linux/kernel/pid.c, branch v2.6.34

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2010-03-13T22:43:01Z

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: locking: Make sparse work with inline spinlocks and rwlocks x86/mce: Fix RCU lockdep splats rcu: Increase RCU CPU stall timeouts if PROVE_RCU ftrace: Replace read_barrier_depends() with rcu_dereference_raw() rcu: Suppress RCU lockdep warnings during early boot rcu, ftrace: Fix RCU lockdep splat in ftrace_perf_buf_prepare() rcu: Suppress __mpol_dup() false positive from RCU lockdep rcu: Make rcu_read_lock_sched_held() handle !PREEMPT rcu: Add control variables to lockdep_rcu_dereference() diagnostics rcu, cgroup: Relax the check in task_subsys_state() as early boot is now handled by lockdep-RCU rcu: Use wrapper function instead of exporting tasklist_lock sched, rcu: Fix rcu_dereference() for RCU-lockdep rcu: Make task_subsys_state() RCU-lockdep checks handle boot-time use rcu: Fix holdoff for accelerated GPs for last non-dynticked CPU x86/gart: Unexport gart_iommu_aperture Fix trivial conflicts in kernel/trace/ftrace.c

kernel/pid.c: update comment on find_task_by_pid_ns

2010-03-06T19:26:33Z

tasklist_lock does protect the task and its pid, it can't go away. The problem is that find_pid_ns() itself is unsafe without rcu lock, it can race with copy_process()->free_pid(any_pid). Protecting copy_process()->free_pid(any_pid) with tasklist_lock would make it possible to call find_task_by_pid_ns() under tasklist safely, but we don't do so because we are trying to get rid of the read_lock sites of tasklist_lock. Signed-off-by: Tetsuo Handa Cc: Oleg Nesterov Cc: "Paul E. McKenney" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rcu: Use wrapper function instead of exporting tasklist_lock

2010-03-04T10:46:14Z

Lockdep-RCU commit d11c563d exported tasklist_lock, which is not a good thing. This patch instead exports a function that uses lockdep to check whether tasklist_lock is held. Suggested-by: Christoph Hellwig Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: Christoph Hellwig LKML-Reference: <1267631219-8713-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar

sched: Use lockdep-based checking on rcu_dereference()

2010-02-25T09:34:26Z

Update the rcu_dereference() usages to take advantage of the new lockdep-based checking. Signed-off-by: Paul E. McKenney Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-6-git-send-email-paulmck@linux.vnet.ibm.com> [ -v2: fix allmodconfig missing symbol export build failure on x86 ] Signed-off-by: Ingo Molnar

pid: reduce code size by using a pointer to iterate over array

2009-12-16T15:20:12Z

It decreases code size by 16 bytes on my gcc 4.4.1 on Core 2: text data bss dec hex filename 4314 2216 8 6538 198a kernel/pid.o-BEFORE 4298 2216 8 6522 197a kernel/pid.o-AFTER Signed-off-by: André Goddard Rosa Cc: Pekka Enberg Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pid: tighten pidmap spinlock critical section by removing kfree()

2009-12-16T15:20:12Z

Avoid calling kfree() under pidmap spinlock, calling it afterwards. Normally kfree() is fast, but sometimes it can be slow, so avoid calling it under the spinlock if we can do it. Signed-off-by: André Goddard Rosa Cc: Pekka Enberg Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: also use alloc_large_system_hash() for the PID hash table

2009-09-22T14:17:38Z

This is being done by allowing boot time allocations to specify that they may want a sub-page sized amount of memory. Overall this seems more consistent with the other hash table allocations, and allows making two supposedly mm-only variables really mm-only (nr_{kernel,all}_pages). Signed-off-by: Jan Beulich Cc: Ingo Molnar Cc: "Eric W. Biederman" Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kmemleak: Remove alloc_bootmem annotations introduced in the past

2009-07-09T16:07:02Z

kmemleak_alloc() calls were added in some places where alloc_bootmem was called. Since now kmemleak tracks bootmem allocations, these explicit calls should be run. Signed-off-by: Catalin Marinas Cc: Ingo Molnar Acked-by: Pekka Enberg

kmemleak: Inform kmemleak about pid_hash

2009-06-29T16:14:14Z

Kmemleak does not track alloc_bootmem calls but the pid_hash allocated in pidhash_init() would need to be scanned as it contains pointers to struct pid objects. Signed-off-by: Catalin Marinas

pids: clean up find_task_by_pid variants

2009-06-18T20:03:55Z

find_task_by_pid_type_ns is only used to implement find_task_by_vpid and find_task_by_pid_ns, but both of them pass PIDTYPE_PID as first argument. So just fold find_task_by_pid_type_ns into find_task_by_pid_ns and use find_task_by_pid_ns to implement find_task_by_vpid. While we're at it also remove the exports for find_task_by_pid_ns and find_task_by_vpid - we don't have any modular callers left as the only modular caller of he old pre pid namespace find_task_by_pid (gfs2) was switched to pid_task which operates on a struct pid pointer instead of a pid_t. Given the confusion about pid_t values vs namespace that's generally the better option anyway and I think we're better of restricting modules to do it that way. Signed-off-by: Christoph Hellwig Cc: Pavel Emelyanov Cc: "Eric W. Biederman" Cc: Ingo Molnar Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds