercu patch, replacing the stall debug patch that is already in tip/core/rcu (commit 67182ae1c4). The changes from the patch in tip/core/rcu include making the config variable name match that in treercu, changing from seconds to jiffies to avoid spurious warnings, and printing a boot message when this feature is enabled. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-03Merge commit 'v2.6.27-rc8' into core/rcuIngo Molnar
2008-10-02fix error-path NULL deref in alloc_posix_timer()Dan Carpenter
Found by static checker (http://repo.or.cz/w/smatch.git). Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-30Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: hrtimer: prevent migration of per CPU hrtimers hrtimer: mark migration state hrtimer: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimers hrtimer: migrate pending list on cpu offline Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2008-09-30sched: minor optimizations in wake_affine and select_task_rq_fairAmit K. Arora
This patch does following: o Removes unused variable and argument "rq". o Optimizes one of the "if" conditions in wake_affine() - i.e. if "balanced" is true, we need not do rest of the calculations in the condition. o If this cpu is same as the previous cpu (on which woken up task was running when it went to sleep), no need to call wake_affine at all. Signed-off-by: Amit K Arora <aarora@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-29Configure out file locking featuresThomas Petazzoni
This patch adds the CONFIG_FILE_LOCKING option which allows to remove support for advisory locks. With this patch enabled, the flock() system call, the F_GETLK, F_SETLK and F_SETLKW operations of fcntl() and NFS support are disabled. These features are not necessarly needed on embedded systems. It allows to save ~11 Kb of kernel code and data: text data bss dec hex filename 1125436 118764 212992 1457192 163c28 vmlinux.old 1114299 118564 212992 1445855 160fdf vmlinux -11137 -200 0 -11337 -2C49 +/- This patch has originally been written by Matt Mackall <mpm@selenic.com>, and is part of the Linux Tiny project. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Matt Mackall <mpm@selenic.com> Cc: matthew@wil.cx Cc: linux-fsdevel@vger.kernel.org Cc: mpm@selenic.com Cc: akpm@linux-foundation.org Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2008-09-29mm owner: fix race between swapoff and exitBalbir Singh
There's a race between mm->owner assignment and swapoff, more easily seen when task slab poisoning is turned on. The condition occurs when try_to_unuse() runs in parallel with an exiting task. A similar race can occur with callers of get_task_mm(), such as /proc/<pid>/<mmstats> or ptrace or page migration. CPU0 CPU1 try_to_unuse looks at mm = task0->mm increments mm->mm_users task 0 exits mm->owner needs to be updated, but no new owner is found (mm_users > 1, but no other task has task->mm = task0->mm) mm_update_next_owner() leaves mmput(mm) decrements mm->mm_users task0 freed dereferencing mm->owner fails The fix is to notify the subsystem via mm_owner_changed callback(), if no new owner is found, by specifying the new task as NULL. Jiri Slaby: mm->owner was set to NULL prior to calling cgroup_mm_owner_callbacks(), but must be set after that, so as not to pass NULL as old owner causing oops. Daisuke Nishimura: mm_update_next_owner() may set mm->owner to NULL, but mem_cgroup_from_task() and its callers need to take account of this situation to avoid oops. Hugh Dickins: Lockdep warning and hang below exec_mmap() when testing these patches. exit_mm() up_reads mmap_sem before calling mm_update_next_owner(), so exec_mmap() now needs to do the same. And with that repositioning, there's now no point in mm_need_new_owner() allowing for NULL mm. Reported-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>