pm24.git/kernel/fork.c, branch v3.13-rc2

mm: implement split page table lock for PMD level

2013-11-15T00:32:15Z

The basic idea is the same as with PTE level: the lock is embedded into struct page of table's page. We can't use mm->pmd_huge_pte to store pgtables for THP, since we don't take mm->page_table_lock anymore. Let's reuse page->lru of table's page for that. pgtable_pmd_page_ctor() returns true, if initialization is successful and false otherwise. Current implementation never fails, but assumption that constructor can fail will help to port it to -rt where spinlock_t is rather huge and cannot be embedded into struct page -- dynamic allocation is required. Signed-off-by: Naoya Horiguchi Signed-off-by: Kirill A. Shutemov Tested-by: Alex Thorlton Cc: Ingo Molnar Cc: "Eric W . Biederman" Cc: "Paul E . McKenney" Cc: Al Viro Cc: Andi Kleen Cc: Andrea Arcangeli Cc: Dave Hansen Cc: Dave Jones Cc: David Howells Cc: Frederic Weisbecker Cc: Johannes Weiner Cc: Kees Cook Cc: Mel Gorman Cc: Michael Kerrisk Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Robin Holt Cc: Sedat Dilek Cc: Srikar Dronamraju Cc: Thomas Gleixner Cc: Hugh Dickins Reviewed-by: Steven Rostedt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: convert mm->nr_ptes to atomic_long_t

2013-11-15T00:32:14Z

With split page table lock for PMD level we can't hold mm->page_table_lock while updating nr_ptes. Let's convert it to atomic_long_t to avoid races. Signed-off-by: Kirill A. Shutemov Tested-by: Alex Thorlton Cc: Ingo Molnar Cc: Naoya Horiguchi Cc: "Eric W . Biederman" Cc: "Paul E . McKenney" Cc: Al Viro Cc: Andi Kleen Cc: Andrea Arcangeli Cc: Dave Hansen Cc: Dave Jones Cc: David Howells Cc: Frederic Weisbecker Cc: Johannes Weiner Cc: Kees Cook Cc: Mel Gorman Cc: Michael Kerrisk Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Rik van Riel Cc: Robin Holt Cc: Sedat Dilek Cc: Srikar Dronamraju Cc: Thomas Gleixner Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2013-11-12T01:20:12Z

Pull scheduler changes from Ingo Molnar: "The main changes in this cycle are: - (much) improved CONFIG_NUMA_BALANCING support from Mel Gorman, Rik van Riel, Peter Zijlstra et al. Yay! - optimize preemption counter handling: merge the NEED_RESCHED flag into the preempt_count variable, by Peter Zijlstra. - wait.h fixes and code reorganization from Peter Zijlstra - cfs_bandwidth fixes from Ben Segall - SMP load-balancer cleanups from Peter Zijstra - idle balancer improvements from Jason Low - other fixes and cleanups" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (129 commits) ftrace, sched: Add TRACE_FLAG_PREEMPT_RESCHED stop_machine: Fix race between stop_two_cpus() and stop_cpus() sched: Remove unnecessary iteration over sched domains to update nr_busy_cpus sched: Fix asymmetric scheduling for POWER7 sched: Move completion code from core.c to completion.c sched: Move wait code from core.c to wait.c sched: Move wait.c into kernel/sched/ sched/wait: Fix __wait_event_interruptible_lock_irq_timeout() sched: Avoid throttle_cfs_rq() racing with period_timer stopping sched: Guarantee new group-entities always have weight sched: Fix hrtimer_cancel()/rq->lock deadlock sched: Fix cfs_bandwidth misuse of hrtimer_expires_remaining sched: Fix race on toggling cfs_bandwidth_used sched: Remove extra put_online_cpus() inside sched_setaffinity() sched/rt: Fix task_tick_rt() comment sched/wait: Fix build breakage sched/wait: Introduce prepare_to_wait_event() sched/wait: Add ___wait_cond_timeout() to wait_event*_timeout() too sched: Remove get_online_cpus() usage sched: Fix race in migrate_swap_stop() ...

uprobes: Teach uprobe_copy_process() to handle CLONE_VFORK

2013-10-29T17:02:55Z

uprobe_copy_process() does nothing if the child shares ->mm with the forking process, but there is a special case: CLONE_VFORK. In this case it would be more correct to do dup_utask() but avoid dup_xol(). This is not that important, the child should not unwind its stack too much, this can corrupt the parent's stack, but at least we need this to allow to ret-probe __vfork() itself. Note: in theory, it would be better to check task_pt_regs(p)->sp instead of CLONE_VFORK, we need to dup_utask() if and only if the child can return from the function called by the parent. But this needs the arch-dependant helper, and I think that nobody actually does clone(same_stack, CLONE_VM). Reported-by: Martin Cermak Reported-by: David Smith Signed-off-by: Oleg Nesterov

uprobes: Change the callsite of uprobe_copy_process()

2013-10-29T17:02:48Z

Preparation for the next patches. Move the callsite of uprobe_copy_process() in copy_process() down to the succesfull return. We do not care if copy_process() fails, uprobe_free_utask() won't be called in this case so the wrong ->utask != NULL doesn't matter. OTOH, with this change we know that copy_process() can't fail when uprobe_copy_process() is called, the new task should either return to user-mode or call do_exit(). This way uprobe_copy_process() can: 1. setup p->utask != NULL if necessary 2. setup uprobes_state.xol_area 3. use task_work_add(p) Also, move the definition of uprobe_copy_process() down so that it can see get_utask(). Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju

sched/numa: Stay on the same node if CLONE_VM

2013-10-09T12:47:57Z

A newly spawned thread inside a process should stay on the same NUMA node as its parent. This prevents processes from being "torn" across multiple NUMA nodes every time they spawn a new thread. Signed-off-by: Rik van Riel Signed-off-by: Mel Gorman Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-49-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar

Revert "mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node"

2013-10-09T10:40:17Z

PTE scanning and NUMA hinting fault handling is expensive so commit 5bca2303 ("mm: sched: numa: Delay PTE scanning until a task is scheduled on a new node") deferred the PTE scan until a task had been scheduled on another node. The problem is that in the purely shared memory case that this may never happen and no NUMA hinting fault information will be captured. We are not ruling out the possibility that something better can be done here but for now, this patch needs to be reverted and depend entirely on the scan_delay to avoid punishing short-lived processes. Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Cc: Andrea Arcangeli Cc: Johannes Weiner Cc: Srikar Dronamraju Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1381141781-10992-16-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar

Merge git://git.kvack.org/~bcrl/aio-next

2013-09-13T17:55:58Z

Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...

mm: mempolicy: turn vma_set_policy() into vma_dup_policy()

2013-09-11T22:57:00Z

Simple cleanup. Every user of vma_set_policy() does the same work, this looks a bit annoying imho. And the new trivial helper which does mpol_dup() + vma_set_policy() to simplify the callers. Signed-off-by: Oleg Nesterov Cc: KOSAKI Motohiro Cc: Mel Gorman Cc: Rik van Riel Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

fork: unify and tighten up CLONE_NEWUSER/CLONE_NEWPID checks

2013-09-11T22:56:20Z

do_fork() denies CLONE_THREAD | CLONE_PARENT if NEWUSER | NEWPID. Then later copy_process() denies CLONE_SIGHAND if the new process will be in a different pid namespace (task_active_pid_ns() doesn't match current->nsproxy->pid_ns). This looks confusing and inconsistent. CLONE_NEWPID is very similar to the case when ->pid_ns was already unshared, we want the same restrictions so copy_process() should also nack CLONE_PARENT. And it would be better to deny CLONE_NEWUSER && CLONE_SIGHAND as well just for consistency. Kill the "CLONE_NEWUSER | CLONE_NEWPID" check in do_fork() and change copy_process() to do the same check along with ->pid_ns check we already have. Signed-off-by: Oleg Nesterov Acked-by: Andy Lutomirski Cc: "Eric W. Biederman" Cc: Colin Walters Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds