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* [PATCH] Module per-cpu alignment cannot always be metRusty Russell2005-08-02
| | | | | | | | | | | | | | | | | | | The module code assumes noone will ever ask for a per-cpu area more than SMP_CACHE_BYTES aligned. However, as these cases show, gcc asks sometimes asks for 32-byte alignment for the per-cpu section on a module, and if CONFIG_X86_L1_CACHE_SHIFT is 4, we hit that BUG_ON(). This is obviously an unusual combination, as there have been few reports, but better to warn than die. See: http://www.ussg.iu.edu/hypermail/linux/kernel/0409.0/0768.html And more recently: http://bugs.gentoo.org/show_bug.cgi?id=97006 Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] remove sys_set_zone_reclaim()Ingo Molnar2005-08-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This removes sys_set_zone_reclaim() for now. While i'm sure Martin is trying to solve a real problem, we must not hard-code an incomplete and insufficient approach into a syscall, because syscalls are pretty much for eternity. I am quite strongly convinced that this syscall must not hit v2.6.13 in its current form. Firstly, the syscall lacks basic syscall design: e.g. it allows the global setting of VM policy for unprivileged users. (!) [ Imagine an Oracle installation and a SAP installation on the same NUMA box fighting over the 'optimal' setting for this flag. What will they do? Will they try to set the flag to their own preferred value every second or so? ] Secondly, it was added based on a single datapoint from Martin: http://marc.theaimsgroup.com/?l=linux-mm&m=111763597218177&w=2 where Martin characterizes the numbers the following way: ' Run-to-run variability for "make -j" is huge, so these numbers aren't terribly useful except to see that with reclaim the benchmark still finishes in a reasonable amount of time. ' in other words: the fundamental problem has likely not been solved, only a tendential move into the right direction has been observed, and a handful of numbers were picked out of a set of hugely variable results, without showing the variability data. How much variance is there run-to-run? I'd really suggest to first walk the walk and see what's needed to get stable & predictable kernel compilation numbers on that NUMA box, before adding random syscalls to tune a particular aspect of the VM ... which approach might not even matter once the whole picture has been analyzed and understood! The third, most important point is that the syscall exposes VM tuning internals in a completely unstructured way. What sense does it make to have a _GLOBAL_ per-node setting for 'should we go to another node for reclaim'? If then it might make sense to do this per-app, via numalib or so. The change is minimalistic in that it doesnt remove the syscall and the underlying infrastructure changes, only the user-visible changes. We could perhaps add a CAP_SYS_ADMIN-only sysctl for this hack, a'ka /proc/sys/vm/swappiness, but even that looks quite counterproductive when the generic approach is that we are trying to reduce the number of external factors in the VM balance picture. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] revert bogus softirq changesAndrew Morton2005-07-30
| | | | | | | | | This snuck in with an x86_64 change. Thanks to Richard Purdie <rpurdie@rpsys.net> for spotting it. Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] reboot: remove device_suspend(PMSG_FREEZE) from kernel_kexecEric W. Biederman2005-07-29
| | | | | | | | | If device_suspend(PMSG_FREEZE) is not ready to be called in kernel_restart it is definitely not ready to be called in the even more fickle kernel_kexec. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] posix timers: fix normalization problemGeorge Anzinger2005-07-29
| | | | | | | | | | | | | | | | | | | | | | | (We found this (after a customer complained) and it is in the kernel.org kernel. Seems that for CLOCK_MONOTONIC absolute timers and clock_nanosleep calls both the request time and wall_to_monotonic are subtracted prior to the normalize resulting in an overflow in the existing normalize test. This causes the result to be shifted ~4 seconds ahead instead of ~2 seconds back in time.) The normalize code in posix-timers.c fails when the tv_nsec member is ~1.2 seconds negative. This can happen on absolute timers (and clock_nanosleeps) requested on CLOCK_MONOTONIC (both the request time and wall_to_monotonic are subtracted resulting in the possibility of a number close to -2 seconds.) This fix uses the set_normalized_timespec() (which does not have an overflow problem) to fix the problem and as a side effect makes the code cleaner. Signed-off-by: George Anzinger <george@mvista.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86_64: Switch to the interrupt stack when running a softirq in ↵Andi Kleen2005-07-29
| | | | | | | | | | | | | local_bh_enable() This avoids some potential stack overflows with very deep softirq callchains. i386 does this too. TOADD CFI annotation Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Avoid device suspend on rebootAndrew Morton2005-07-27
| | | | | | | My fairly ordinary x86 test box gets stuck during reboot on the wait_for_completion() in ide_do_drive_cmd(): Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] clean up inline static vs static inlineJesper Juhl2005-07-27
| | | | | | | | | | | | | | | `gcc -W' likes to complain if the static keyword is not at the beginning of the declaration. This patch fixes all remaining occurrences of "inline static" up with "static inline" in the entire kernel tree (140 occurrences in 47 files). While making this change I came across a few lines with trailing whitespace that I also fixed up, I have also added or removed a blank line or two here and there, but there are no functional changes in the patch. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/crash_dump.c: add kerneldocRandy Dunlap2005-07-27
| | | | | | | | Add kerneldoc to kernel/crash_dump.c Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/cpuset.c: add kerneldoc, fix typosRandy Dunlap2005-07-27
| | | | | | | | | | | Add kerneldoc to kernel/cpuset.c Fix cpuset typos in init/Kconfig Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/capability.c: add kerneldocRandy Dunlap2005-07-27
| | | | | | | | Add kerneldoc to kernel/capability.c Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] s390: spin lock retryMartin Schwidefsky2005-07-27
| | | | | | | | | | | | | | | | | Split spin lock and r/w lock implementation into a single try which is done inline and an out of line function that repeatedly tries to get the lock before doing the cpu_relax(). Add a system control to set the number of retries before a cpu is yielded. The reason for the spin lock retry is that the diagnose 0x44 that is used to give up the virtual cpu is quite expensive. For spin locks that are held only for a short period of time the costs of the diagnoses outweights the savings for spin locks that are held for a longer timer. The default retry count is 1000. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] itimer fixesGeorge Anzinger2005-07-27
| | | | | | | | | | | | | Fix the recent off-by-one fix in the itimer code: 1. The repeating timer is figured using the requested time (not +1 as we know where we are in the jiffie). 2. The tests for interval too large are left to the time_val to jiffie code. Signed-off-by: George Anzinger <george@mvista.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Address BUG: using smp_processor_id() in preemptible [00000001] codeNigel Cunningham2005-07-27
| | | | | | | | | | This patch fixes a warning in the disable_nonboot_cpus call in kernel/power/smp.c. Signed-off by: Nigel Cunningham <nigel@suspend2.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] fix MAX_USER_RT_PRIO and MAX_RT_PRIOSteven Rostedt2005-07-26
| | | | | | | | | | | | | Here's the patch again to fix the code to handle if the values between MAX_USER_RT_PRIO and MAX_RT_PRIO are different. Without this patch, an SMP system will crash if the values are different. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Dean Nelson <dcn@sgi.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Fix RLIMIT_RTPRIO breakageAndreas Steinmetz2005-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | RLIMIT_RTPRIO is supposed to grant non privileged users the right to use SCHED_FIFO/SCHED_RR scheduling policies with priorites bounded by the RLIMIT_RTPRIO value via sched_setscheduler(). This is usually used by audio users. Unfortunately this is broken in 2.6.13rc3 as you can see in the excerpt from sched_setscheduler below: /* * Allow unprivileged RT tasks to decrease priority: */ if (!capable(CAP_SYS_NICE)) { /* can't change policy */ if (policy != p->policy) return -EPERM; After the above unconditional test which causes sched_setscheduler to fail with no regard to the RLIMIT_RTPRIO value the following check is made: /* can't increase priority */ if (policy != SCHED_NORMAL && param->sched_priority > p->rt_priority && param->sched_priority > p->signal->rlim[RLIMIT_RTPRIO].rlim_cur) return -EPERM; Thus I do believe that the RLIMIT_RTPRIO value must be taken into account for the policy check, especially as the RLIMIT_RTPRIO limit is of no use without this change. The attached patch fixes this problem. Signed-off-by: Andreas Steinmetz <ast@domdv.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swpsuspend: Have suspend to disk use factors of sys_rebootEric W. Biederman2005-07-26
| | | | | | | | | The suspend to disk code was a poor copy of the code in sys_reboot now that we have kernel_power_off, kernel_restart and kernel_halt use them instead of poorly duplicating them inline. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Call emergency_reboot from panicEric W. Biederman2005-07-26
| | | | | | | | We know the system is in trouble so there is no question if this is an emergecy :) Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Use kernel_power_off in sysrq-oEric W. Biederman2005-07-26
| | | | | | | | | | | | We already do all of the gymnastics to run from process context to call the power off code so call into the power off code cleanly. This especially helps acpi as part of it's shutdown logic should run acpi_shutdown called from device_shutdown which was not being called from here. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add emergency_restart()Eric W. Biederman2005-07-26
| | | | | | | | | | | | | | | | | | When the kernel is working well and we want to restart cleanly kernel_restart is the function to use. But in many instances the kernel wants to reboot when thing are expected to be working very badly such as from panic or a software watchdog handler. This patch adds the function emergency_restart() so that callers can be clear what semantics they expect when calling restart. emergency_restart() is expected to be callable from interrupt context and possibly reliable in even more trying circumstances. This is an initial generic implementation for all architectures. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Make ctrl_alt_del call kernel_restart to get a proper reboot.Eric W. Biederman2005-07-26
| | | | | | | | | It is obvious we wanted to call kernel_restart here but since we don't have it the code was expanded inline and hasn't been correct since sometime in 2.4. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Refactor sys_reboot into reusable partsEric W. Biederman2005-07-26
| | | | | | | | | | | Because the factors of sys_reboot don't exist people calling into the reboot path duplicate the code badly, leading to inconsistent expectations of code in the reboot path. This patch should is just code motion. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Add missing device_suspsend(PMSG_FREEZE) calls.Eric W. Biederman2005-07-26
| | | | | | | | In the recent addition of device_suspend calls into sys_reboot two code paths were missed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] inotify: move sysctlRobert Love2005-07-13
| | | | | | | | This moves the inotify sysctl knobs to "/proc/sys/fs/inotify" from "/proc/sys/fs". Also some related cleanup. Signed-off-by: Robert Love <rml@novell.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] inotifyRobert Love2005-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inotify is intended to correct the deficiencies of dnotify, particularly its inability to scale and its terrible user interface: * dnotify requires the opening of one fd per each directory that you intend to watch. This quickly results in too many open files and pins removable media, preventing unmount. * dnotify is directory-based. You only learn about changes to directories. Sure, a change to a file in a directory affects the directory, but you are then forced to keep a cache of stat structures. * dnotify's interface to user-space is awful. Signals? inotify provides a more usable, simple, powerful solution to file change notification: * inotify's interface is a system call that returns a fd, not SIGIO. You get a single fd, which is select()-able. * inotify has an event that says "the filesystem that the item you were watching is on was unmounted." * inotify can watch directories or files. Inotify is currently used by Beagle (a desktop search infrastructure), Gamin (a FAM replacement), and other projects. See Documentation/filesystems/inotify.txt. Signed-off-by: Robert Love <rml@novell.com> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Merge master.kernel.org:/pub/scm/linux/kernel/git/lenb/linux-2.6Linus Torvalds2005-07-12
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| * [ACPI] merge acpi-2.6.12 branch into latest Linux 2.6.13-rc...Len Brown2005-07-12
| |\ | | | | | | | | | Signed-off-by: Len Brown <len.brown@intel.com>
| | * [ACPI] Suspend to RAM fixDavid Shaohua Li2005-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Free some RAM before entering S3 so that upon resume we can be sure early allocations will succeed. http://bugzilla.kernel.org/show_bug.cgi?id=3469 Signed-off-by: David Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
| | * [ACPI] ACPI poweroff fixAlexey Starikovskiy2005-07-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Register an "acpi" system device to be notified of shutdown preparation. This depends on CONFIG_PM http://bugzilla.kernel.org/show_bug.cgi?id=4041 Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Len Brown <len.brown@intel.com>
* | | [PATCH] lower VM_DONTCOPY total_vmHugh Dickins2005-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | dup_mmap of a VM_DONTCOPY vma forgot to lower the child's total_vm. (But no way does this account for the recent report of total_vm seen too low.) Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] name_to_dev_t warning fixAndrew Morton2005-07-12
|/ / | | | | | | | | | | | | | | kernel/power/disk.c needs a declaration of name_to_dev_t() in scope. mount.h seems like an appropriate choice. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] cond_resched(): fix bogus might_sleep() warningIngo Molnar2005-07-07
| | | | | | | | | | | | | | | | | | | | The BKS might be reacquired before we have dropped PREEMPT_ACTIVE, which could trigger a second could trigger a second cond_resched() call. Bug found by Hirofumi Ogawa. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] mostly_read data sectionChristoph Lameter2005-07-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new section called ".data.read_mostly" for data items that are read frequently and rarely written to like cpumaps etc. If these maps are placed in the .data section then these frequenly read items may end up in cachelines with data is is frequently updated. In that case all processors in an SMP system must needlessly reload the cachelines again and again containing elements of those frequently used variables. The ability to share these cachelines will allow each cpu in an SMP system to keep local copies of those shared cachelines thereby optimizing performance. Signed-off-by: Alok N Kataria <alokk@calsoftinc.com> Signed-off-by: Shobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: Christoph Lameter <christoph@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>
* | [PATCH] pm: clean up process.cPavel Machek2005-07-07
| | | | | | | | | | | | | | | | | | freezeable() already tests for TRACED/STOPPED processes, no need to do it twice. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] swsusp: fix error handlingPavel Machek2005-07-07
| | | | | | | | | | | | | | | | | | Fix error handling and whitespace in swsusp.c. swsusp_free() was called when there was nothing allocating, leading to oops. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] pm: Fix resume from initrdPavel Machek2005-07-07
| | | | | | | | | | | | | | | | | | Move device name resolution code around so that it is not called from resume-from-initrd. name_to_dev_t may be unavailable at that point. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] kprobes: fix namespace problem and sparc64 buildRusty Lynch2005-07-05
| | | | | | | | | | | | | | | | | | | | | | | | The following renames arch_init, a kprobes function for performing any architecture specific initialization, to arch_init_kprobes in order to cleanup the namespace. Also, this patch adds arch_init_kprobes to sparc64 to fix the sparc64 kprobes build from the last return probe patch. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] irqpollAlan Cox2005-06-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Anyone reporting a stuck IRQ should try these options. Its effectiveness varies we've found in the Fedora case. Quite a few systems with misdescribed IRQ routing just work when you use irqpoll. It also fixes up the VIA systems although thats now fixed with the VIA quirk (which we could just make default as its what Redmond OS does but Linus didn't like it historically). A small number of systems have jammed IRQ sources or misdescribes that cause an IRQ that we have no handler registered anywhere for. In those cases it doesn't help. Signed-off-by: Alan Cox <number6@the-village.bc.nu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] ITIMER_REAL: fix possible deadlock and raceOleg Nesterov2005-06-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Steven Rostedt pointed out, there are 2 problems with ITIMER_REAL timers. 1. do_setitimer() does not call del_timer_sync() in case when the timer is not pending (it_real_value() returns 0). This is wrong, the timer may still be running, and it can rearm itself. 2. It calls del_timer_sync() with tsk->sighand->siglock held. This is deadlockable, because timer's handler needs this lock too. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Using msleep() instead of HZLuca Falavigna2005-06-29
| | | | | | | | | | | | | | | | | | | | Use msleep() in a few places. Signed-off-by: Luca Falavigna <dktrkranz@gmail.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeff Garzik <jgarzik@pobox.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Tweak idle thread setup semanticsIngo Molnar2005-06-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch tweaks idle thread setup semantics a bit: instead of setting NEED_RESCHED in init_idle(), we do an explicit schedule() before calling into cpu_idle(). This patch, while having no negative side-effects, enables wider use of cond_resched()s. (which might happen in the stock kernel too, but it's particulary important for voluntary-preempt) Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] kexec: fix sparse warningsAlexey Dobriyan2005-06-28
| | | | | | | | | | | | | | Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Return probe redesign: architecture independent changesRusty Lynch2005-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following is the second version of the function return probe patches I sent out earlier this week. Changes since my last submission include: * Fix in ppc64 code removing an unneeded call to re-enable preemption * Fix a build problem in ia64 when kprobes was turned off * Added another BUG_ON check to each of the architecture trampoline handlers My initial patch description ==> From my experiences with adding return probes to x86_64 and ia64, and the feedback on LKML to those patches, I think we can simplify the design for return probes. The following patch tweaks the original design such that: * Instead of storing the stack address in the return probe instance, the task pointer is stored. This gives us all we need in order to: - find the correct return probe instance when we enter the trampoline (even if we are recursing) - find all left-over return probe instances when the task is going away This has the side effect of simplifying the implementation since more work can be done in kernel/kprobes.c since architecture specific knowledge of the stack layout is no longer required. Specifically, we no longer have: - arch_get_kprobe_task() - arch_kprobe_flush_task() - get_rp_inst_tsk() - get_rp_inst() - trampoline_post_handler() <see next bullet> * Instead of splitting the return probe handling and cleanup logic across the pre and post trampoline handlers, all the work is pushed into the pre function (trampoline_probe_handler), and then we skip single stepping the original function. In this case the original instruction to be single stepped was just a NOP, and we can do without the extra interruption. The new flow of events to having a return probe handler execute when a target function exits is: * At system initialization time, a kprobe is inserted at the beginning of kretprobe_trampoline. kernel/kprobes.c use to handle this on it's own, but ia64 needed to do this a little differently (i.e. a function pointer is really a pointer to a structure containing the instruction pointer and a global pointer), so I added the notion of arch_init(), so that kernel/kprobes.c:init_kprobes() now allows architecture specific initialization by calling arch_init() before exiting. Each architecture now registers a kprobe on it's own trampoline function. * register_kretprobe() will insert a kprobe at the beginning of the targeted function with the kprobe pre_handler set to arch_prepare_kretprobe (still no change) * When the target function is entered, the kprobe is fired, calling arch_prepare_kretprobe (still no change) * In arch_prepare_kretprobe() we try to get a free instance and if one is available then we fill out the instance with a pointer to the return probe, the original return address, and a pointer to the task structure (instead of the stack address.) Just like before we change the return address to the trampoline function and mark the instance as used. If multiple return probes are registered for a given target function, then arch_prepare_kretprobe() will get called multiple times for the same task (since our kprobe implementation is able to handle multiple kprobes at the same address.) Past the first call to arch_prepare_kretprobe, we end up with the original address stored in the return probe instance pointing to our trampoline function. (This is a significant difference from the original arch_prepare_kretprobe design.) * Target function executes like normal and then returns to kretprobe_trampoline. * kprobe inserted on the first instruction of kretprobe_trampoline is fired and calls trampoline_probe_handler() (no change here) * trampoline_probe_handler() consumes each of the instances associated with the current task by calling the registered handler function and marking the instance as unused until an instance is found that has a return address different then the trampoline function. (change similar to my previous ia64 RFC) * If the task is killed with some left-over return probe instances (meaning that a target function was entered, but never returned), then we just free any instances associated with the task. (Not much different other then we can handle this without calling architecture specific functions.) There is a known problem that this patch does not yet solve where registering a return probe flush_old_exec or flush_thread will put us in a bad state. Most likely the best way to handle this is to not allow registering return probes on these two functions. (Significant change) This patch series applies to the 2.6.12-rc6-mm1 kernel, and provides: * kernel/kprobes.c changes * i386 patch of existing return probes implementation * x86_64 patch of existing return probe implementation * ia64 implementation * ppc64 implementation (provided by Ananth) This patch implements the architecture independant changes for a reworking of the kprobes based function return probes design. Changes include: * Removing functions for querying a return probe instance off a stack address * Removing the stack_addr field from the kretprobe_instance definition, and adding a task pointer * Adding architecture specific initialization via arch_init() * Removing extern definitions for the architecture trampoline functions (this isn't needed anymore since the architecture handles the initialization of the kprobe in the return probe trampoline function.) Signed-off-by: Rusty Lynch <rusty.lynch@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] kprobes: fix single-step out of line - take2Ananth N Mavinakayanahalli2005-06-27
| | | | | | | | | | | | | | | | | | | | | | Now that PPC64 has no-execute support, here is a second try to fix the single step out of line during kprobe execution. Kprobes on x86_64 already solved this problem by allocating an executable page and using it as the scratch area for stepping out of line. Reuse that. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | [PATCH] Update cfq io scheduler to time sliced designJens Axboe2005-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | Merge Christoph's freeze cleanup patchLinus Torvalds2005-06-25
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| * | [PATCH] Cleanup patch for process freezingChristoph Lameter2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] Use ALIGN to remove duplicate codeNick Wilson2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | This patch makes use of ALIGN() to remove duplicate round-up code. Signed-off-by: Nick Wilson <njw@osdl.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] remove redundant NULL check before before kfree() in kernel/sysctl.cJesper Juhl2005-06-25
| | | | | | | | | | | | | | | | | | Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* | | [PATCH] kernel/timer: fix msleep_interruptible() commentDomen Puncer2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comment for msleep_interruptible() is wrong, as it will ignore wait-queue events, but will wake up early for signals. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Domen Puncer <domen@coderock.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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