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2009-12-15init/main.c: fix symbol shadows noiseH Hartley Sweeten
The symbol 'call' is a static symbol used for initcall_debug. This same symbol name is used locally by a couple functions and produces the following sparse warnings: warning: symbol 'call' shadows an earlier one Fix this noise by renaming the local symbols. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15nommu: fix malloc performance by adding uninitialized flagJie Zhang
The NOMMU code currently clears all anonymous mmapped memory. While this is what we want in the default case, all memory allocation from userspace under NOMMU has to go through this interface, including malloc() which is allowed to return uninitialized memory. This can easily be a significant performance penalty. So for constrained embedded systems were security is irrelevant, allow people to avoid clearing memory unnecessarily. This also alters the ELF-FDPIC binfmt such that it obtains uninitialised memory for the brk and stack region. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-08Merge branch 'timers-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers, init: Limit the number of per cpu calibration bootup messages posix-cpu-timers: optimize and document timer_create callback clockevents: Add missing include to pacify sparse x86: vmiclock: Fix printk format x86: Fix printk format due to variable type change sparc: fix printk for change of variable type clocksource/events: Fix fallout of generic code changes nohz: Allow 32-bit machines to sleep for more than 2.15 seconds nohz: Track last do_timer() cpu nohz: Prevent clocksource wrapping during idle nohz: Type cast printk argument mips: Use generic mult/shift factor calculation for clocks clocksource: Provide a generic mult/shift factor calculation clockevents: Use u32 for mult and shift factors nohz: Introduce arch_needs_cpu nohz: Reuse ktime in sub-functions of tick_check_idle. time: Remove xtime_cache time: Implement logarithmic time accumulation
2009-12-08sysfs: deprecated features are to help old tools not to confuse themUwe Kleine-König
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Greg KH <gregkh@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6: (43 commits) security/tomoyo: Remove now unnecessary handling of security_sysctl. security/tomoyo: Add a special case to handle accesses through the internal proc mount. sysctl: Drop & in front of every proc_handler. sysctl: Remove CTL_NONE and CTL_UNNUMBERED sysctl: kill dead ctl_handler definitions. sysctl: Remove the last of the generic binary sysctl support sysctl net: Remove unused binary sysctl code sysctl security/tomoyo: Don't look at ctl_name sysctl arm: Remove binary sysctl support sysctl x86: Remove dead binary sysctl support sysctl sh: Remove dead binary sysctl support sysctl powerpc: Remove dead binary sysctl support sysctl ia64: Remove dead binary sysctl support sysctl s390: Remove dead sysctl binary support sysctl frv: Remove dead binary sysctl support sysctl mips/lasat: Remove dead binary sysctl support sysctl drivers: Remove dead binary sysctl support sysctl crypto: Remove dead binary sysctl support sysctl security/keys: Remove dead binary sysctl support sysctl kernel: Remove binary sysctl logic ...
2009-12-05Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (31 commits) rcu: Make RCU's CPU-stall detector be default rcu: Add expedited grace-period support for preemptible RCU rcu: Enable fourth level of TREE_RCU hierarchy rcu: Rename "quiet" functions rcu: Re-arrange code to reduce #ifdef pain rcu: Eliminate unneeded function wrapping rcu: Fix grace-period-stall bug on large systems with CPU hotplug rcu: Eliminate __rcu_pending() false positives rcu: Further cleanups of use of lastcomp rcu: Simplify association of forced quiescent states with grace periods rcu: Accelerate callback processing on CPUs not detecting GP end rcu: Mark init-time-only rcu_bootup_announce() as __init rcu: Simplify association of quiescent states with grace periods rcu: Rename dynticks_completed to completed_fqs rcu: Enable synchronize_sched_expedited() fastpath rcu: Remove inline from forward-referenced functions rcu: Fix note_new_gpnum() uses of ->gpnum rcu: Fix synchronization for rcu_process_gp_end() uses of ->completed counter rcu: Prepare for synchronization fixes: clean up for non-NO_HZ handling of ->completed counter rcu: Cleanup: balance rcu_irq_enter()/rcu_irq_exit() calls ...
2009-12-05Merge branch 'core-locking-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mutex: Fix missing conditions to build mutex_spin_on_owner() mutex: Better control mutex adaptive spinning config locking, task_struct: Reduce size on TRACE_IRQFLAGS and 64bit locking: Use __[SPIN|RW]_LOCK_UNLOCKED in [spin|rw]_lock_init() locking: Remove unused prototype locking: Reduce ifdefs in kernel/spinlock.c locking: Make inlining decision Kconfig based
2009-12-02param: don't complain about unused module parameters.Rusty Russell
Jon confirms that recent modprobe will look in /proc/cmdline, so these cmdline options can still be used. See http://bugzilla.kernel.org/show_bug.cgi?id=14164 Reported-by: Adam Williamson <awilliam@redhat.com> Cc: stable@kernel.org Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-01sysfs: fix SYSFS_DEPRECATED_V2 promptRandy Dunlap
The SYSFS_DEPRECATED_V2 says "remove" older, deprecated features, but it actually enables them, so correct this confusing, backwards text. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-01SLOW_WORK: Move slow_work's proc file to debugfsDavid Howells
Move slow_work's debugging proc file to debugfs. Signed-off-by: David Howells <dhowells@redhat.com> Requested-and-acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-26timers, init: Limit the number of per cpu calibration bootup messagesMike Travis
Limit the number of per cpu calibration messages by only printing out results for the first cpu to boot. Also, don't print "CPUx is down" as this is expected, and we don't need 4096 reminders... ;-) Signed-off-by: Mike Travis <travis@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Yinghai Lu <yhlu.kernel@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091118002219.889552000@alcatraz.americas.sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-11-19SLOW_WORK: Allow the work items to be viewed through a /proc fileDavid Howells
Allow the executing and queued work items to be viewed through a /proc file for debugging purposes. The contents look something like the following: THR PID ITEM ADDR FL MARK DESC === ===== ================ == ===== ========== 0 3005 ffff880023f52348 a 952ms FSC: OBJ17d3: LOOK 1 3006 ffff880024e33668 2 160ms FSC: OBJ17e5 OP60d3b: Write1/Store fl=2 2 3165 ffff8800296dd180 a 424ms FSC: OBJ17e4: LOOK 3 4089 ffff8800262c8d78 a 212ms FSC: OBJ17ea: CRTN 4 4090 ffff88002792bed8 2 388ms FSC: OBJ17e8 OP60d36: Write1/Store fl=2 5 4092 ffff88002a0ef308 2 388ms FSC: OBJ17e7 OP60d2e: Write1/Store fl=2 6 4094 ffff88002abaf4b8 2 132ms FSC: OBJ17e2 OP60d4e: Write1/Store fl=2 7 4095 ffff88002bb188e0 a 388ms FSC: OBJ17e9: CRTN vsq - ffff880023d99668 1 308ms FSC: OBJ17e0 OP60f91: Write1/EnQ fl=2 vsq - ffff8800295d1740 1 212ms FSC: OBJ16be OP4d4b6: Write1/EnQ fl=2 vsq - ffff880025ba3308 1 160ms FSC: OBJ179a OP58dec: Write1/EnQ fl=2 vsq - ffff880024ec83e0 1 160ms FSC: OBJ17ae OP599f2: Write1/EnQ fl=2 vsq - ffff880026618e00 1 160ms FSC: OBJ17e6 OP60d33: Write1/EnQ fl=2 vsq - ffff880025a2a4b8 1 132ms FSC: OBJ16a2 OP4d583: Write1/EnQ fl=2 vsq - ffff880023cbe6d8 9 212ms FSC: OBJ17eb: LOOK vsq - ffff880024d37590 9 212ms FSC: OBJ17ec: LOOK vsq - ffff880027746cb0 9 212ms FSC: OBJ17ed: LOOK vsq - ffff880024d37ae8 9 212ms FSC: OBJ17ee: LOOK vsq - ffff880024d37cb0 9 212ms FSC: OBJ17ef: LOOK vsq - ffff880025036550 9 212ms FSC: OBJ17f0: LOOK vsq - ffff8800250368e0 9 212ms FSC: OBJ17f1: LOOK vsq - ffff880025036aa8 9 212ms FSC: OBJ17f2: LOOK In the 'THR' column, executing items show the thread they're occupying and queued threads indicate which queue they're on. 'PID' shows the process ID of a slow-work thread that's executing something. 'FL' shows the work item flags. 'MARK' indicates how long since an item was queued or began executing. Lastly, the 'DESC' column permits the owner of an item to give some information. Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-17Merge commit 'v2.6.32-rc7'Eric W. Biederman
Resolve the conflict between v2.6.32-rc7 where dn_def_dev_handler gets a small bug fix and the sysctl tree where I am removing all sysctl strategy routines.
2009-11-13locking: Make inlining decision Kconfig basedThomas Gleixner
commit 892a7c67 (locking: Allow arch-inlined spinlocks) implements the selection of which lock functions are inlined based on defines in arch/.../spinlock.h: #define __always_inline__LOCK_FUNCTION Despite of the name __always_inline__* the lock functions can be built out of line depending on config options. Also if the arch does not set some inline defines the generic code might set them; again depending on config options. This makes it unnecessary hard to figure out when and which lock functions are inlined. Aside of that it makes it way harder and messier for -rt to manipulate the lock functions. Convert the inlining decision to CONFIG switches. Each lock function is inlined depending on CONFIG_INLINE_*. The configs implement the existing dependencies. The architecture code can select ARCH_INLINE_* to signal that it wants the corresponding lock function inlined. ARCH_INLINE_* is necessary as Kconfig ignores "depends on" restrictions when a config element is selected. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <20091109151428.504477141@linutronix.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Ingo Molnar <mingo@elte.hu> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
2009-11-11Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tools: Fix permission checks perf_events: Fix some typo in the perf events config description
2009-11-11sysctl: Reduce sys_sysctl to a compatibility wrapper around /proc/sysEric W. Biederman
To simply maintenance and to be able to remove all of the binary sysctl support from various subsystems I have rewritten the binary sysctl code as a compatibility wrapper around proc/sys. The code is built around a hard coded table based on the table in sysctl_check.c that lists all of our current binary sysctls and provides enough information to convert from the sysctl binary input into into ascii and back again. New in this patch is the realization that the only dynamic entries that need to be handled have ifname as the asscii string and ifindex as their ctl_name. When a sys_sysctl is called the code now looks in the translation table converting the binary name to the path under /proc where the value is to be found. Opens that file, and calls into a format conversion wrapper that calls fop->read and then fop->write as appropriate. Since in practice the practically no one uses or tests sys_sysctl rewritting the code to be beautiful is a little silly. The redeeming merit of this work is it allows us to rip out all of the binary sysctl syscall support from everywhere else in the tree. Allowing us to remove a lot of dead (after this patch) and barely maintained code. In addition it becomes much easier to optimize the sysctl implementation for being the backing store of /proc/sys, without having to worry about sys_sysctl. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-02perf_events: Fix some typo in the perf events config descriptionThadeu Lima de Souza Cascardo
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: trivial@kernel.org LKML-Reference: <1256938346-8230-1-git-send-email-cascardo@holoscopio.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-27powerpc: Minor cleanup to init/KconfigKumar Gala
We dont need to depend on PPC64 explicitly as all powerpc platforms (32-bit and 64-bit) define PPC now. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-26rcu: "Tiny RCU", The Bloatwatch EditionPaul E. McKenney
This patch is a version of RCU designed for !SMP provided for a small-footprint RCU implementation. In particular, the implementation of synchronize_rcu() is extremely lightweight and high performance. It passes rcutorture testing in each of the four relevant configurations (combinations of NO_HZ and PREEMPT) on x86. This saves about 1K bytes compared to old Classic RCU (which is no longer in mainline), and more than three kilobytes compared to Hierarchical RCU (updated to 2.6.30): CONFIG_TREE_RCU: text data bss dec filename 183 4 0 187 kernel/rcupdate.o 2783 520 36 3339 kernel/rcutree.o 3526 Total (vs 4565 for v7) CONFIG_TREE_PREEMPT_RCU: text data bss dec filename 263 4 0 267 kernel/rcupdate.o 4594 776 52 5422 kernel/rcutree.o 5689 Total (6155 for v7) CONFIG_TINY_RCU: text data bss dec filename 96 4 0 100 kernel/rcupdate.o 734 24 0 758 kernel/rcutiny.o 858 Total (vs 848 for v7) The above is for x86. Your mileage may vary on other platforms. Further compression is possible, but is being procrastinated. Changes from v7 (http://lkml.org/lkml/2009/10/9/388) o Apply Lai Jiangshan's review comments (aside from might_sleep() in synchronize_sched(), which is covered by SMP builds). o Fix up expedited primitives. Changes from v6 (http://lkml.org/lkml/2009/9/23/293). o Forward ported to put it into the 2.6.33 stream. o Added lockdep support. o Make lightweight rcu_barrier. Changes from v5 (http://lkml.org/lkml/2009/6/23/12). o Ported to latest pre-2.6.32 merge window kernel. - Renamed rcu_qsctr_inc() to rcu_sched_qs(). - Renamed rcu_bh_qsctr_inc() to rcu_bh_qs(). - Provided trivial rcu_cpu_notify(). - Provided trivial exit_rcu(). - Provided trivial rcu_needs_cpu(). - Fixed up the rcu_*_enter/exit() functions in linux/hardirq.h. o Removed the dependence on EMBEDDED, with a view to making TINY_RCU default for !SMP at some time in the future. o Added (trivial) support for expedited grace periods. Changes from v4 (http://lkml.org/lkml/2009/5/2/91) include: o Squeeze the size down a bit further by removing the ->completed field from struct rcu_ctrlblk. o This permits synchronize_rcu() to become the empty function. Previous concerns about rcutorture were unfounded, as rcutorture correctly handles a constant value from rcu_batches_completed() and rcu_batches_completed_bh(). Changes from v3 (http://lkml.org/lkml/2009/3/29/221) include: o Changed rcu_batches_completed(), rcu_batches_completed_bh() rcu_enter_nohz(), rcu_exit_nohz(), rcu_nmi_enter(), and rcu_nmi_exit(), to be static inlines, as suggested by David Howells. Doing this saves about 100 bytes from rcutiny.o. (The numbers between v3 and this v4 of the patch are not directly comparable, since they are against different versions of Linux.) Changes from v2 (http://lkml.org/lkml/2009/2/3/333) include: o Fix whitespace issues. o Change short-circuit "||" operator to instead be "+" in order to fix performance bug noted by "kraai" on LWN. (http://lwn.net/Articles/324348/) Changes from v1 (http://lkml.org/lkml/2009/1/13/440) include: o This version depends on EMBEDDED as well as !SMP, as suggested by Ingo. o Updated rcu_needs_cpu() to unconditionally return zero, permitting the CPU to enter dynticks-idle mode at any time. This works because callbacks can be invoked upon entry to dynticks-idle mode. o Paul is now OK with this being included, based on a poll at the Kernel Miniconf at linux.conf.au, where about ten people said that they cared about saving 900 bytes on single-CPU systems. o Applies to both mainline and tip/core/rcu. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351355-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-08Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: futex: fix requeue_pi key imbalance futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions rcu: Place root rcu_node structure in separate lockdep class rcu: Make hot-unplugged CPU relinquish its own RCU callbacks rcu: Move rcu_barrier() to rcutree futex: Move exit_pi_state() call to release_mm() futex: Nullify robust lists after cleanup futex: Fix locking imbalance panic: Fix panic message visibility by calling bust_spinlocks(0) before dying rcu: Replace the rcu_barrier enum with pointer to call_rcu*() function rcu: Clean up code based on review feedback from Josh Triplett, part 4 rcu: Clean up code based on review feedback from Josh Triplett, part 3 rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=y rcu: Clean up code to address Ingo's checkpatch feedback rcu: Clean up code based on review feedback from Josh Triplett, part 2 rcu: Clean up code based on review feedback from Josh Triplett
2009-10-06perf_event: Provide vmalloc() based mmap() backingPeter Zijlstra
Some architectures such as Sparc, ARM and MIPS (basically everything with flush_dcache_page()) need to deal with dcache aliases by carefully placing pages in both kernel and user maps. These architectures typically have to use vmalloc_user() for this. However, on other architectures, vmalloc() is not needed and has the downsides of being more restricted and slower than regular allocations. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: David Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1254830228.21044.272.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (39 commits) cpumask: Move deprecated functions to end of header. cpumask: remove unused deprecated functions, avoid accusations of insanity cpumask: use new-style cpumask ops in mm/quicklist. cpumask: use mm_cpumask() wrapper: x86 cpumask: use mm_cpumask() wrapper: um cpumask: use mm_cpumask() wrapper: mips cpumask: use mm_cpumask() wrapper: mn10300 cpumask: use mm_cpumask() wrapper: m32r cpumask: use mm_cpumask() wrapper: arm cpumask: Use accessors for cpu_*_mask: um cpumask: Use accessors for cpu_*_mask: powerpc cpumask: Use accessors for cpu_*_mask: mips cpumask: Use accessors for cpu_*_mask: m32r cpumask: remove arch_send_call_function_ipi cpumask: arch_send_call_function_ipi_mask: s390 cpumask: arch_send_call_function_ipi_mask: powerpc cpumask: arch_send_call_function_ipi_mask: mips cpumask: arch_send_call_function_ipi_mask: m32r cpumask: arch_send_call_function_ipi_mask: alpha cpumask: remove obsolete topology_core_siblings and topology_thread_siblings: ia64 ...
2009-09-23headers: utsname.h reduxAlexey Dobriyan
* remove asm/atomic.h inclusion from linux/utsname.h -- not needed after kref conversion * remove linux/utsname.h inclusion from files which do not need it NOTE: it looks like fs/binfmt_elf.c do not need utsname.h, however due to some personality stuff it _is_ needed -- cowardly leave ELF-related headers and files alone. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-24cpumask: remove unused cpu_mask_allRusty Russell
It's only defined for NR_CPUS > BITS_PER_LONG; cpu_all_mask is always defined (and const). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-nextLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-next: (30 commits) Use macros for .data.page_aligned section. Use macros for .bss.page_aligned section. Use new __init_task_data macro in arch init_task.c files. kbuild: Don't define ALIGN and ENTRY when preprocessing linker scripts. arm, cris, mips, sparc, powerpc, um, xtensa: fix build with bash 4.0 kbuild: add static to prototypes kbuild: fail build if recordmcount.pl fails kbuild: set -fconserve-stack option for gcc 4.5 kbuild: echo the record_mcount command gconfig: disable "typeahead find" search in treeviews kbuild: fix cc1 options check to ensure we do not use -fPIC when compiling checkincludes.pl: add option to remove duplicates in place markup_oops: use modinfo to avoid confusion with underscored module names checkincludes.pl: provide usage helper checkincludes.pl: close file as soon as we're done with it ctags: usability fix kernel hacking: move STRIP_ASM_SYMS from General gitignore usr/initramfs_data.cpio.bz2 and usr/initramfs_data.cpio.lzma kbuild: Check if linker supports the -X option kbuild: introduce ld-option ... Fix trivial conflict in scripts/basic/fixdep.c
2009-09-23rcu: Clean up code based on review feedback from Josh Triplett, part 2Paul E. McKenney
These issues identified during an old-fashioned face-to-face code review extending over many hours. o Add comments for tricky parts of code, and correct comments that have passed their sell-by date. o Get rid of the vestiges of rcu_init_sched(), which is no longer needed now that PREEMPT_RCU is gone. o Move the #include of rcutree_plugin.h to the end of rcutree.c, which means that, rather than having a random collection of forward declarations, the new set of forward declarations document the set of plugins. The new home for this #include also allows __rcu_init_preempt() to move into rcutree_plugin.h. o Fix rcu_preempt_check_callbacks() to be static. Suggested-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <12537246443924-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu> Peter Zijlstra <peterz@infradead.org>
2009-09-23Merge branch 'sfi-release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-sfi-2.6 * 'sfi-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-sfi-2.6: SFI: remove unneeded includes sfi: Remove unused code SFI: Hook PCI MMCONFIG x86: add arch-specific SFI support SFI: add capability to parse ACPI tables SFI: add platform-independent core support SFI: create linux/sfi.h SFI: Simple Firmware Interface - MAINTAINERS, Kconfig
2009-09-22mm: replace various uses of num_physpages by totalram_pagesJan Beulich
Sizing of memory allocations shouldn't depend on the number of physical pages found in a system, as that generally includes (perhaps a huge amount of) non-RAM pages. The amount of what actually is usable as storage should instead be used as a basis here. Some of the calculations (i.e. those not intending to use high memory) should likely even use (totalram_pages - totalhigh_pages). Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Dave Airlie <airlied@linux.ie> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Patrick McHardy <kaber@trash.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-21Merge branch 'perfcounters-rename-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perfcounters-rename-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Tidy up after the big rename perf: Do the big rename: Performance Counters -> Performance Events perf_counter: Rename 'event' to event_id/hw_event perf_counter: Rename list_entry -> group_entry, counter_list -> group_list Manually resolved some fairly trivial conflicts with the tracing tree in include/trace/ftrace.h and kernel/trace/trace_syscalls.c.
2009-09-21Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Fix whitespace inconsistencies rcu: Fix thinko, actually initialize full tree rcu: Apply results of code inspection of kernel/rcutree_plugin.h rcu: Add WARN_ON_ONCE() consistency checks covering state transitions rcu: Fix synchronize_rcu() for TREE_PREEMPT_RCU rcu: Simplify rcu_read_unlock_special() quiescent-state accounting rcu: Add debug checks to TREE_PREEMPT_RCU for premature grace periods rcu: Kconfig help needs to say that TREE_PREEMPT_RCU scales down rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state rcu: Initialize multi-level RCU grace periods holding locks rcu: Need to update rnp->gpnum if preemptable RCU is to be reliable
2009-09-21perf: Tidy up after the big renameIngo Molnar
- provide compatibility Kconfig entry for existing PERF_COUNTERS .config's - provide courtesy copy of old perf_counter.h, for user-space projects - small indentation fixups - fix up MAINTAINERS - fix small x86 printout fallout - fix up small PowerPC comment fallout (use 'counter' as in register) Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-21perf: Do the big rename: Performance Counters -> Performance EventsIngo Molnar
Bye-bye Performance Counters, welcome Performance Events! In the past few months the perfcounters subsystem has grown out its initial role of counting hardware events, and has become (and is becoming) a much broader generic event enumeration, reporting, logging, monitoring, analysis facility. Naming its core object 'perf_counter' and naming the subsystem 'perfcounters' has become more and more of a misnomer. With pending code like hw-breakpoints support the 'counter' name is less and less appropriate. All in one, we've decided to rename the subsystem to 'performance events' and to propagate this rename through all fields, variables and API names. (in an ABI compatible fashion) The word 'event' is also a bit shorter than 'counter' - which makes it slightly more convenient to write/handle as well. Thanks goes to Stephane Eranian who first observed this misnomer and suggested a rename. User-space tooling and ABI compatibility is not affected - this patch should be function-invariant. (Also, defconfigs were not touched to keep the size down.) This patch has been generated via the following script: FILES=$(find * -type f | grep -vE 'oprofile|[^K]config') sed -i \ -e 's/PERF_EVENT_/PERF_RECORD_/g' \ -e 's/PERF_COUNTER/PERF_EVENT/g' \ -e 's/perf_counter/perf_event/g' \ -e 's/nb_counters/nb_events/g' \ -e 's/swcounter/swevent/g' \ -e 's/tpcounter_event/tp_event/g' \ $FILES for N in $(find . -name perf_counter.[ch]); do M=$(echo $N | sed 's/perf_counter/perf_event/g') mv $N $M done FILES=$(find . -name perf_event.*) sed -i \ -e 's/COUNTER_MASK/REG_MASK/g' \ -e 's/COUNTER/EVENT/g' \ -e 's/\<event\>/event_id/g' \ -e 's/counter/event/g' \ -e 's/Counter/Event/g' \ $FILES ... to keep it as correct as possible. This script can also be used by anyone who has pending perfcounters patches - it converts a Linux kernel tree over to the new naming. We tried to time this change to the point in time where the amount of pending patches is the smallest: the end of the merge window. Namespace clashes were fixed up in a preparatory patch - and some stylistic fallout will be fixed up in a subsequent patch. ( NOTE: 'counters' are still the proper terminology when we deal with hardware registers - and these sed scripts are a bit over-eager in renaming them. I've undone some of that, but in case there's something left where 'counter' would be better than 'event' we can undo that on an individual basis instead of touching an otherwise nicely automated patch. ) Suggested-by: Stephane Eranian <eranian@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Arjan van de Ven <arjan@linux.intel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <linux-arch@vger.kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-20kernel hacking: move STRIP_ASM_SYMS from GeneralRandy Dunlap
Sam suggested moving STRIP_ASM_SYMS into the Kernel hacking menu from the General Setup menu. It makes more sense there. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2009-09-19Merge branch 'linus' into sfi-releaseLen Brown
Conflicts: arch/x86/kernel/setup.c drivers/acpi/power.c init/main.c Signed-off-by: Len Brown <len.brown@intel.com>
2009-09-18tracing: Remove markersChristoph Hellwig
Now that the last users of markers have migrated to the event tracer we can kill off the (now orphan) support code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20090917173527.GA1699@lst.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-18rcu: Kconfig help needs to say that TREE_PREEMPT_RCU scales downPaul E. McKenney
To quote Valdis: This leaves somebody who has a laptop wondering which choice is best for a system with only one or two cores that has CONFIG_PREEMPT defined. One choice says it scales down nicely, the other explicitly has a 'depends on PREEMPT' attached to it... So add "scales down nicely" to TREE_PREEMPT_RCU to match that of TREE_RCU. Suggested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12528585112362-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-16Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev debugfs: Modify default debugfs directory for debugging pktcdvd. debugfs: Modified default dir of debugfs for debugging UHCI. debugfs: Change debugfs directory of IWMC3200 debugfs: Change debuhgfs directory of trace-events-sample.h debugfs: Fix mount directory of debugfs by default in events.txt hpilo: add poll f_op hpilo: add interrupt handler hpilo: staging for interrupt handling driver core: platform_device_add_data(): use kmemdup() Driver core: Add support for compatibility classes uio: add generic driver for PCI 2.3 devices driver-core: move dma-coherent.c from kernel to driver/base mem_class: fix bug mem_class: use minor as index instead of searching the array driver model: constify attribute groups UIO: remove 'default n' from Kconfig Driver core: Add accessor for device platform data Driver core: move dev_get/set_drvdata to drivers/base/dd.c Driver core: add new device to bus's list before probing
2009-09-15Driver Core: devtmpfs - kernel-maintained tmpfs-based /devKay Sievers
Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (46 commits) powerpc64: convert to dynamic percpu allocator sparc64: use embedding percpu first chunk allocator percpu: kill lpage first chunk allocator x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA percpu: update embedding first chunk allocator to handle sparse units percpu: use group information to allocate vmap areas sparsely vmalloc: implement pcpu_get_vm_areas() vmalloc: separate out insert_vmalloc_vm() percpu: add chunk->base_addr percpu: add pcpu_unit_offsets[] percpu: introduce pcpu_alloc_info and pcpu_group_info percpu: move pcpu_lpage_build_unit_map() and pcpul_lpage_dump_cfg() upward percpu: add @align to pcpu_fc_alloc_fn_t percpu: make @dyn_size mandatory for pcpu_setup_first_chunk() percpu: drop @static_size from first chunk allocators percpu: generalize first chunk allocator selection percpu: build first chunk allocators selectively percpu: rename 4k first chunk allocator to page percpu: improve boot messages percpu: fix pcpu_reclaim() locking ... Fix trivial conflict as by Tejun Heo in kernel/sched.c
2009-09-11Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (64 commits) sched: Fix sched::sched_stat_wait tracepoint field sched: Disable NEW_FAIR_SLEEPERS for now sched: Keep kthreads at default priority sched: Re-tune the scheduler latency defaults to decrease worst-case latencies sched: Turn off child_runs_first sched: Ensure that a child can't gain time over it's parent after fork() sched: enable SD_WAKE_IDLE sched: Deal with low-load in wake_affine() sched: Remove short cut from select_task_rq_fair() sched: Turn on SD_BALANCE_NEWIDLE sched: Clean up topology.h sched: Fix dynamic power-balancing crash sched: Remove reciprocal for cpu_power sched: Try to deal with low capacity, fix update_sd_power_savings_stats() sched: Try to deal with low capacity sched: Scale down cpu_power due to RT tasks sched: Implement dynamic cpu_power sched: Add smt_gain sched: Update the cpu_power sum during load-balance sched: Add SD_PREFER_SIBLING ...
2009-09-04rcu: Move end of special early-boot RCU operation earlierPaul E. McKenney
Ingo was getting warnings from rcu_scheduler_starting() indicating that context switches had occurred before RCU ended its special early-boot handling of grace periods. This is a dangerous condition, as it indicates that RCU might have prematurely ended grace periods. This exploratory fix moves rcu_scheduler_starting() earlier in boot. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-09-04Merge branch 'linus' into core/rcuIngo Molnar
Merge reason: Avoid fuzz in init/main.c and update from rc6 to rc8. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-28SFI: add platform-independent core supportFeng Tang
drivers/sfi/sfi_core.c contains the generic SFI implementation. It has a private header, sfi_core.h, for its own use and the private use of future files in drivers/sfi/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-27init: Move sched_clock_init after late_time_initThomas Gleixner
Some architectures initialize clocks and timers in late_time_init and x86 wants to do the same to avoid FIXMAP hackery for calibrating the TSC. That would result in undefined sched_clock readout and wreckaged printk timestamps again. We probably have those already on archs which do all their time/clock setup in late_time_init. There is no harm to move that after late_time_init except that a few more boot timestamps are stale. The scheduler is not active at that point so no real wreckage is expected. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Cc: linux-arch@vger.kernel.org
2009-08-25Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix too large stack usage in do_one_initcall() tracing: handle broken names in ftrace filter ftrace: Unify effect of writing to trace_options and option/*
2009-08-23rcu: Remove CONFIG_PREEMPT_RCUPaul E. McKenney
Now that CONFIG_TREE_PREEMPT_RCU is in place, there is no further need for CONFIG_PREEMPT_RCU. Remove it, along with whatever subtle bugs it may (or may not) contain. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <125097461396-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-23rcu: Merge preemptable-RCU functionality into hierarchical RCUPaul E. McKenney
Create a kernel/rcutree_plugin.h file that contains definitions for preemptable RCU (or, under the #else branch of the #ifdef, empty definitions for the classic non-preemptable semantics). These definitions fit into plugins defined in kernel/rcutree.c for this purpose. This variant of preemptable RCU uses a new algorithm whose read-side expense is roughly that of classic hierarchical RCU under CONFIG_PREEMPT. This new algorithm's update-side expense is similar to that of classic hierarchical RCU, and, in absence of read-side preemption or blocking, is exactly that of classic hierarchical RCU. Perhaps more important, this new algorithm has a much simpler implementation, saving well over 1,000 lines of code compared to mainline's implementation of preemptable RCU, which will hopefully be retired in favor of this new algorithm. The simplifications are obtained by maintaining per-task nesting state for running tasks, and using a simple lock-protected algorithm to handle accounting when tasks block within RCU read-side critical sections, making use of lessons learned while creating numerous user-level RCU implementations over the past 18 months. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: akpm@linux-foundation.org Cc: mathieu.desnoyers@polymtl.ca Cc: josht@linux.vnet.ibm.com Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org LKML-Reference: <12509746134003-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-21tracing: Fix too large stack usage in do_one_initcall()Ingo Molnar
One of my testboxes triggered this nasty stack overflow crash during SCSI probing: [ 5.874004] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 5.875004] device: 'sda': device_add [ 5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c [ 5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110 [ 5.878004] *pde = 00000000 [ 5.878004] Thread overran stack, or stack corrupted [ 5.878004] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 5.878004] last sysfs file: [ 5.878004] [ 5.878004] Pid: 1, comm: swapper Not tainted (2.6.31-rc6-tip-01272-g9919e28-dirty #5685) [ 5.878004] EIP: 0060:[<b1008321>] EFLAGS: 00010083 CPU: 0 [ 5.878004] EIP is at print_context_stack+0x81/0x110 [ 5.878004] EAX: cf8a3000 EBX: cf8a3fe4 ECX: 00000049 EDX: 00000000 [ 5.878004] ESI: b1cfce84 EDI: 00000000 EBP: cf8a3018 ESP: cf8a2ff4 [ 5.878004] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 [ 5.878004] Process swapper (pid: 1, ti=cf8a2000 task=cf8a8000 task.ti=cf8a3000) [ 5.878004] Stack: [ 5.878004] b1004867 fffff000 cf8a3ffc [ 5.878004] Call Trace: [ 5.878004] [<b1004867>] ? kernel_thread_helper+0x7/0x10 [ 5.878004] BUG: unable to handle kernel NULL pointer dereference at 00000a0c [ 5.878004] IP: [<b1008321>] print_context_stack+0x81/0x110 [ 5.878004] *pde = 00000000 [ 5.878004] Thread overran stack, or stack corrupted [ 5.878004] Oops: 0000 [#2] PREEMPT SMP DEBUG_PAGEALLOC The oops did not reveal any more details about the real stack that we have and the system got into an infinite loop of recursive pagefaults. So i booted with CONFIG_STACK_TRACER=y and the 'stacktrace' boot parameter. The box did not crash (timings/conditions probably changed a tiny bit to trigger the catastrophic crash), but the /debug/tracing/stack_trace file was rather revealing: Depth Size Location (72 entries) ----- ---- -------- 0) 3704 52 __change_page_attr+0xb8/0x290 1) 3652 24 __change_page_attr_set_clr+0x43/0x90 2) 3628 60 kernel_map_pages+0x108/0x120 3) 3568 40 prep_new_page+0x7d/0x130 4) 3528 84 get_page_from_freelist+0x106/0x420 5) 3444 116 __alloc_pages_nodemask+0xd7/0x550 6) 3328 36 allocate_slab+0xb1/0x100 7) 3292 36 new_slab+0x1c/0x160 8) 3256 36 __slab_alloc+0x133/0x2b0 9) 3220 4 kmem_cache_alloc+0x1bb/0x1d0 10) 3216 108 create_object+0x28/0x250 11) 3108 40 kmemleak_alloc+0x81/0xc0 12) 3068 24 kmem_cache_alloc+0x162/0x1d0 13) 3044 52 scsi_pool_alloc_command+0x29/0x70 14) 2992 20 scsi_host_alloc_command+0x22/0x70 15) 2972 24 __scsi_get_command+0x1b/0x90 16) 2948 28 scsi_get_command+0x35/0x90 17) 2920 24 scsi_setup_blk_pc_cmnd+0xd4/0x100 18) 2896 128 sd_prep_fn+0x332/0xa70 19) 2768 36 blk_peek_request+0xe7/0x1d0 20) 2732 56 scsi_request_fn+0x54/0x520 21) 2676 12 __generic_unplug_device+0x2b/0x40 22) 2664 24 blk_execute_rq_nowait+0x59/0x80 23) 2640 172 blk_execute_rq+0x6b/0xb0 24) 2468 32 scsi_execute+0xe0/0x140 25) 2436 64 scsi_execute_req+0x152/0x160 26) 2372 60 scsi_vpd_inquiry+0x6c/0x90 27) 2312 44 scsi_get_vpd_page+0x112/0x160 28) 2268 52 sd_revalidate_disk+0x1df/0x320 29) 2216 92 rescan_partitions+0x98/0x330 30) 2124 52 __blkdev_get+0x309/0x350 31) 2072 8 blkdev_get+0xf/0x20 32) 2064 44 register_disk+0xff/0x120 33) 2020 36 add_disk+0x6e/0xb0 34) 1984 44 sd_probe_async+0xfb/0x1d0 35) 1940 44 __async_schedule+0xf4/0x1b0 36) 1896 8 async_schedule+0x12/0x20 37) 1888 60 sd_probe+0x305/0x360 38) 1828 44 really_probe+0x63/0x170 39) 1784 36 driver_probe_device+0x5d/0x60 40) 1748 16 __device_attach+0x49/0x50 41) 1732 32 bus_for_each_drv+0x5b/0x80 42) 1700 24 device_attach+0x6b/0x70 43) 1676 16 bus_attach_device+0x47/0x60 44) 1660 76 device_add+0x33d/0x400 45) 1584 52 scsi_sysfs_add_sdev+0x6a/0x2c0 46) 1532 108 scsi_add_lun+0x44b/0x460 47) 1424 116 scsi_probe_and_add_lun+0x182/0x4e0 48) 1308 36 __scsi_add_device+0xd9/0xe0 49) 1272 44 ata_scsi_scan_host+0x10b/0x190 50) 1228 24 async_port_probe+0x96/0xd0 51) 1204 44 __async_schedule+0xf4/0x1b0 52) 1160 8 async_schedule+0x12/0x20 53) 1152 48 ata_host_register+0x171/0x1d0 54) 1104 60 ata_pci_sff_activate_host+0xf3/0x230 55) 1044 44 ata_pci_sff_init_one+0xea/0x100 56) 1000 48 amd_init_one+0xb2/0x190 57) 952 8 local_pci_probe+0x13/0x20 58) 944 32 pci_device_probe+0x68/0x90 59) 912 44 really_probe+0x63/0x170 60) 868 36 driver_probe_device+0x5d/0x60 61) 832 20 __driver_attach+0x89/0xa0 62) 812 32 bus_for_each_dev+0x5b/0x80 63) 780 12 driver_attach+0x1e/0x20 64) 768 72 bus_add_driver+0x14b/0x2d0 65) 696 36 driver_register+0x6e/0x150 66) 660 20 __pci_register_driver+0x53/0xc0 67) 640 8 amd_init+0x14/0x16 68) 632 572 do_one_initcall+0x2b/0x1d0 69) 60 12 do_basic_setup+0x56/0x6a 70) 48 20 kernel_init+0x84/0xce 71) 28 28 kernel_thread_helper+0x7/0x10 There's a lot of fat functions on that stack trace, but the largest of all is do_one_initcall(). This is due to the boot trace entry variables being on the stack. Fixing this is relatively easy, initcalls are fundamentally serialized, so we can move the local variables to file scope. Note that this large stack footprint was present for a couple of months already - what pushed my system over the edge was the addition of kmemleak to the call-chain: 6) 3328 36 allocate_slab+0xb1/0x100 7) 3292 36 new_slab+0x1c/0x160 8) 3256 36 __slab_alloc+0x133/0x2b0 9) 3220 4 kmem_cache_alloc+0x1bb/0x1d0 10) 3216 108 create_object+0x28/0x250 11) 3108 40 kmemleak_alloc+0x81/0xc0 12) 3068 24 kmem_cache_alloc+0x162/0x1d0 13) 3044 52 scsi_pool_alloc_command+0x29/0x70 This pushes the total to ~3800 bytes, only a tiny bit more was needed to corrupt the on-kernel-stack thread_info. The fix reduces the stack footprint from 572 bytes to 28 bytes. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@kernel.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-15Merge commit 'v2.6.31-rc6' into core/rcuIngo Molnar
Merge reason: the branch was on pre-rc1 .30, update to latest. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-08-14Merge branch 'percpu-for-linus' into percpu-for-nextTejun Heo
Conflicts: arch/sparc/kernel/smp_64.c arch/x86/kernel/cpu/perf_counter.c arch/x86/kernel/setup_percpu.c drivers/cpufreq/cpufreq_ondemand.c mm/percpu.c Conflicts in core and arch percpu codes are mostly from commit ed78e1e078dd44249f88b1dd8c76dafb39567161 which substituted many num_possible_cpus() with nr_cpu_ids. As for-next branch has moved all the first chunk allocators into mm/percpu.c, the changes are moved from arch code to mm/percpu.c. Signed-off-by: Tejun Heo <tj@kernel.org>