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2006-03-23[PATCH] kernel/rcupdate.c: make two structs staticAdrian Bunk
This patch makes two needlessly global structs static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] BUILD_LOCK_OPS: cleanup preempt_disable() usageOleg Nesterov
This patch changes the code from: preempt_disable(); for (;;) { ... preempt_disable(); } to: for (;;) { preempt_disable(); ... } which seems more clean to me and saves a couple of bytes for each function. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] pause_on_oops command line optionAndrew Morton
Attempt to fix the problem wherein people's oops reports scroll off the screen due to repeated oopsing or to oopses on other CPUs. If this happens the user can reboot with the `pause_on_oops=<seconds>' option. It will allow the first oopsing CPU to print an oops record just a single time. Second oopsing attempts, or oopses on other CPUs will cause those CPUs to enter a tight loop until the specified number of seconds have elapsed. The patch implements the infrastructure generically in the expectation that architectures other than x86 will find it useful. Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] make bug messages more consistentIngo Molnar
Consolidate all kernel bug printouts to begin with the "BUG: " string. Makes it easier to find them in large bootup logs. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] sigprocmask: kill unneeded temp varOleg Nesterov
Cleanup, remove unneeded double copying of current->blocked. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] kernel/module.c Semaphore to Mutex Conversion for module_mutexAshutosh Naik
This patch converts the module_mutex semaphore to a mutex. Signed-off-by: Ashutosh Naik <ashutosh.naik@gmail.com> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] sem2mutex: kprobesIngo Molnar
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] sem2mutex: ttyIngo Molnar
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] sem2mutex: kernel/Arjan van de Ven
Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] convert kernel/rcupdate.c:rcu_barrier_sema to mutexIngo Molnar
Convert kernel/rcupdate's rcu_barrier_sema to mutex. Signed-off-by: Ingo Molnar <mingo@elte.hu> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] kernel/cpuset.c, mutex conversionIngo Molnar
convert cpuset.c's callback_sem and manage_sem to mutexes. Build and boot tested by Ingo. Build, boot, unit and stress tested by pj. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] Avoid taking global tasklist_lock for single threadedprocess at ↵Ravikiran G Thirumalai
getrusage() Avoid taking the global tasklist_lock when possible, if a process is single threaded during getrusage(). Any avoidance of tasklist_lock is good for NUMA boxes (and possibly for large SMPs). Thanks to Oleg Nesterov for review and suggestions. Signed-off-by: Nippun Goel <nippung@calsoftinc.com> Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] Shrinks sizeof(files_struct) and better layoutEric Dumazet
1) Reduce the size of (struct fdtable) to exactly 64 bytes on 32bits platforms, lowering kmalloc() allocated space by 50%. 2) Reduce the size of (files_struct), using a special 32 bits (or 64bits) embedded_fd_set, instead of a 1024 bits fd_set for the close_on_exec_init and open_fds_init fields. This save some ram (248 bytes per task) as most tasks dont open more than 32 files. D-Cache footprint for such tasks is also reduced to the minimum. 3) Reduce size of allocated fdset. Currently two full pages are allocated, that is 32768 bits on x86 for example, and way too much. The minimum is now L1_CACHE_BYTES. UP and SMP should benefit from this patch, because most tasks will touch only one cache line when open()/close() stdin/stdout/stderr (0/1/2), (next_fd, close_on_exec_init, open_fds_init, fd_array[0 .. 2] being in the same cache line) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: add s2ram ioctl to userland interfaceLuca Tettamanti
Add the SNAPSHOT_S2RAM ioctl to the snapshot device. This ioctl allows a userland application to make the system (previously frozen with the SNAPSHOT_FREE ioctl) enter the S3 state without freezing processes and disabling nonboot CPUs for the second time. This will allow us to implement the suspend-to-disk-and-RAM (STDR) functionality in the userland suspend tools. Signed-off-by: Luca Tettamanti <kronos.it@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: let userland tools switch console on suspendRafael J. Wysocki
Remove the console-switching code from the suspend part of the swsusp userland interface and let the userland tools switch the console. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: drain high mem pagesShaohua Li
Highmem could be in pcp list as well. Signed-off-by: Shaohua Li<shaohua.li@intel.com> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: finally solve mysqld problemRafael J. Wysocki
This patch from Pavel moves userland freeze signals handling into more logical place. It now hits even with mysqld running. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] suspend: make progress printing prettierPavel Machek
Combination of printk/pr_debug led to <7> in the middle of the line, and we printed way too many dots. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: freeze user space processes firstRafael J. Wysocki
Allow swsusp to freeze processes successfully under heavy load by freezing userspace processes before kernel threads. [Thanks to Nigel Cunningham <nigel@suspend2.net> for suggesting the way to go.] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: userland interfaceRafael J. Wysocki
This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions.  Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: documentation updatesPavel Machek
Update suspend-to-RAM documentation with new machines, and makes message when processes can't be stopped little clearer. (In one case, waiting longer actually did help). From: "Rafael J. Wysocki" <rjw@sisk.pl> Warn in the documentation that data may be lost if there are some filesystems mounted from USB devices before suspend. [Thanks to Alan Stern for providing the answer to the question in the Q:-A: part.] Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] kernel/power: move externs to header filesRandy Dunlap
Move externs from C source files to header files. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: separate swap-writing/reading codeRafael J. Wysocki
Move the swap-writing/reading code of swsusp to a separate file. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] swsusp: low level interfaceRafael J. Wysocki
Introduce the low level interface that can be used for handling the snapshot of the system memory by the in-kernel swap-writing/reading code of swsusp and the userland interface code (to be introduced shortly). Also change the way in which swsusp records the allocated swap pages and, consequently, simplifies the in-kernel swap-writing/reading code (this is necessary for the userland interface too). To this end, it introduces two helper functions in mm/swapfile.c, so that the swsusp code does not refer directly to the swap internals. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] revert "swsusp: fix breakage with swap on lvm"Andrew Morton
This was a temporary thing for 2.6.16. Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-23[PATCH] fix scheduler deadlockAnton Blanchard
We have noticed lockups during boot when stress testing kexec on ppc64. Two cpus would deadlock in scheduler code trying to grab already taken spinlocks. The double_rq_lock code uses the address of the runqueue to order the taking of multiple locks. This address is a per cpu variable: if (rq1 < rq2) { spin_lock(&rq1->lock); spin_lock(&rq2->lock); } else { spin_lock(&rq2->lock); spin_lock(&rq1->lock); } On the other hand, the code in wake_sleeping_dependent uses the cpu id order to grab locks: for_each_cpu_mask(i, sibling_map) spin_lock(&cpu_rq(i)->lock); This means we rely on the address of per cpu data increasing as cpu ids increase. While this will be true for the generic percpu implementation it may not be true for arch specific implementations. One way to solve this is to always take runqueues in cpu id order. To do this we add a cpu variable to the runqueue and check it in the double runqueue locking functions. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpcLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (78 commits) [PATCH] powerpc: Add FSL SEC node to documentation [PATCH] macintosh: tidy-up driver_register() return values [PATCH] powerpc: tidy-up of_register_driver()/driver_register() return values [PATCH] powerpc: via-pmu warning fix [PATCH] macintosh: cleanup the use of i2c headers [PATCH] powerpc: dont allow old RTC to be selected [PATCH] powerpc: make powerbook_sleep_grackle static [PATCH] powerpc: Fix warning in add_memory [PATCH] powerpc: update mailing list addresses [PATCH] powerpc: Remove calculation of io hole [PATCH] powerpc: iseries: Add bootargs to /chosen [PATCH] powerpc: iseries: Add /system-id, /model and /compatible [PATCH] powerpc: Add strne2a() to convert a string from EBCDIC to ASCII [PATCH] powerpc: iseries: Make more stuff static in platforms/iseries/mf.c [PATCH] powerpc: iseries: Remove pointless iSeries_(restart|power_off|halt) [PATCH] powerpc: iseries: mf related cleanups [PATCH] powerpc: Replace platform_is_lpar() with a firmware feature [PATCH] powerpc: trivial: Cleanup whitespace in cputable.h [PATCH] powerpc: Remove unused iommu_off logic from pSeries_init_early() [PATCH] powerpc: Unconfuse htab_bolt_mapping() callers ...
2006-03-22Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds
* master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (138 commits) [SCSI] libata: implement minimal transport template for ->eh_timed_out [SCSI] eliminate rphy allocation in favour of expander/end device allocation [SCSI] convert mptsas over to end_device/expander allocations [SCSI] allow displaying and setting of cache type via sysfs [SCSI] add scsi_mode_select to scsi_lib.c [SCSI] 3ware 9000 add big endian support [SCSI] qla2xxx: update MAINTAINERS [SCSI] scsi: move target_destroy call [SCSI] fusion - bump version [SCSI] fusion - expander hotplug suport in mptsas module [SCSI] fusion - exposing raid components in mptsas [SCSI] fusion - memory leak, and initializing fields [SCSI] fusion - exclosure misspelled [SCSI] fusion - cleanup mptsas event handling functions [SCSI] fusion - removing target_id/bus_id from the VirtDevice structure [SCSI] fusion - static fix's [SCSI] fusion - move some debug firmware event debug msgs to verbose level [SCSI] fusion - loginfo header update [SCSI] add scsi_reprobe_device [SCSI] megaraid_sas: fix extended timeout handling ...
2006-03-22[PATCH] on_each_cpu(): disable local interruptsAndrew Morton
When on_each_cpu() runs the callback on other CPUs, it runs with local interrupts disabled. So we should run the function with local interrupts disabled on this CPU, too. And do the same for UP, so the callback is run in the same environment on both UP and SMP. (strictly it should do preempt_disable() too, but I think local_irq_disable is sufficiently equivalent). Also uninlines on_each_cpu(). softirq.c was the most appropriate file I could find, but it doesn't seem to justify creating a new file. Oh, and fix up that comment over (under?) x86's smp_call_function(). It drives me nuts. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] unshare: Error if passed unsupported flagsEric W. Biederman
A bare bones trivial patch to ensure we always get -EINVAL on the unsupported cases for sys_unshare. If this goes in before 2.6.16 it allows us to forward compatible with future applications using sys_unshare. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: JANAK DESAI <janak@us.ibm.com> Cc: <stable@kerenl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] sched: remove sleep_avg multiplierMike Galbraith
Remove the sleep_avg multiplier. This multiplier was necessary back when we had 10 seconds of dynamic range in sleep_avg, but now that we only have one second, it causes that one second to be compressed down to 100ms in some cases. This is particularly noticeable when compiling a kernel in a slow NFS mount, and I believe it to be a very likely candidate for other recently reported network related interactivity problems. In testing, I can detect no negative impact of this removal. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-21Merge ../linux-2.6James Bottomley
2006-03-20[PATCH] fix module sysfs files reference countingGreg Kroah-Hartman
The module files, refcnt, version, and srcversion did not properly increment the owner's module reference count, allowing the modules to be removed while the files were open, causing oopses. This patch fixes this, and also fixes the problem that the version and srcversion files were not showing up, unless CONFIG_MODULE_UNLOAD was enabled, which is not correct. Cc: Nathan Lynch <ntl@pobox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20[PATCH] add EXPORT_SYMBOL_GPL_FUTURE() to RCU subsystemGreg Kroah-Hartman
As the RCU symbols are going to be changed to GPL in the near future, lets warn users that this is going to happen. Cc: Paul McKenney <paulmck@us.ibm.com> Acked-by: Dipankar Sarma <dipankar@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20[PATCH] add EXPORT_SYMBOL_GPL_FUTURE()Greg Kroah-Hartman
This patch adds the ability to mark symbols that will be changed in the future, so that kernel modules that don't include MODULE_LICENSE("GPL") and use the symbols, will be flagged and printed out to the system log. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20[PATCH] Clean up module.c symbol searching logicSam Ravnborg
Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20[PATCH] kobject: fix build error if CONFIG_SYSFS=nJun'ichi Nomura
Moving uevent_seqnum and uevent_helper to kobject_uevent.c because they are used even if CONFIG_SYSFS=n while kernel/ksysfs.c is built only if CONFIG_SYSFS=y, Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-18[PATCH] don't do exit_io_context() until we know we won't be doing any IOAl Viro
testcase: mount /dev/sdb10 /mnt touch /mnt/tmp/b umount /mnt mount /dev/sdb10 /mnt rm /mnt/tmp/b </mnt/tmp/b umount /mnt and watch blkdev_ioc line in /proc/slabinfo. Vanilla kernel leaks. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-03-18[PATCH] disable unshare(CLONE_VM) for nowOleg Nesterov
sys_unshare() does mmput(new_mm). This is not enough if we have mm->core_waiters. This patch is a temporary fix for soon to be released 2.6.16. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> [ Checked with Uli: "I'm not planning to use unshare(CLONE_VM). It's not needed for any functionality planned so far. What we (as in Red Hat) need unshare() for now is the filesystem side." ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] posix-timers: fix requeue accounting when signal is ignoredRoman Zippel
When the posix-timer signal is ignored then the timer is rearmed by the callback function. The requeue pending accounting has to be fixed up else the state might be wrong. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] time_interpolator: add __read_mostlyChristoph Lameter
The pointer to the current time interpolator and the current list of time interpolators are typically only changed during bootup. Adding __read_mostly takes them away from possibly hot cachelines. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17[PATCH] unshare: Use rcu_assign_pointer when setting sighandEric W. Biederman
The sighand pointer only needs the rcu_read_lock on the read side. So only depending on task_lock protection when setting this pointer is not enough. We also need a memory barrier to ensure the initialization is seen first. Use rcu_assign_pointer as it does this for us, and clearly documents that we are setting an rcu readable pointer. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-17Merge ../linux-2.6Paul Mackerras
2006-03-14Merge ../linux-2.6James Bottomley
2006-03-14[PATCH] Fix sigaltstack corruption among cloned threadsGOTO Masanori
This patch fixes alternate signal stack corruption among cloned threads with CLONE_SIGHAND (and CLONE_VM) for linux-2.6.16-rc6. The value of alternate signal stack is currently inherited after a call of clone(... CLONE_SIGHAND | CLONE_VM). But if sigaltstack is set by a parent thread, and then if multiple cloned child threads (+ parent threads) call signal handler at the same time, some threads may be conflicted - because they share to use the same alternative signal stack region. Finally they get sigsegv. It's an undesirable race condition. Note that child threads created from NPTL pthread_create() also hit this conflict when the parent thread uses sigaltstack, without my patch. To fix this problem, this patch clears the child threads' sigaltstack information like exec(). This behavior follows the SUSv3 specification. In SUSv3, pthread_create() says "The alternate stack shall not be inherited (when new threads are initialized)". It means that sigaltstack should be cleared when sigaltstack memory space is shared by cloned threads with CLONE_SIGHAND. Note that I chose "if (clone_flags & CLONE_SIGHAND)" line because: - If clone_flags line is not existed, fork() does not inherit sigaltstack. - CLONE_VM is another choice, but vfork() does not inherit sigaltstack. - CLONE_SIGHAND implies CLONE_VM, and it looks suitable. - CLONE_THREAD is another candidate, and includes CLONE_SIGHAND + CLONE_VM, but this flag has a bit different semantics. I decided to use CLONE_SIGHAND. [ Changed to test for CLONE_VM && !CLONE_VFORK after discussion --Linus ] Signed-off-by: GOTO Masanori <gotom@sanori.org> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Acked-by: Linus Torvalds <torvalds@osdl.org> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-11[PATCH] remove __put_task_struct_cb export againChristoph Hellwig
The patch '[PATCH] RCU signal handling' [1] added an export for __put_task_struct_cb, a put_task_struct helper newly introduced in that patch. But the put_task_struct couldn't be used modular previously as __put_task_struct wasn't exported. There are not callers of it in modular code, and it shouldn't be exported because we don't want drivers to hold references to task_structs. This patch removes the export and folds __put_task_struct into __put_task_struct_cb as there's no other caller. [1] http://www2.kernel.org/git/gitweb.cgi?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=e56d090310d7625ecb43a1eeebd479f04affb48b Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-09Merge ../linux-2.6Paul Mackerras
2006-03-08[PATCH] fix file countingDipankar Sarma
I have benchmarked this on an x86_64 NUMA system and see no significant performance difference on kernbench. Tested on both x86_64 and powerpc. The way we do file struct accounting is not very suitable for batched freeing. For scalability reasons, file accounting was constructor/destructor based. This meant that nr_files was decremented only when the object was removed from the slab cache. This is susceptible to slab fragmentation. With RCU based file structure, consequent batched freeing and a test program like Serge's, we just speed this up and end up with a very fragmented slab - llm22:~ # cat /proc/sys/fs/file-nr 587730 0 758844 At the same time, I see only a 2000+ objects in filp cache. The following patch I fixes this problem. This patch changes the file counting by removing the filp_count_lock. Instead we use a separate percpu counter, nr_files, for now and all accesses to it are through get_nr_files() api. In the sysctl handler for nr_files, we populate files_stat.nr_files before returning to user. Counting files as an when they are created and destroyed (as opposed to inside slab) allows us to correctly count open files with RCU. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] rcu batch tuningDipankar Sarma
This patch adds new tunables for RCU queue and finished batches. There are two types of controls - number of completed RCU updates invoked in a batch (blimit) and monitoring for high rate of incoming RCUs on a cpu (qhimark, qlowmark). By default, the per-cpu batch limit is set to a small value. If the input RCU rate exceeds the high watermark, we do two things - force quiescent state on all cpus and set the batch limit of the CPU to INTMAX. Setting batch limit to INTMAX forces all finished RCUs to be processed in one shot. If we have more than INTMAX RCUs queued up, then we have bigger problems anyway. Once the incoming queued RCUs fall below the low watermark, the batch limit is set to the default. Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08[PATCH] idle threads should have a sane ->timestamp valueIngo Molnar
Idle threads should have a sane ->timestamp value, to avoid init kernel thread(s) from inheriting it and causing miscalculations in try_to_wake_up(). Reported-by: Mike Galbraith <efault@gmx.de>. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>