user/sven/linux.git/include/linux/wait.h, branch v4.2.4

Merge tag 'md/4.2' of git://neil.brown.name/md

2015-06-29T18:10:56Z

Pull md updates from Neil Brown: "A mixed bag - a few bug fixes - some performance improvement that decrease lock contention - some clean-up Nothing major" * tag 'md/4.2' of git://neil.brown.name/md: md: clear Blocked flag on failed devices when array is read-only. md: unlock mddev_lock on an error path. md: clear mddev->private when it has been freed. md: fix a build warning md/raid5: ignore released_stripes check md/raid5: per hash value and exclusive wait_for_stripe md/raid5: split wait_for_stripe and introduce wait_for_quiescent wait: introduce wait_event_exclusive_cmd md: convert to kstrto*() md/raid10: make sync_request_write() call bio_copy_data()

wait: introduce wait_event_exclusive_cmd

2015-06-17T00:00:14Z

It's just a variant of wait_event_cmd(), with exclusive flag being set. For cases like RAID5, which puts many processes to sleep until 1/4 resources are free, a wake_up wakes up all processes to run, but there is one process being able to get the resource as it's protected by a spin lock. That ends up introducing heavy lock contentions, and hurts performance badly. Here introduce wait_event_exclusive_cmd to relieve the lock contention naturally by letting wake_up just wake up one process. Cc: Ingo Molnar Cc: Peter Zijlstra v2: its assumed that wait*() and __wait*() have the same arguments - peterz Acked-by: Peter Zijlstra (Intel) Signed-off-by: Yuanhan Liu Signed-off-by: NeilBrown

sched/wait: Change wait_on_bit() to take an unsigned long , not a void *

2015-05-08T10:05:41Z

The implementations of wait_on_bit*() will only work with long-aligned memory on systems that don't support misaligned loads and stores. This patch changes the function prototypes to ensure that the compiler will enforce alignment. Running make defconfig make KFLAGS="-Werror" seems to indicate that, as of c56fb6564dcd ("Fix a misaligned load inside ptrace_attach()"), there are now no users of non-long-aligned calls to wait_on_bit*(). I additionally tried a few "make randconfig" attempts, none of which failed to compile for this reason. Signed-off-by: Palmer Dabbelt Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Chris Metcalf Cc: Andrew Morton Cc: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Thomas Gleixner Cc: bobby.prani@gmail.com Cc: oleg@redhat.com Cc: paulmck@linux.vnet.ibm.com Cc: richard@nod.at Cc: vdavydov@parallels.com Link: http://lkml.kernel.org/r/1430453997-32459-3-git-send-email-palmer@dabbelt.com Signed-off-by: Ingo Molnar

Merge branch 'for-3.20/drivers' of git://git.kernel.dk/linux-block

2015-02-12T22:30:53Z

Pull block driver changes from Jens Axboe: "This contains: - The 4k/partition fixes for brd from Boaz/Matthew. - A few xen front/back block fixes from David Vrabel and Roger Pau Monne. - Floppy changes from Takashi, cleaning the device file creation. - Switching libata to use the new blk-mq tagging policy, removing code (and a suboptimal implementation) from libata. This will throw you a merge conflict, since a bug in the original libata tagging code was fixed since this code was branched. Trivial. From Shaohua. - Conversion of loop to blk-mq, from Ming Lei. - Cleanup of the io_schedule() handling in bsg from Peter Zijlstra. He claims it improves on unreadable code, which will cost him a beer. - Maintainer update or NDB, now handled by Markus Pargmann. - NVMe: - Optimization from me that avoids a kmalloc/kfree per IO for smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU overhead. - Removal of (now) dead RCU code, a relic from before NVMe was converted to blk-mq" * 'for-3.20/drivers' of git://git.kernel.dk/linux-block: xen-blkback: default to X86_32 ABI on x86 xen-blkfront: fix accounting of reqs when migrating xen-blkback,xen-blkfront: add myself as maintainer block: Simplify bsg complete all floppy: Avoid manual call of device_create_file() NVMe: avoid kmalloc/kfree for smaller IO MAINTAINERS: Update NBD maintainer libata: make sata_sil24 use fifo tag allocator libata: move sas ata tag allocation to libata-scsi.c libata: use blk taging NVMe: within nvme_free_queues(), delete RCU sychro/deferred free null_blk: suppress invalid partition info brd: Request from fdisk 4k alignment brd: Fix all partitions BUGs axonram: Fix bug in direct_access loop: add blk-mq.h include block: loop: don't handle REQ_FUA explicitly block: loop: introduce lo_discard() and lo_req_flush() block: loop: say goodby to bio block: loop: improve performance via blk-mq

block: Simplify bsg complete all

2015-02-04T16:57:52Z

It took me a few tries to figure out what this code did; lets rewrite it into a more regular form. The thing that makes this one 'special' is the BSG_F_BLOCK flag, if that is not set we're not supposed/allowed to block and should spin wait for completion. The (new) io_wait_event() will never see a false condition in case of the spinning and we will therefore not block. Cc: Linus Torvalds Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Jens Axboe

sched/wait: Introduce wait_on_bit_timeout()

2015-02-04T06:52:32Z

Add a new wait_on_bit_timeout() helper, basically the same as wait_on_bit() except that it also takes a 'timeout' parameter. All the building blocks like bit_wait_timeout() and out_of_line_wait_on_bit_timeout() are already in place so the addition is rather simple. Signed-off-by: Johan Hedberg Signed-off-by: Peter Zijlstra (Intel) Cc: davem@davemloft.net Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1422616476-2917-2-git-send-email-johan.hedberg@gmail.com Signed-off-by: Ingo Molnar

sched/wait: Remove might_sleep() from wait_event_cmd()

2015-02-03T11:14:25Z

The patch e22b886a8a43 ("sched/wait: Add might_sleep() checks") introduced a bug in the raid5 subsystem. The function raid5_quiesce() (and resize_stripes()) uses the 'cmd' part to release and acquire a spinlock (so we call the sleep primitives in atomic context), and therefore we cannot do the might_sleep() check. Remove it. Fixes: e22b886a8a43 ("sched/wait: Add might_sleep() checks") Signed-off-by: Mikulas Patocka Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1502020935580.13510@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Ingo Molnar

sched/wait: Reimplement wait_event_freezable()

2014-11-04T06:17:45Z

Provide better implementations of wait_event_freezable() APIs. The problem is with freezer_do_not_count(), it hides the thread from the freezer, even though this thread might not actually freeze/sleep at all. Cc: oleg@redhat.com Cc: Rafael Wysocki Signed-off-by: Peter Zijlstra (Intel) Cc: Len Brown Cc: Linus Torvalds Cc: Pavel Machek Cc: Rafael J. Wysocki Cc: linux-pm@vger.kernel.org Link: http://lkml.kernel.org/n/tip-d86fz1jmso9wjxa8jfpinp8o@git.kernel.org Signed-off-by: Ingo Molnar

sched/wait: Add might_sleep() checks

2014-10-28T09:55:23Z

Add more might_sleep() checks, suppose someone put a wait_event() like thing in a wait loop.. Can't put might_sleep() in ___wait_event() because there's the locked primitives which call ___wait_event() with locks held. Signed-off-by: Peter Zijlstra (Intel) Cc: tglx@linutronix.de Cc: ilya.dryomov@inktank.com Cc: umgwanakikbuti@gmail.com Cc: Oleg Nesterov Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140924082242.119255706@infradead.org Signed-off-by: Ingo Molnar

sched/wait: Provide infrastructure to deal with nested blocking

2014-10-28T09:55:15Z

There are a few places that call blocking primitives from wait loops, provide infrastructure to support this without the typical task_struct::state collision. We record the wakeup in wait_queue_t::flags which leaves task_struct::state free to be used by others. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Oleg Nesterov Cc: tglx@linutronix.de Cc: ilya.dryomov@inktank.com Cc: umgwanakikbuti@gmail.com Cc: Linus Torvalds Link: http://lkml.kernel.org/r/20140924082242.051202318@infradead.org Signed-off-by: Ingo Molnar