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2006-04-20Merge branch 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
* 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block: [PATCH] block/elevator.c: remove unused exports [PATCH] splice: fix smaller sized splice reads [PATCH] Don't inherit ->splice_pipe across forks [patch] cleanup: use blk_queue_stopped [PATCH] Document online io scheduler switching
2006-04-20[PATCH] kprobes: NULL out non-relevant fields in struct kretprobeAnanth N Mavinakayanahalli
In cases where a struct kretprobe's *_handler fields are non-NULL, it is possible to cause a system crash, due to the possibility of calls ending up in zombie functions. Documentation clearly states that unused *_handlers should be set to NULL, but kprobe users sometimes fail to do so. Fix it by setting the non-relevant fields of the struct kretprobe to NULL. Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-20[PATCH] Don't inherit ->splice_pipe across forksJens Axboe
It's really task private, so clear that field on fork after copying task structure. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-04-19[PATCH] Add more prevent_tail_call()OGAWA Hirofumi
Those also break userland regs like following. 00000000 <sys_chown16>: 0: 0f b7 44 24 0c movzwl 0xc(%esp),%eax 5: 83 ca ff or $0xffffffff,%edx 8: 0f b7 4c 24 08 movzwl 0x8(%esp),%ecx d: 66 83 f8 ff cmp $0xffffffff,%ax 11: 0f 44 c2 cmove %edx,%eax 14: 66 83 f9 ff cmp $0xffffffff,%cx 18: 0f 45 d1 cmovne %ecx,%edx 1b: 89 44 24 0c mov %eax,0xc(%esp) 1f: 89 54 24 08 mov %edx,0x8(%esp) 23: e9 fc ff ff ff jmp 24 <sys_chown16+0x24> where the tailcall at the end overwrites the incoming stack-frame. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> [ I would _really_ like to have a way to tell gcc about calling conventions. The "prevent_tail_call()" macro is pretty ugly ] Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-19[PATCH] swsusp: prevent possible image corruption on resumeRafael J. Wysocki
The function free_pagedir() used by swsusp for freeing its internal data structures clears the PG_nosave and PG_nosave_free flags for each page being freed. However, during resume PG_nosave_free set means that the page in question is "unsafe" (ie. it will be overwritten in the process of restoring the saved system state from the image), so it should not be used for the image data. Therefore free_pagedir() should not clear PG_nosave_free if it's called during resume (otherwise "unsafe" pages freed by it may be used for storing the image data and the data may get corrupted later on). 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>
2006-04-19[PATCH] task: Make task list manipulations RCU safeEric W. Biederman
While we can currently walk through thread groups, process groups, and sessions with just the rcu_read_lock, this opens the door to walking the entire task list. We already have all of the other RCU guarantees so there is no cost in doing this, this should be enough so that proc can stop taking the tasklist lock during readdir. prev_task was killed because it has no users, and using it will miss new tasks when doing an rcu traversal. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-14[PATCH] kill unushed __put_task_struct_cbEric W. Biederman
Somehow in the midst of dotting i's and crossing t's during the merge up to rc1 we wound up keeping __put_task_struct_cb when it should have been killed as it no longer has any users. Sorry I probably should have caught this while it was still in the -mm tree. Having the old code there gets confusing when reading through the code and trying to understand what is happening. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-14[PATCH] remove kernel/power/pm.c:pm_unregister()Adrian Bunk
Since the last user is removed in -mm, we can now remove this long deprecated function. Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-04-14[PATCH] fix non-leader exec under ptraceRoland McGrath
This reverts most of commit 30e0fca6c1d7d26f3f2daa4dd2b12c51dadc778a. It broke the case of non-leader MT exec when ptraced. I think the bug it was intended to fix was already addressed by commit 788e05a67c343fa22f2ae1d3ca264e7f15c25eaf. Signed-off-by: Roland McGrath <roland@redhat.com> Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] __group_complete_signal: remove bogus BUG_ONOleg Nesterov
Commit e56d090310d7625ecb43a1eeebd479f04affb48b [PATCH] RCU signal handling made this BUG_ON() unsafe. This code runs under ->siglock, while switch_exec_pids() takes tasklist_lock. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-blockLinus Torvalds
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block: [PATCH] vfs: add splice_write and splice_read to documentation [PATCH] Remove sys_ prefix of new syscalls from __NR_sys_* [PATCH] splice: warning fix [PATCH] another round of fs/pipe.c cleanups [PATCH] splice: comment styles [PATCH] splice: add Ingo as addition copyright holder [PATCH] splice: unlikely() optimizations [PATCH] splice: speedups and optimizations [PATCH] pipe.c/fifo.c code cleanups [PATCH] get rid of the PIPE_*() macros [PATCH] splice: speedup __generic_file_splice_read [PATCH] splice: add direct fd <-> fd splicing support [PATCH] splice: add optional input and output offsets [PATCH] introduce a "kernel-internal pipe object" abstraction [PATCH] splice: be smarter about calling do_page_cache_readahead() [PATCH] splice: optimize the splice buffer mapping [PATCH] splice: cleanup __generic_file_splice_read() [PATCH] splice: only call wake_up_interruptible() when we really have to [PATCH] splice: potential !page dereference [PATCH] splice: mark the io page as accessed
2006-04-11[PATCH] add cpu_relax to hrtimer_cancelJoe Korty
Add a cpu_relax() to the hand-coded spinwait in hrtimer_cancel(). Signed-off-by: Joe Korty <joe.korty@ccur.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] build kernel/irq/migration.c only if CONFIG_GENERIC_PENDING_IRQ is setChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] the scheduled unexport of panic_timeoutAdrian Bunk
Implement the scheduled unexport of panic_timeout. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] timer initialisation fixAndrew Morton
We need the boot CPU's tvec_bases[] entry to be initialised super-early in boot, for early_serial_setup(). That runs within setup_arch(), before even per-cpu areas are initialised. The patch changes tvec_bases to use compile-time initialisation, and adds a separate array `tvec_base_done' to keep track of which CPU has had its tvec_bases[] entry initialised (because we can no longer use the zeroness of that tvec_bases[] entry to determine whether it has been initialised). Thanks to Eugene Surovegin <ebs@ebshome.net> for diagnosing this. Cc: Eugene Surovegin <ebs@ebshome.net> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] frv: define MMU mode specific syscalls as 'cond_syscall' and clean ↵Hyok S. Choi
up unneeded macros For some architectures, a few syscalls are not linked in noMMU mode. In that case, the MMU depending syscalls are needed to be defined as 'cond_syscall'. For example, ARM architecture selectively links sys_mlock by the mode configuration. In case of FRV, it has been managed by #ifdef CONFIG_MMU macro in arch/frv/kernel/entry.S. However these conditional macros are just duplicates if they were defined as cond_syscall. Compilation test is done with FRV toolchains for both of MMU and noMMU mode. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] sched: don't awaken RT tasks on expired arrayMike Galbraith
RT tasks are being awakened on the expired array when expired_starving() is true, whereas they really should be excluded. Fix. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] sched: fix interactive task starvationMike Galbraith
Fix a starvation problem that occurs when a stream of highly interactive tasks delay an array switch for extended periods despite EXPIRED_STARVING(rq) being true. AFAIKT, the only choice is to enqueue awakening tasks on the expired array in this case. Without this patch, it can be nearly impossible to remotely login to a busy server, and interactive shell commands can starve for minutes. Also, convert the EXPIRED_STARVING macro into an inline function which humans can understand. Signed-off-by: Mike Galbraith <efault@gmx.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11[PATCH] splice: add direct fd <-> fd splicing supportJens Axboe
It's more efficient for sendfile() emulation. Basically we cache an internal private pipe and just use that as the intermediate area for pages. Direct splicing is not available from sys_splice(), it is only meant to be used for sendfile() emulation. Additional patch from Ingo Molnar to avoid the PIPE_BUFFERS loop at exit for the normal fast path. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-04-09[PATCH] x86_64: Fix drift with HPET timer enabledJordan Hargrave
If the HPET timer is enabled, the clock can drift by ~3 seconds a day. This is due to the HPET timer not being initialized with the correct setting (still using PIT count). If HZ changes, this drift can become even more pronounced. HPET patch initializes tick_nsec with correct tick_nsec settings for HPET timer. Vojtech comments: "It's not entirely correct (it assumes the HPET ticks totally exactly), but it's significantly better than assuming the PIT error there." Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-02BUG_ON() Conversion in kernel/signal.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-02BUG_ON() Conversion in kernel/signal.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-02BUG_ON() Conversion in kernel/ptrace.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01Fix comments: s/granuality/granularity/Kalin KOZHUHAROV
I was grepping through the code and some `grep ganularity -R .` didn't catch what I thought. Then looking closer I saw the term "granuality" used in only four places (in comments) and granularity in many more places describing the same idea. Some other facts: dictionary.com does not know such a word define:granuality on google is not found (and pages for granuality are mostly related to patches to the kernel) it has not been discussed as a term on LKML, AFAICS (=Can Search) To be consistent, I think granularity should be used everywhere. Signed-off-by: Kalin KOZHUHAROV <kalin@thinrope.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01BUG_ON() Conversion in kernel/printk.cEric Sesterhenn
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-04-01help text: SOFTWARE_SUSPEND doesn't need ACPIAdrian Bunk
The note that SOFTWARE_SUSPEND doesn't need APM is helpful, but nowadays the information that it doesn't need ACPI, too, is even more helpful. Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-31[PATCH] wrong error path in dup_fd() leading to oopses in RCUKirill Korotaev
Wrong error path in dup_fd() - it should return NULL on error, not an address of already freed memory :/ Triggered by OpenVZ stress test suite. What is interesting is that it was causing different oopses in RCU like below: Call Trace: [<c013492c>] rcu_do_batch+0x2c/0x80 [<c0134bdd>] rcu_process_callbacks+0x3d/0x70 [<c0126cf3>] tasklet_action+0x73/0xe0 [<c01269aa>] __do_softirq+0x10a/0x130 [<c01058ff>] do_softirq+0x4f/0x60 ======================= [<c0113817>] smp_apic_timer_interrupt+0x77/0x110 [<c0103b54>] apic_timer_interrupt+0x1c/0x24 Code: Bad EIP value. <0>Kernel panic - not syncing: Fatal exception in interrupt Signed-Off-By: Pavel Emelianov <xemul@sw.ru> Signed-Off-By: Dmitry Mishin <dim@openvz.org> Signed-Off-By: Kirill Korotaev <dev@openvz.org> Signed-Off-By: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] pidhash: Refactor the pid hash tableEric W. Biederman
Simplifies the code, reduces the need for 4 pid hash tables, and makes the code more capable. In the discussions I had with Oleg it was felt that to a large extent the cleanup itself justified the work. With struct pid being dynamically allocated meant we could create the hash table entry when the pid was allocated and free the hash table entry when the pid was freed. Instead of playing with the hash lists when ever a process would attach or detach to a process. For myself the fact that it gave what my previous task_ref patch gave for free with simpler code was a big win. The problem is that if you hold a reference to struct task_struct you lock in 10K of low memory. If you do that in a user controllable way like /proc does, with an unprivileged but hostile user space application with typical resource limits of 1000 fds and 100 processes I can trigger the OOM killer by consuming all of low memory with task structs, on a machine wight 1GB of low memory. If I instead hold a reference to struct pid which holds a pointer to my task_struct, I don't suffer from that problem because struct pid is 2 orders of magnitude smaller. In fact struct pid is small enough that most other kernel data structures dwarf it, so simply limiting the number of referring data structures is enough to prevent exhaustion of low memory. This splits the current struct pid into two structures, struct pid and struct pid_link, and reduces our number of hash tables from PIDTYPE_MAX to just one. struct pid_link is the per process linkage into the hash tables and lives in struct task_struct. struct pid is given an indepedent lifetime, and holds pointers to each of the pid types. The independent life of struct pid simplifies attach_pid, and detach_pid, because we are always manipulating the list of pids and not the hash table. In addition in giving struct pid an indpendent life it makes the concept much more powerful. Kernel data structures can now embed a struct pid * instead of a pid_t and not suffer from pid wrap around problems or from keeping unnecessarily large amounts of memory allocated. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] task: RCU protect task->usageEric W. Biederman
A big problem with rcu protected data structures that are also reference counted is that you must jump through several hoops to increase the reference count. I think someone finally implemented atomic_inc_not_zero(&count) to automate the common case. Unfortunately this means you must special case the rcu access case. When data structures are only visible via rcu in a manner that is not determined by the reference count on the object (i.e. tasks are visible until their zombies are reaped) there is a much simpler technique we can employ. Simply delaying the decrement of the reference count until the rcu interval is over. What that means is that the proc code that looks up a task and later wants to sleep can now do: rcu_read_lock(); task = find_task_by_pid(some_pid); if (task) { get_task_struct(task); } rcu_read_unlock(); The effect on the rest of the kernel is that put_task_struct becomes cheaper and immediate, and in the case where the task has been reaped it frees the task immediate instead of unnecessarily waiting an until the rcu interval is over. Cleanup of task_struct does not happen when its reference count drops to zero, instead cleanup happens when release_task is called. Tasks can only be looked up via rcu before release_task is called. All rcu protected members of task_struct are freed by release_task. Therefore we can move call_rcu from put_task_struct into release_task. And we can modify release_task to not immediately release the reference count but instead have it call put_task_struct from the function it gives to call_rcu. The end result: - get_task_struct is safe in an rcu context where we have just looked up the task. - put_task_struct() simplifies into its old pre rcu self. This reorganization also makes put_task_struct uncallable from modules as it is not exported but it does not appear to be called from any modules so this should not be an issue, and is trivially fixed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] resurrect __put_task_structAndrew Morton
This just got nuked in mainline. Bring it back because Eric's patches use it. Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] Make setsid() more robustEric W. Biederman
The core problem: setsid fails if it is called by init. The effect in 2.6.16 and the earlier kernels that have this problem is that if you do a "ps -j 1 or ps -ej 1" you will see that init and several of it's children have process group and session == 0. Instead of process group == session == 1. Despite init calling setsid. The reason it fails is that daemonize calls set_special_pids(1,1) on kernel threads that are launched before /sbin/init is called. The only remaining effect in that current->signal->leader == 0 for init instead of 1. And the setsid call fails. No one has noticed because /sbin/init does not check the return value of setsid. In 2.4 where we don't have the pidhash table, and daemonize doesn't exist setsid actually works for init. I care a lot about pid == 1 not being a special case that we leave broken, because of the container/jail work that I am doing. - Carefully allow init (pid == 1) to call setsid despite the kernel using its session. - Use find_task_by_pid instead of find_pid because find_pid taking a pidtype is going away. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] futex: check and validate timevalsThomas Gleixner
The futex timeval is not checked for correctness. The change does not break existing applications as the timeval is supplied by glibc (and glibc always passes a correct value), but the glibc-internal tests for this functionality fail. Signed-off-by: Thomas Gleixner <tglx@tglx.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: activate SCHED BATCH expiredCon Kolivas
To increase the strength of SCHED_BATCH as a scheduling hint we can activate batch tasks on the expired array since by definition they are latency insensitive tasks. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: remove on runqueue requeueingCon Kolivas
On runqueue time is used to elevate priority in schedule(). In the code it currently requeues tasks even if their priority is not elevated, which would end up placing them at the end of their runqueue array effectively delaying them instead of improving their priority. Bug spotted by Mike Galbraith <efault@gmx.de> This patch removes this requeueing. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: include noninteractive sleep in idle detectCon Kolivas
Tasks waiting in SLEEP_NONINTERACTIVE state can now get to best priority so they need to be included in the idle detection code. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: dont decrease idle sleep avgCon Kolivas
We watch for tasks that sleep extended periods and don't allow one single prolonged sleep period from elevating priority to maximum bonus to prevent cpu bound tasks from getting high priority with single long sleeps. There is a bug in the current code that also penalises tasks that already have high priority. Correct that bug. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: make task_noninteractive use sleep_typeCon Kolivas
Alterations to the pipe code in the kernel made it possible for relative starvation to occur with tasks that slept waiting on a pipe getting unfair priority bonuses even if they were otherwise fully cpu bound so the TASK_NONINTERACTIVE flag was introduced which prevented any change to sleep_avg while sleeping waiting on a pipe. This change also leads to the converse though, preventing any priority boost from occurring in truly interactive tasks that wait on pipes. Convert the TASK_NONINTERACTIVE flag to set sleep_type to SLEEP_NONINTERACTIVE which will allow a linear bonus to priority based on sleep time thus allowing interactive tasks to get high priority if they sleep enough. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: cleanup task_activated()Con Kolivas
The activated flag in task_struct is used to track different sleep types and its usage is somewhat obfuscated. Convert the variable to an enum with more descriptive names without altering the function. Signed-off-by: Con Kolivas <kernel@kolivas.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] sched: reduce overhead of calc_loadJack Steiner
Currently, count_active_tasks() calls both nr_running() & nr_interruptible(). Each of these functions does a "for_each_cpu" & reads values from the runqueue of each cpu. Although this is not a lot of instructions, each runqueue may be located on different node. Depending on the architecture, a unique TLB entry may be required to access each runqueue. Since there may be more runqueues than cpu TLB entries, a scan of all runqueues can trash the TLB. Each memory reference incurs a TLB miss & refill. In addition, the runqueue cacheline that contains nr_running & nr_uninterruptible may be evicted from the cache between the two passes. This causes unnecessary cache misses. Combining nr_running() & nr_interruptible() into a single function substantially reduces the TLB & cache misses on large systems. This should have no measureable effect on smaller systems. On a 128p IA64 system running a memory stress workload, the new function reduced the overhead of calc_load() from 605 usec/call to 324 usec/call. Signed-off-by: Jack Steiner <steiner@sgi.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] hrtimer: call get_softirq_time() only when necessary in ↵Dimitri Sivanich
run_hrtimer_queue() It seems that run_hrtimer_queue() is calling get_softirq_time() more often than it needs to. With this patch, it only calls get_softirq_time() if there's a pending timer. Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] hrtimer: use generic sleeper for nanosleepThomas Gleixner
Replace the nanosleep private sleeper functionality by the generic hrtimer sleeper. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] hrtimer: create generic sleeperThomas Gleixner
The removal of the data field in the hrtimer structure enforces the embedding of the timer into another data structure. nanosleep now uses a private implementation of the most common used timer callback function (simple task wakeup). In order to avoid the reimplentation of such functionality all over the place a generic hrtimer_sleeper functionality is created. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] modules: permit Dual-MIT/GPL licensesAndrew Morton
One of the LEDs driver files wants to use this. Probably drivers/mtd/maps/ipaq-flash.c wants to convert as well - right now it'll be tainting the kernel. Cc: David Woodhouse <dwmw2@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Bowler <jbowler@acm.org> Cc: "'Richard Purdie'" <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] cpuset: memory migration interaction fixPaul Jackson
Fix memory migration so that it works regardless of what cpuset the invoking task is in. If a task invoked a memory migration, by doing one of: 1) writing a different nodemask to a cpuset 'mems' file, or 2) writing a tasks pid to a different cpuset's 'tasks' file, where the cpuset had its 'memory_migrate' option turned on, then the allocation of the new pages for the migrated task(s) was constrained by the invoking tasks cpuset. If this task wasn't in a cpuset that allowed the requested memory nodes, the memory migration would happen to some other nodes that were in that invoking tasks cpuset. This was usually surprising and puzzling behaviour: Why didn't the pages move? Why did the pages move -there-? To fix this, temporarilly change the invoking tasks 'mems_allowed' task_struct field to the nodes the migrating tasks is moving to, so that new pages can be allocated there. Signed-off-by: Paul Jackson <pj@sgi.com> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] cpuset: unsafe mm reference fixPaul Jackson
Fix unsafe reference to a tasks mm struct, by moving the reference inside of a convenient nearby properly guarded code block. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] cpuset: task_lock comment fixPaul Jackson
Fix cpuset comment involving case of a tasks cpuset pointer being NULL. Thanks to "the_top_cpuset_hack", this code no longer sees NULL task->cpuset pointers. Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] Fix pacct bug in multithreading case.KaiGai Kohei
I noticed a bug on the process accounting facility. In multi-threading process, some data would be recorded incorrectly when the group_leader dies earlier than one or more threads. The attached patch fixes this problem. See below. 'bugacct' is a test program that create a worker thread after 4 seconds sleeping, then the group_leader dies soon. The worker thread consume CPU/Memory for 6 seconds, then exit. We can estimate 10 seconds as etime and 6 seconds as stime + utime. This is a sample program which the group_leader dies earlier than other threads. The results of same binary execution on different kernel are below. -- accounted records -------------------- | btime | utime | stime | etime | minflt | majflt | comm | original | 13:16:40 | 0.00 | 0.00 | 6.10 | 171 | 0 | bugacct | patched | 13:20:21 | 5.83 | 0.18 | 10.03 | 32776 | 0 | bugacct | (*) bugacct allocates 128MB memory, thus 128MB / 4KB = 32768 of minflt is appropriate. -- Test results in original kernel ------ $ date; time -p ./bugacct Tue Mar 28 13:16:36 JST 2006 <- But pacct said btime is 13:16:40 real 10.11 <- But pacct said etime is 6.10 user 5.96 <- But pacct said utime is 0.00 sys 0.14 <- But pacct said stime is 0.00 $ -- Test results in patched kernel ------- $ date; time -p ./bugacct Tue Mar 28 13:20:21 JST 2006 real 10.04 user 5.83 sys 0.19 $ In the original 2.6.16 kernel, pacct records btime, utime, stime, etime and minflt incorrectly. In my opinion, this problem is caused by an assumption that group_leader dies last. The following section calculates process running time for etime and btime. But it means running time of the thread that dies last, not process. The start_time of the first thread in the process (group_leader) should be reduced from uptime to calculate etime and btime correctly. ---- do_acct_process() in kernel/acct.c: /* calculate run_time in nsec*/ do_posix_clock_monotonic_gettime(&uptime); run_time = (u64)uptime.tv_sec*NSEC_PER_SEC + uptime.tv_nsec; run_time -= (u64)current->start_time.tv_sec*NSEC_PER_SEC + current->start_time.tv_nsec; ---- The following section calculates stime and utime of the process. But it might count the utime and stime of the group_leader duplicatly and ignore the utime and stime of the thread dies last, when one or more threads remain after group_leader dead. The ac_utime should be calculated as the sum of the signal->utime and utime of the thread dies last. The ac_stime should be done also. ---- do_acct_process() in kernel/acct.c: jiffies = cputime_to_jiffies(cputime_add(current->group_leader->utime, current->signal->utime)); ac.ac_utime = encode_comp_t(jiffies_to_AHZ(jiffies)); jiffies = cputime_to_jiffies(cputime_add(current->group_leader->stime, current->signal->stime)); ac.ac_stime = encode_comp_t(jiffies_to_AHZ(jiffies)); ---- The part of the minflt/majflt calculation has same problem. This patch solves those problems, I think. Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] Don't pass boot parameters to argv_init[]OGAWA Hirofumi
The boot cmdline is parsed in parse_early_param() and parse_args(,unknown_bootoption). And __setup() is used in obsolete_checksetup(). start_kernel() -> parse_args() -> unknown_bootoption() -> obsolete_checksetup() If __setup()'s callback (->setup_func()) returns 1 in obsolete_checksetup(), obsolete_checksetup() thinks a parameter was handled. If ->setup_func() returns 0, obsolete_checksetup() tries other ->setup_func(). If all ->setup_func() that matched a parameter returns 0, a parameter is seted to argv_init[]. Then, when runing /sbin/init or init=app, argv_init[] is passed to the app. If the app doesn't ignore those arguments, it will warning and exit. This patch fixes a wrong usage of it, however fixes obvious one only. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31[PATCH] __mod_timer: simplify ->base changingOleg Nesterov
Since base and new_base are of the same type now, we can save one 'if' branch and simplify the code a bit. 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>
2006-03-31[PATCH] kill __init_timer_base in favor of boot_tvec_basesOleg Nesterov
Commit a4a6198b80cf82eb8160603c98da218d1bd5e104: [PATCH] tvec_bases too large for per-cpu data introduced "struct tvec_t_base_s boot_tvec_bases" which is visible at compile time. This means we can kill __init_timer_base and move timer_base_s's content into tvec_t_base_s. 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>