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2014-05-27blk-mq: fix leak of hctx->ctx_mapMing Lei1-0/+1
hctx->ctx_map should have been freed inside blk_mq_free_queue(). Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-27block/blk-lib.c: make __blkdev_issue_zeroout staticFabian Frederick1-2/+2
__blkdev_issue_zeroout is only used in blk-lib.c Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-27blk-mq: idle all hardware contexts before freeing a queueChristoph Hellwig1-0/+1
Without this we can leak the active_queues reference if a command is freed while it is considered active. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-24blk-mq: allow setting of per-request timeoutsJens Axboe1-2/+6
Currently blk-mq uses the queue timeout for all requests. But for some commands, drivers may want to set a specific timeout for special requests. Allow this to be passed in through request->timeout, and use it if set. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-23blk-mq: export blk_mq_tag_busy_iterSam Bradshaw2-1/+1
Export the blk-mq in-flight tag iterator for driver consumption. This is particularly useful in exception paths or SRSI where in-flight IOs need to be cancelled and/or reissued. The NVMe driver conversion will use this. Signed-off-by: Sam Bradshaw <sbradshaw@micron.com> Signed-off-by: Matias Bjørling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-22blk-mq: split make request handler for multi and single queueJens Axboe1-50/+157
We want slightly different behavior from them: - On single queue devices, we currently use the per-process plug for deferred IO and for merging. - On multi queue devices, we don't use the per-process plug, but we want to go straight to hardware for SYNC IO. Split blk_mq_make_request() into a blk_sq_make_request() for single queue devices, and retain blk_mq_make_request() for multi queue devices. Then we don't need multiple checks for q->nr_hw_queues in the request mapping. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-22blk-mq: save memory by freeing requests on unused hardware queuesJens Axboe1-52/+105
Depending on the topology of the machine and the number of queues exposed by a device, we can end up in a situation where some of the hardware queues are unused (as in, they don't map to any software queues). For this case, free up the memory used by the request map, as we will not use it. This can be a substantial amount of memory, depending on the number of queues vs CPUs and the queue depth of the device. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-21blk-mq: allow the hctx cpu hotplug notifier to return errorsJens Axboe3-9/+14
Prepare this for the next patch which adds more smarts in the plugging logic, so that we can save some memory. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-21blk-mq: Micro-optimize blk_queue_nomerges() checkRobert Elliott2-5/+6
In blk_mq_make_request(), do the blk_queue_nomerges() check outside the call to blk_attempt_plug_merge() to eliminate function call overhead when nomerges=2 (disabled) Signed-off-by: Robert Elliott <elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-21blk-mq: initialize q->nr_requests after calling blk_queue_make_request()Jens Axboe1-0/+5
blk_queue_make_requests() overwrites our set value for q->nr_requests, turning it into the default of 128. Set this appropriately after initializing queue values in blk_queue_make_request(). Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-20blk-mq: allow changing of queue depth through sysfsJens Axboe7-59/+133
For request_fn based devices, the block layer exports a 'nr_requests' file through sysfs to allow adjusting of queue depth on the fly. Currently this returns -EINVAL for blk-mq, since it's not wired up. Wire this up for blk-mq, so that it now also always dynamic adjustments of the allowed queue depth for any given block device managed by blk-mq. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-20block: move mm/bounce.c to block/Jens Axboe2-0/+288
Continue moving some of the block files that are scattered around. bounce.c contains only code for bouncing the contents of a bio. It's block proper code, not mm code. Suggested-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-19Merge branch 'for-3.16/blk-mq-tagging' into for-3.16/coreJens Axboe6-27/+224
Signed-off-by: Jens Axboe <axboe@fb.com> Conflicts: block/blk-mq-tag.c
2014-05-19blk-mq: switch ctx pending map to the sparser blk_align_bitmapJens Axboe1-28/+91
Each hardware queue has a bitmap of software queues with pending requests. When new IO is queued on a software queue, the bit is set, and when IO is pruned on a hardware queue run, the bit is cleared. This causes a lot of traffic. Switch this from the regular BITS_PER_LONG bitmap to a sparser layout, similarly to what was done for blk-mq tagging. 20% performance increase was observed for single threaded IO, and about 15% performanc increase on multiple threads driving the same device. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-19blk-mq: move the cache friendly bitmap type of out blk-mq-tagJens Axboe3-11/+17
We will use it for the pending list in blk-mq core as well. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-19block: move ioprio.c from fs/ to block/Jens Axboe2-1/+243
Like commit f9c78b2b, move this block related file outside of fs/ and into the core block directory, block/. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-19block: move bio.c and bio-integrity.c from fs/ to block/Jens Axboe3-1/+2697
They really belong in block/, especially now since it's not in drivers/block/ anymore. Additionally, the get_maintainer script gets it wrong when in fs/. Suggested-by: Christoph Hellwig <hch@infradead.org> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-16cgroup: remove css_parent()Tejun Heo1-1/+1
cgroup in general is moving towards using cgroup_subsys_state as the fundamental structural component and css_parent() was introduced to convert from using cgroup->parent to css->parent. It was quite some time ago and we're moving forward with making css more prominent. This patch drops the trivial wrapper css_parent() and let the users dereference css->parent. While at it, explicitly mark fields of css which are public and immutable. v2: New usage from device_cgroup.c converted. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: "David S. Miller" <davem@davemloft.net> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Johannes Weiner <hannes@cmpxchg.org>
2014-05-14blk-mq: improve support for shared tags mapsJens Axboe6-27/+224
This adds support for active queue tracking, meaning that the blk-mq tagging maintains a count of active users of a tag set. This allows us to maintain a notion of fairness between users, so that we can distribute the tag depth evenly without starving some users while allowing others to try unfair deep queues. If sharing of a tag set is detected, each hardware queue will track the depth of its own queue. And if this exceeds the total depth divided by the number of active queues, the user is actively throttled down. The active queue count is done lazily to avoid bouncing that data between submitter and completer. Each hardware queue gets marked active when it allocates its first tag, and gets marked inactive when 1) the last tag is cleared, and 2) the queue timeout grace period has passed. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-13cgroup: replace cftype->write_string() with cftype->write()Tejun Heo2-30/+30
Convert all cftype->write_string() users to the new cftype->write() which maps directly to kernfs write operation and has full access to kernfs and cgroup contexts. The conversions are mostly mechanical. * @css and @cft are accessed using of_css() and of_cft() accessors respectively instead of being specified as arguments. * Should return @nbytes on success instead of 0. * @buf is not trimmed automatically. Trim if necessary. Note that blkcg and netprio don't need this as the parsers already handle whitespaces. cftype->write_string() has no user left after the conversions and removed. While at it, remove unnecessary local variable @p in cgroup_subtree_control_write() and stale comment about CGROUP_LOCAL_BUFFER_SIZE in cgroup_freezer.c. This patch doesn't introduce any visible behavior changes. v2: netprio was missing from conversion. Converted. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Aristeu Rozanski <arozansk@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: "David S. Miller" <davem@davemloft.net>
2014-05-13cgroup: rename css_tryget*() to css_tryget_online*()Tejun Heo1-1/+1
Unlike the more usual refcnting, what css_tryget() provides is the distinction between online and offline csses instead of protection against upping a refcnt which already reached zero. cgroup is planning to provide actual tryget which fails if the refcnt already reached zero. Let's rename the existing trygets so that they clearly indicate that they're onliness. I thought about keeping the existing names as-are and introducing new names for the planned actual tryget; however, given that each controller participates in the synchronization of the online state, it seems worthwhile to make it explicit that these functions are about on/offline state. Rename css_tryget() to css_tryget_online() and css_tryget_from_dir() to css_tryget_online_from_dir(). This is pure rename. v2: cgroup_freezer grew new usages of css_tryget(). Update accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
2014-05-11Merge branch 'for-3.16/blk-mq-tagging' into for-3.16/coreJens Axboe2-25/+41
2014-05-11blk-mq: bitmap tag: cleanup blk_mq_init_tagsMing Lei1-4/+0
Both nr_cache and nr_tags arn't needed for bitmap tag anymore. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-11blk-mq: bitmap tag: select random tag betweet 0 and (depth - 1)Ming Lei1-4/+1
The selected tag should be selected at random between 0 and (depth - 1) with probability 1/depth, instead between 0 and (depth - 2) with probability 1/(depth - 1). Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-11blk-mq: bitmap tag: remove barrier in bt_clear_tag()Ming Lei1-1/+0
The barrier isn't necessary because both atomic_dec_and_test() and wake_up() implicate one barrier. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-11blk-mq: bitmap tag: use clear_bit_unlock in bt_clear_tag()Ming Lei1-1/+5
The unlock memory barrier need to order access to req in free path and clearing tag bit, otherwise either request free path may see a allocated request, or initialized request in allocate path might be modified by the ongoing free path. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-10block: only calculate part_in_flight() onceJens Axboe1-2/+5
We first check if we have inflight IO, then retrieve that same number again. Usually this isn't that costly since the chance of having the data dirtied in between is small, but there's no reason for calling part_in_flight() twice. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-10blk-mq: fix race in IO start accountingJens Axboe1-4/+2
Commit c6d600c6 opened up a small race where we could attempt to account IO completion on a request, racing with IO start accounting. Fix this up by ensuring that we've accounted for IO start before inserting the request. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-09blk-mq: use sparser tag layout for lower queue depthJens Axboe2-16/+36
For best performance, spreading tags over multiple cachelines makes the tagging more efficient on multicore systems. But since we have 8 * sizeof(unsigned long) tags per cacheline, we don't always get a nice spread. Attempt to spread the tags over at least 4 cachelines, using fewer number of bits per unsigned long if we have to. This improves tagging performance in setups with 32-128 tags. For higher depths, the spread is the same as before (BITS_PER_LONG tags per cacheline). Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-09blk-mq: implement new and more efficient tagging schemeJens Axboe4-97/+387
blk-mq currently uses percpu_ida for tag allocation. But that only works well if the ratio between tag space and number of CPUs is sufficiently high. For most devices and systems, that is not the case. The end result if that we either only utilize the tag space partially, or we end up attempting to fully exhaust it and run into lots of lock contention with stealing between CPUs. This is not optimal. This new tagging scheme is a hybrid bitmap allocator. It uses two tricks to both be SMP friendly and allow full exhaustion of the space: 1) We cache the last allocated (or freed) tag on a per blk-mq software context basis. This allows us to limit the space we have to search. The key element here is not caching it in the shared tag structure, otherwise we end up dirtying more shared cache lines on each allocate/free operation. 2) The tag space is split into cache line sized groups, and each context will start off randomly in that space. Even up to full utilization of the space, this divides the tag users efficiently into cache line groups, avoiding dirtying the same one both between allocators and between allocator and freeer. This scheme shows drastically better behaviour, both on small tag spaces but on large ones as well. It has been tested extensively to show better performance for all the cases blk-mq cares about. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-09blk-mq: initialize struct request fields individuallyChristoph Hellwig1-2/+45
This allows us to avoid a non-atomic memset over ->atomic_flags as well as killing lots of duplicate initializations. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-09blk-mq: update a hotplug comment for grammarJens Axboe1-4/+4
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-07blk-mq: add basic round-robin of what CPU to queue workqueue work onJens Axboe1-14/+31
Right now we just pick the first CPU in the mask, but that can easily overload that one. Add some basic batching and round-robin all the entries in the mask instead. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-05blkcg: use trylock on blkcg_pol_mutex in blkcg_reset_stats()Tejun Heo1-1/+14
During the recent conversion of cgroup to kernfs, cgroup_tree_mutex which nests above both the kernfs s_active protection and cgroup_mutex is added to synchronize cgroup file type operations as cgroup_mutex needed to be grabbed from some file operations and thus can't be put above s_active protection. While this arrangement mostly worked for cgroup, this triggered the following lockdep warning. ====================================================== [ INFO: possible circular locking dependency detected ] 3.15.0-rc3-next-20140430-sasha-00016-g4e281fa-dirty #429 Tainted: G W ------------------------------------------------------- trinity-c173/9024 is trying to acquire lock: (blkcg_pol_mutex){+.+.+.}, at: blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) but task is already holding lock: (s_active#89){++++.+}, at: kernfs_fop_write (fs/kernfs/file.c:283) which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (s_active#89){++++.+}: lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) __kernfs_remove (arch/x86/include/asm/atomic.h:27 fs/kernfs/dir.c:352 fs/kernfs/dir.c:1024) kernfs_remove_by_name_ns (fs/kernfs/dir.c:1219) cgroup_addrm_files (include/linux/kernfs.h:427 kernel/cgroup.c:1074 kernel/cgroup.c:2899) cgroup_clear_dir (kernel/cgroup.c:1092 (discriminator 2)) rebind_subsystems (kernel/cgroup.c:1144) cgroup_setup_root (kernel/cgroup.c:1568) cgroup_mount (kernel/cgroup.c:1716) mount_fs (fs/super.c:1094) vfs_kern_mount (fs/namespace.c:899) do_mount (fs/namespace.c:2238 fs/namespace.c:2561) SyS_mount (fs/namespace.c:2758 fs/namespace.c:2729) tracesys (arch/x86/kernel/entry_64.S:746) -> #1 (cgroup_tree_mutex){+.+.+.}: lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) cgroup_add_cftypes (include/linux/list.h:76 kernel/cgroup.c:3040) blkcg_policy_register (block/blk-cgroup.c:1106) throtl_init (block/blk-throttle.c:1694) do_one_initcall (init/main.c:789) kernel_init_freeable (init/main.c:854 init/main.c:863 init/main.c:882 init/main.c:1003) kernel_init (init/main.c:935) ret_from_fork (arch/x86/kernel/entry_64.S:552) -> #0 (blkcg_pol_mutex){+.+.+.}: __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) cgroup_file_write (kernel/cgroup.c:2714) kernfs_fop_write (fs/kernfs/file.c:295) vfs_write (fs/read_write.c:532) SyS_write (fs/read_write.c:584 fs/read_write.c:576) tracesys (arch/x86/kernel/entry_64.S:746) other info that might help us debug this: Chain exists of: blkcg_pol_mutex --> cgroup_tree_mutex --> s_active#89 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(s_active#89); lock(cgroup_tree_mutex); lock(s_active#89); lock(blkcg_pol_mutex); *** DEADLOCK *** 4 locks held by trinity-c173/9024: #0: (&f->f_pos_lock){+.+.+.}, at: __fdget_pos (fs/file.c:714) #1: (sb_writers#18){.+.+.+}, at: vfs_write (include/linux/fs.h:2255 fs/read_write.c:530) #2: (&of->mutex){+.+.+.}, at: kernfs_fop_write (fs/kernfs/file.c:283) #3: (s_active#89){++++.+}, at: kernfs_fop_write (fs/kernfs/file.c:283) stack backtrace: CPU: 3 PID: 9024 Comm: trinity-c173 Tainted: G W 3.15.0-rc3-next-20140430-sasha-00016-g4e281fa-dirty #429 ffffffff919687b0 ffff8805f6373bb8 ffffffff8e52cdbb 0000000000000002 ffffffff919d8400 ffff8805f6373c08 ffffffff8e51fb88 0000000000000004 ffff8805f6373c98 ffff8805f6373c08 ffff88061be70d98 ffff88061be70dd0 Call Trace: dump_stack (lib/dump_stack.c:52) print_circular_bug (kernel/locking/lockdep.c:1216) __lock_acquire (kernel/locking/lockdep.c:1840 kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131 kernel/locking/lockdep.c:3182) lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) mutex_lock_nested (kernel/locking/mutex.c:486 kernel/locking/mutex.c:587) blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455) cgroup_file_write (kernel/cgroup.c:2714) kernfs_fop_write (fs/kernfs/file.c:295) vfs_write (fs/read_write.c:532) SyS_write (fs/read_write.c:584 fs/read_write.c:576) This is a highly unlikely but valid circular dependency between "echo 1 > blkcg.reset_stats" and cfq module [un]loading. cgroup is going through further locking update which will remove this complication but for now let's use trylock on blkcg_pol_mutex and retry the file operation if the trylock fails. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Sasha Levin <sasha.levin@oracle.com> References: http://lkml.kernel.org/g/5363C04B.4010400@oracle.com
2014-05-05NVMe: Add tracepointsKeith Busch1-0/+1
Adding tracepoints for bio_complete and block_split into nvme to help with gathering IO info using blktrace and blkparse. Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-05-02block/blk-throttle.c: fix return of 0/1 with return type boolFabian Frederick1-4/+4
Fix 4 coccinelle warnings. Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-02block/blk-iopoll.c: use iop instead of iopollFabian Frederick1-2/+2
All blk_iopoll functions use iop for parent iopoll structure except blk_iopoll_complete.This also fixes one kernel-doc warning. Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-02blk-mq: remove extra requeue traceJens Axboe1-4/+0
We already issue a blktrace requeue event in __blk_mq_requeue_request(), don't do it from the original caller as well. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-01block: Fix format string mismatch in cfq-iosched.cMasanari Iida1-1/+1
Fix format string mismatch in cfq_var_show() Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-30blk-mq: refactor request insertion/mergingJens Axboe1-7/+15
Refactor the logic around adding a new bio to a software queue, so we nest the ctx->lock where we really need it (merge and insertion) and don't hold it when we don't (init and IO start accounting). Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-30blk-mq remove debug BUG_ON() when draining software queuesJens Axboe1-1/+0
It's never been of any use, lets get rid of it. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-30blk-mq: fix waiting for reserved tagsJens Axboe3-4/+4
blk_mq_wait_for_tags() is only able to wait for "normal" tags, not reserved tags. Pass in which one we should attempt to get a tag for, so that waiting for reserved tags will work. Reserved tags are used for internal commands, which are usually serialized. Hence no waiting generally takes place, but we should ensure that it actually works if users need that functionality. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-25block: fold __blk_add_timer into blk_add_timerChristoph Hellwig1-23/+11
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-25blk-mq: respect rq_affinityChristoph Hellwig3-45/+6
The blk-mq code is using it's own version of the I/O completion affinity tunables, which causes a few issues: - the rq_affinity sysfs file doesn't work for blk-mq devices, even if it still is present, thus breaking existing tuning setups. - the rq_affinity = 1 mode, which is the defauly for legacy request based drivers isn't implemented at all. - blk-mq drivers don't implement any completion affinity with the default flag settings. This patches removes the blk-mq ipi_redirect flag and sysfs file, as well as the internal BLK_MQ_F_SHOULD_IPI flag and replaces it with code that respects the queue-wide rq_affinity flags and also implements the rq_affinity = 1 mode. This means I/O completion affinity can now only be tuned block-queue wide instead of per context, which seems more sensible to me anyway. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-24blk-mq: fix race with timeouts and requeue eventsJens Axboe4-18/+42
If a requeue event races with a timeout, we can get into the situation where we attempt to complete a request from the timeout handler when it's not start anymore. This causes a crash. So have the timeout handler check that REQ_ATOM_STARTED is still set on the request - if not, we ignore the event. If this happens, the request has now been marked as complete. As a consequence, we need to ensure to clear REQ_ATOM_COMPLETE in blk_mq_start_request(), as to maintain proper request state. Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-24Revert "blk-mq: initialize req->q in allocation"Jens Axboe1-3/+1
This reverts commit 6a3c8a3ac0e68dcfc2a01f4aa1ca0edd1a1701eb. We need selective clearing of the request to make the init-at-free time completely safe. Otherwise we end up stomping on rq->atomic_flags, which we don't want to do.
2014-04-23blk-mq: fix leak of set->tagsMing Lei1-0/+1
set->tags should be freed in blk_mq_free_tag_set(). Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-22block/blk-throttle.c: add static to blk_throtl_dispatch_work_fnFabian Frederick1-1/+1
blk_throtl_dispatch_work_fn is only used in blk-throttle.c Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-21blk-mq: initialize req->q in allocationMing Lei1-1/+3
The patch basically reverts the patch of(blk-mq: initialize request on allocation) in Jens's tree(already in -next), and only initialize req->q in allocation for two reasons: - presumed cache hotness on completion - blk_rq_tagged(rq) depends on reset of req->mq_ctx Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-21blk-mq: user (1 << order) to implement order_to_size()Ming Lei1-6/+1
Cc: Jörg-Volker Peetz <jvpeetz@web.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>