kernel.git/kernel/exit.c, branch linux-2.6.14.y

Revert "remove false BUG_ON() from run_posix_cpu_timers()"

2005-10-27T16:07:33Z

This reverts commit 3de463c7d9d58f8cf3395268230cb20a4c15bffa. Roland has another patch that allows us to leave the BUG_ON() in place by just making sure that the condition it tests for really is always true. That goes in next. Signed-off-by: Linus Torvalds

[PATCH] posix-timers: remove false BUG_ON() from run_posix_cpu_timers()

2005-10-24T15:12:35Z

do_exit() clears ->it_##clock##_expires, but nothing prevents another cpu to attach the timer to exiting process after that. After exit_notify() does 'write_unlock_irq(&tasklist_lock)' and before do_exit() calls 'schedule() local timer interrupt can find tsk->exit_state != 0. If that state was EXIT_DEAD (or another cpu does sys_wait4) interrupted task has ->signal == NULL. At this moment exiting task has no pending cpu timers, they were cleaned up in __exit_signal()->posix_cpu_timers_exit{,_group}(), so we can just return from irq. Signed-off-by: Oleg Nesterov Signed-off-by: Linus Torvalds

[PATCH] Call exit_itimers from do_exit, not __exit_signal

2005-10-21T22:38:08Z

When I originally moved exit_itimers into __exit_signal, that was the only place where we could reliably know it was the last thread in the group dying, without races. Since then we've gotten the signal_struct.live counter, and do_exit can reliably do group-wide cleanup work. This patch moves the call to do_exit, where it's made without locks. This avoids the deadlock issues that the old __exit_signal code's comment talks about, and the one that Oleg found recently with process CPU timers. [ This replaces e03d13e985d48ac4885382c9e3b1510c78bd047f, which is why it was just reverted. ] Signed-off-by: Roland McGrath Signed-off-by: Linus Torvalds

Fix inequality comparison against "task->state"

2005-10-01T18:04:18Z

We should always use bitmask ops, rather than depend on some ordering of the different states. With the TASK_NONINTERACTIVE flag, the inequality doesn't really work. Oleg Nesterov argues (likely correctly) that this test is unnecessary in the first place. However, the minimal fix for now is to at least make it work in the presense of TASK_NONINTERACTIVE. Waiting for consensus from Roland & co on potential bigger cleanups. Signed-off-by: Linus Torvalds

[PATCH] files: fix preemption issues

2005-09-17T18:50:02Z

With the new fdtable locking rules, you have to protect fdtable with either ->file_lock or rcu_read_lock/unlock(). There are some places where we aren't doing either. This patch fixes those places. Signed-off-by: Dipankar Sarma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] files: files struct with RCU

2005-09-09T20:57:55Z

Patch to eliminate struct files_struct.file_lock spinlock on the reader side and use rcu refcounting rcuref_xxx api for the f_count refcounter. The updates to the fdtable are done by allocating a new fdtable structure and setting files->fdt to point to the new structure. The fdtable structure is protected by RCU thereby allowing lock-free lookup. For fd arrays/sets that are vmalloced, we use keventd to free them since RCU callbacks can't sleep. A global list of fdtable to be freed is not scalable, so we use a per-cpu list. If keventd is already handling the current cpu's work, we use a timer to defer queueing of that work. Since the last publication, this patch has been re-written to avoid using explicit memory barriers and use rcu_assign_pointer(), rcu_dereference() premitives instead. This required that the fd information is kept in a separate structure (fdtable) and updated atomically. Signed-off-by: Dipankar Sarma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] files: break up files struct

2005-09-09T20:57:55Z

In order for the RCU to work, the file table array, sets and their sizes must be updated atomically. Instead of ensuring this through too many memory barriers, we put the arrays and their sizes in a separate structure. This patch takes the first step of putting the file table elements in a separate structure fdtable that is embedded withing files_struct. It also changes all the users to refer to the file table using files_fdtable() macro. Subsequent applciation of RCU becomes easier after this. Signed-off-by: Dipankar Sarma Signed-Off-By: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] revert "timer exit cleanup"

2005-08-04T23:57:49Z

Revert this June 17 patch: it broke persistence of timers across execve(). Cc: Roland McGrath Cc: george anzinger Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Update cfq io scheduler to time sliced design

2005-06-27T21:33:29Z

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 Signed-off-by: Linus Torvalds

[PATCH] Optimize sys_times for a single thread process

2005-06-23T16:45:30Z

Avoid taking the tasklist_lock in sys_times if the process is single threaded. In a NUMA system taking the tasklist_lock may cause a bouncing cacheline if multiple independent processes continually call sys_times to measure their performance. Signed-off-by: Christoph Lameter Signed-off-by: Shai Fultheim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds