- 20 5月, 2014 4 次提交
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由 Jens Axboe 提交于
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: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
We will use it for the pending list in blk-mq core as well. Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
Like commit f9c78b2b, move this block related file outside of fs/ and into the core block directory, block/. Signed-off-by: NJens Axboe <axboe@fb.com>
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- 19 5月, 2014 1 次提交
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由 Jens Axboe 提交于
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: NChristoph Hellwig <hch@infradead.org> Acked-by: NAl Viro <viro@ZenIV.linux.org.uk> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 14 5月, 2014 1 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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- 11 5月, 2014 4 次提交
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由 Ming Lei 提交于
Both nr_cache and nr_tags arn't needed for bitmap tag anymore. Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
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: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
The barrier isn't necessary because both atomic_dec_and_test() and wake_up() implicate one barrier. Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
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: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 10 5月, 2014 3 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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- 09 5月, 2014 3 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
This allows us to avoid a non-atomic memset over ->atomic_flags as well as killing lots of duplicate initializations. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
Signed-off-by: NJens Axboe <axboe@fb.com>
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- 08 5月, 2014 1 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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- 03 5月, 2014 3 次提交
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由 Fabian Frederick 提交于
Fix 4 coccinelle warnings. Cc: Jens Axboe <axboe@kernel.dk> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Fabian Frederick 提交于
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: NFabian Frederick <fabf@skynet.be> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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- 01 5月, 2014 3 次提交
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由 Masanari Iida 提交于
Fix format string mismatch in cfq_var_show() Signed-off-by: NMasanari Iida <standby24x7@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
It's never been of any use, lets get rid of it. Signed-off-by: NJens Axboe <axboe@fb.com>
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- 30 4月, 2014 1 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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- 25 4月, 2014 2 次提交
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
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: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 24 4月, 2014 3 次提交
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由 Jens Axboe 提交于
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: NJens Axboe <axboe@fb.com>
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由 Jens Axboe 提交于
This reverts commit 6a3c8a3a. 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.
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由 Ming Lei 提交于
set->tags should be freed in blk_mq_free_tag_set(). Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 22 4月, 2014 5 次提交
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由 Fabian Frederick 提交于
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: NFabian Frederick <fabf@skynet.be> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
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: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
Cc: Jörg-Volker Peetz <jvpeetz@web.de> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
type of set->tags is struct blk_mq_tags **. Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Ming Lei 提交于
Avoid memory leak in the failure path. Reviewed-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NMing Lei <tom.leiming@gmail.com> Signed-off-by: NJens Axboe <axboe@fb.com>
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- 17 4月, 2014 6 次提交
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由 Jens Axboe 提交于
Since we are now, by default, applying timer slack to expiry times, the logic for when to modify a timer in the block code is suboptimal. The block layer keeps a forward rolling timer per queue for all requests, and modifies this timer if a request has a shorter timeout than what the current expiry time is. However, this breaks down when our rounded timer values get applied slack. Then each new request ends up modifying the timer, since we're still a little in front of the timer + slack. Fix this by allowing a tolerance of HZ / 2, the timeout handling doesn't need to be very precise. This drastically cuts down the number of timer modifications we have to make. Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
This allows to mirror the blk-mq code flow for more a more readable I/O completion handler in SCSI. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
We will use this work_struct to requeue scsi commands from the completion handler as well, so give it a more generic name. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
This allows to requeue a request that has been accepted by ->queue_rq earlier. This is needed by the SCSI layer in various error conditions. The existing internal blk_mq_requeue_request is renamed to __blk_mq_requeue_request as it is a lower level building block for this funtionality. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Add a helper to unconditionally kick contexts of a queue. This will be needed by the SCSI layer to provide fair queueing between multiple devices on a single host. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NJens Axboe <axboe@fb.com>
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由 Christoph Hellwig 提交于
Add a blk-mq equivalent to blk_delay_queue so that the scsi layer can ask to be kicked again after a delay. Signed-off-by: NChristoph Hellwig <hch@lst.de> Modified by me to kill the unnecessary preempt disable/enable in the delayed workqueue handler. Signed-off-by: NJens Axboe <axboe@fb.com>
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