user/sven/linux.git/include/linux/wait.h, branch v4.4.194

sched/wait: Fix the signal handling fix

2015-12-13T22:30:59Z

Jan Stancek reported that I wrecked things for him by fixing things for Vladimir :/ His report was due to an UNINTERRUPTIBLE wait getting -EINTR, which should not be possible, however my previous patch made this possible by unconditionally checking signal_pending(). We cannot use current->state as was done previously, because the instruction after the store to that variable it can be changed. We must instead pass the initial state along and use that. Fixes: 68985633bccb ("sched/wait: Fix signal handling in bit wait helpers") Reported-by: Jan Stancek Reported-by: Chris Mason Tested-by: Jan Stancek Tested-by: Vladimir Murzin Tested-by: Chris Mason Reviewed-by: Paul Turner Cc: Ingo Molnar Cc: tglx@linutronix.de Cc: Oleg Nesterov Cc: hpa@zytor.com Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Linus Torvalds

userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key"

2015-09-22T22:09:53Z

This reverts commit 51360155eccb907ff8635bd10fc7de876408c2e0 and adapts fs/userfaultfd.c to use the old version of that function. It didn't look robust to call __wake_up_common with "nr == 1" when we absolutely require wakeall semantics, but we've full control of what we insert in the two waitqueue heads of the blocked userfaults. No exclusive waitqueue risks to be inserted into those two waitqueue heads so we can as well stick to "nr == 1" of the old code and we can rely purely on the fact no waitqueue inserted in one of the two waitqueue heads we must enforce as wakeall, has wait->flags WQ_FLAG_EXCLUSIVE set. Signed-off-by: Andrea Arcangeli Cc: Dr. David Alan Gilbert Cc: Michael Ellerman Cc: Shuah Khan Cc: Thierry Reding Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key

2015-09-04T23:54:41Z

userfaultfd needs to wake all waitqueues (pass 0 as nr parameter), instead of the current hardcoded 1 (that would wake just the first waitqueue in the head list). Signed-off-by: Andrea Arcangeli Acked-by: Pavel Emelyanov Cc: Sanidhya Kashyap Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" Cc: Andres Lagar-Cavilla Cc: Dave Hansen Cc: Paolo Bonzini Cc: Rik van Riel Cc: Mel Gorman Cc: Andy Lutomirski Cc: Hugh Dickins Cc: Peter Feiner Cc: "Dr. David Alan Gilbert" Cc: Johannes Weiner Cc: "Huangpeng (Peter)" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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