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2017-11-15block/blk-mq.c: use kmalloc_array_node()Johannes Thumshirn
Now that we have a NUMA-aware version of kmalloc_array() we can use it instead of kmalloc_node() without an overflow check in the size calculation. Link: http://lkml.kernel.org/r/20170927082038.3782-3-jthumshirn@suse.de Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Doug Ledford <dledford@redhat.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Cc: Mike Marciniszyn <infinipath@intel.com> Cc: Santosh Shilimkar <santosh.shilimkar@oracle.com> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-10blk-mq: fixup some comment typos and lengthsJens Axboe
Various typos and/or spelling errors in comments. Fixes a few > 80 char lines as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10blk-mq: improve tag waiting setup for non-shared tagsJens Axboe
If we run out of driver tags, we currently treat shared and non-shared tags the same - both cases hook into the tag waitqueue. This is a bit more costly than it needs to be on unshared tags, since we have to both grab the hctx lock, and the waitqueue lock (and disable interrupts). For the non-shared case, we can simply mark the queue as needing a restart. Split blk_mq_dispatch_wait_add() to account for both cases, and rename it to blk_mq_mark_tag_wait() to better reflect what it does now. Without this patch, shared and non-shared performance is about the same with 4 fio thread hammering on a single null_blk device (~410K, at 75% sys). With the patch, the shared case is the same, but the non-shared tags case runs at 431K at 71% sys. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10blk-mq: only run the hardware queue if IO is pendingJens Axboe
Currently we are inconsistent in when we decide to run the queue. Using blk_mq_run_hw_queues() we check if the hctx has pending IO before running it, but we don't do that from the individual queue run function, blk_mq_run_hw_queue(). This results in a lot of extra and pointless queue runs, potentially, on flush requests and (much worse) on tag starvation situations. This is observable just looking at top output, with lots of kworkers active. For the !async runs, it just adds to the CPU overhead of blk-mq. Move the has-pending check into the run function instead of having callers do it. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block, nvme: Introduce blk_mq_req_flags_tBart Van Assche
Several block layer and NVMe core functions accept a combination of BLK_MQ_REQ_* flags through the 'flags' argument but there is no verification at compile time whether the right type of block layer flags is passed. Make it possible for sparse to verify this. This patch does not change any functionality. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: linux-nvme@lists.infradead.org Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block, scsi: Make SCSI quiesce and resume work reliablyBart Van Assche
The contexts from which a SCSI device can be quiesced or resumed are: * Writing into /sys/class/scsi_device/*/device/state. * SCSI parallel (SPI) domain validation. * The SCSI device power management methods. See also scsi_bus_pm_ops. It is essential during suspend and resume that neither the filesystem state nor the filesystem metadata in RAM changes. This is why while the hibernation image is being written or restored that SCSI devices are quiesced. The SCSI core quiesces devices through scsi_device_quiesce() and scsi_device_resume(). In the SDEV_QUIESCE state execution of non-preempt requests is deferred. This is realized by returning BLKPREP_DEFER from inside scsi_prep_state_check() for quiesced SCSI devices. Avoid that a full queue prevents power management requests to be submitted by deferring allocation of non-preempt requests for devices in the quiesced state. This patch has been tested by running the following commands and by verifying that after each resume the fio job was still running: for ((i=0; i<10; i++)); do ( cd /sys/block/md0/md && while true; do [ "$(<sync_action)" = "idle" ] && echo check > sync_action sleep 1 done ) & pids=($!) for d in /sys/class/block/sd*[a-z]; do bdev=${d#/sys/class/block/} hcil=$(readlink "$d/device") hcil=${hcil#../../../} echo 4 > "$d/queue/nr_requests" echo 1 > "/sys/class/scsi_device/$hcil/device/queue_depth" fio --name="$bdev" --filename="/dev/$bdev" --buffered=0 --bs=512 \ --rw=randread --ioengine=libaio --numjobs=4 --iodepth=16 \ --iodepth_batch=1 --thread --loops=$((2**31)) & pids+=($!) done sleep 1 echo "$(date) Hibernating ..." >>hibernate-test-log.txt systemctl hibernate sleep 10 kill "${pids[@]}" echo idle > /sys/block/md0/md/sync_action wait echo "$(date) Done." >>hibernate-test-log.txt done Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name> References: "I/O hangs after resuming from suspend-to-ram" (https://marc.info/?l=linux-block&m=150340235201348). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Martin Steigerwald <martin@lichtvoll.de> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: Introduce BLK_MQ_REQ_PREEMPTBart Van Assche
Set RQF_PREEMPT if BLK_MQ_REQ_PREEMPT is passed to blk_get_request_flags(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Martin Steigerwald <martin@lichtvoll.de> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Christoph Hellwig <hch@lst.de> Cc: Ming Lei <ming.lei@redhat.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: Make q_usage_counter also track legacy requestsMing Lei
This patch makes it possible to pause request allocation for the legacy block layer by calling blk_mq_freeze_queue() and blk_mq_unfreeze_queue(). Signed-off-by: Ming Lei <ming.lei@redhat.com> [ bvanassche: Combined two patches into one, edited a comment and made sure REQ_NOWAIT is handled properly in blk_old_get_request() ] Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Martin Steigerwald <martin@lichtvoll.de> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10blk-mq: fix issue with shared tag queue re-runningJens Axboe
This patch attempts to make the case of hctx re-running on driver tag failure more robust. Without this patch, it's pretty easy to trigger a stall condition with shared tags. An example is using null_blk like this: modprobe null_blk queue_mode=2 nr_devices=4 shared_tags=1 submit_queues=1 hw_queue_depth=1 which sets up 4 devices, sharing the same tag set with a depth of 1. Running a fio job ala: [global] bs=4k rw=randread norandommap direct=1 ioengine=libaio iodepth=4 [nullb0] filename=/dev/nullb0 [nullb1] filename=/dev/nullb1 [nullb2] filename=/dev/nullb2 [nullb3] filename=/dev/nullb3 will inevitably end with one or more threads being stuck waiting for a scheduler tag. That IO is then stuck forever, until someone else triggers a run of the queue. Ensure that we always re-run the hardware queue, if the driver tag we were waiting for got freed before we added our leftover request entries back on the dispatch list. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10blk-mq: put driver tag if dispatch budget can't be gotMing Lei
We have to put the driver tag if dispatch budget can't be got, otherwise it might cause IO deadlock, especially in case that size of tags is very small. Fixes: de1482974080(blk-mq: introduce .get_budget and .put_budget in blk_mq_ops) Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-04blk-mq: don't allocate driver tag upfront for flush rqMing Lei
The idea behind it is simple: 1) for none scheduler, driver tag has to be borrowed for flush rq, otherwise we may run out of tag, and that causes an IO hang. And get/put driver tag is actually noop for none, so reordering tags isn't necessary at all. 2) for a real I/O scheduler, we need not allocate a driver tag upfront for flush rq. It works just fine to follow the same approach as normal requests: allocate driver tag for each rq just before calling ->queue_rq(). One driver visible change is that the driver tag isn't shared in the flush request sequence. That won't be a problem, since we always do that in legacy path. Then flush rq need not be treated specially wrt. get/put driver tag. This cleans up the code - for instance, reorder_tags_to_front() can be removed, and we needn't worry about request ordering in dispatch list for avoiding I/O deadlock. Also we have to put the driver tag before requeueing. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-04blk-mq: move blk_mq_put_driver_tag*() into blk-mq.hMing Lei
We need this helper to put the driver tag for flush rq, since we will not share tag in the flush request sequence in the following patch in case that I/O scheduler is applied. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-04block: pass 'run_queue' to blk_mq_request_bypass_insertMing Lei
Block flush need this function without running the queue, so add a parameter controlling whether we run it or not. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-04blk-mq: put the driver tag of nxt rq before first one is requeuedJianchao Wang
When freeing the driver tag of the next rq with an I/O scheduler configured, we get the first entry of the list. However, this can race with requeue of a request, and we end up getting the wrong request from the head of the list. Free the driver tag of next rq before the failed one is requeued in the failure branch of queue_rq callback. Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-04blk-mq: don't handle failure in .get_budgetMing Lei
It is enough to just check if we can get the budget via .get_budget(). And we don't need to deal with device state change in .get_budget(). For SCSI, one issue to be fixed is that we have to call scsi_mq_uninit_cmd() to free allocated ressources if SCSI device fails to handle the request. And it isn't enough to simply call blk_mq_end_request() to do that if this request is marked as RQF_DONTPREP. Fixes: 0df21c86bdbf(scsi: implement .get_budget and .put_budget for blk-mq) Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03blk-mq: Make blk_mq_get_request() error path less confusingBart Van Assche
blk_mq_get_tag() can modify data->ctx. This means that in the error path of blk_mq_get_request() data->ctx should be passed to blk_mq_put_ctx() instead of local_ctx. Note: since blk_mq_put_ctx() ignores its argument, this patch does not change any functionality. References: commit 1ad43c0078b7 ("blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed") Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03blk-mq: fix nr_requests wrong value when modify it from sysfsweiping zhang
if blk-mq use "none" io scheduler, nr_request get a wrong value when input a number > tag_set->queue_depth. blk_mq_tag_update_depth will get the smaller one min(nr, set->queue_depth), and then q->nr_request get a wrong value. Reproduce: echo none > /sys/block/nvme0n1/queue/scheduler echo 1000000 > /sys/block/nvme0n1/queue/nr_requests cat /sys/block/nvme0n1/queue/nr_requests 1000000 Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-03block: add a poll_fn callback to struct request_queueChristoph Hellwig
That we we can also poll non blk-mq queues. Mostly needed for the NVMe multipath code, but could also be useful elsewhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-01blk-mq: don't restart queue when .get_budget returns BLK_STS_RESOURCEMing Lei
SCSI restarts its queue in scsi_end_request() automatically, so we don't need to handle this case in blk-mq. Especailly any request won't be dequeued in this case, we needn't to worry about IO hang caused by restart vs. dispatch. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-01blk-mq-sched: improve dispatching from sw queueMing Lei
SCSI devices use host-wide tagset, and the shared driver tag space is often quite big. However, there is also a queue depth for each lun( .cmd_per_lun), which is often small, for example, on both lpfc and qla2xxx, .cmd_per_lun is just 3. So lots of requests may stay in sw queue, and we always flush all belonging to same hw queue and dispatch them all to driver. Unfortunately it is easy to cause queue busy because of the small .cmd_per_lun. Once these requests are flushed out, they have to stay in hctx->dispatch, and no bio merge can happen on these requests, and sequential IO performance is harmed. This patch introduces blk_mq_dequeue_from_ctx for dequeuing a request from a sw queue, so that we can dispatch them in scheduler's way. We can then avoid dequeueing too many requests from sw queue, since we don't flush ->dispatch completely. This patch improves dispatching from sw queue by using the .get_budget and .put_budget callbacks. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-01blk-mq: introduce .get_budget and .put_budget in blk_mq_opsMing Lei
For SCSI devices, there is often a per-request-queue depth, which needs to be respected before queuing one request. Currently blk-mq always dequeues the request first, then calls .queue_rq() to dispatch the request to lld. One obvious issue with this approach is that I/O merging may not be successful, because when the per-request-queue depth can't be respected, .queue_rq() has to return BLK_STS_RESOURCE, and then this request has to stay in hctx->dispatch list. This means it never gets a chance to be merged with other IO. This patch introduces .get_budget and .put_budget callback in blk_mq_ops, then we can try to get reserved budget first before dequeuing request. If the budget for queueing I/O can't be satisfied, we don't need to dequeue request at all. Hence the request can be left in the IO scheduler queue, for more merging opportunities. Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-10block: set request_list for requestShaohua Li
Legacy queue sets request's request_list, mq doesn't. This makes mq does the same thing, so we can find cgroup of a request. Note, we really only use blkg field of request_list, it's pointless to allocate mempool for request_list in mq case. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-04blk-mq: document the need to have STARTED and COMPLETED share a byteJens Axboe
For memory ordering guarantees on stores, we need to ensure that these two bits share the same byte of storage in the unsigned long. Add a comment as to why, and a BUILD_BUG_ON() to ensure that we don't violate this requirement. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-04blk-mq: attempt to fix atomic flag memory orderingPeter Zijlstra
Attempt to untangle the ordering in blk-mq. The patch introducing the single smp_mb__before_atomic() is obviously broken in that it doesn't clearly specify a pairing barrier and an obtained guarantee. The comment is further misleading in that it hints that the deadline store and the COMPLETE store also need to be ordered, but AFAICT there is no such dependency. However what does appear to be important is the clear happening _after_ the store, and that worked by pure accident. This clarifies blk_mq_start_request() -- we should not get there with STARTING set -- this simplifies the code and makes the barrier usage sane (the old code could be read to allow not having _any_ atomic after the barrier, in which case the barrier hasn't got anything to order). We then also introduce the missing pairing barrier for it. Also down-grade the barrier to smp_wmb(), this is cheaper for PowerPC/ARM and doesn't cost anything extra on x86. And it documents the STARTING vs COMPLETE ordering. Although I've not been entirely successful in reverse engineering the blk-mq state machine so there might still be more funnies around timeout vs requeue. If I got anything wrong, feel free to educate me by adding comments to clarify things ;-) Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Fixes: 538b75341835 ("blk-mq: request deadline must be visible before marking rq as started") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-03blk-mq: wire up completion notifier for laptop modeJens Axboe
For some reason, the laptop mode IO completion notified was never wired up for blk-mq. Ensure that we trigger the callback appropriately, to arm the laptop mode flush timer. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-30blk-mq: remove unused function hctx_allow_mergesweiping zhang
since 9bddeb2a5b981 "blk-mq: make per-sw-queue bio merge as default .bio_merge" there is no caller for this function. Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-11block: directly insert blk-mq request from blk_insert_cloned_request()Jens Axboe
A NULL pointer crash was reported for the case of having the BFQ IO scheduler attached to the underlying blk-mq paths of a DM multipath device. The crash occured in blk_mq_sched_insert_request()'s call to e->type->ops.mq.insert_requests(). Paolo Valente correctly summarized why the crash occured with: "the call chain (dm_mq_queue_rq -> map_request -> setup_clone -> blk_rq_prep_clone) creates a cloned request without invoking e->type->ops.mq.prepare_request for the target elevator e. The cloned request is therefore not initialized for the scheduler, but it is however inserted into the scheduler by blk_mq_sched_insert_request." All said, a request-based DM multipath device's IO scheduler should be the only one used -- when the original requests are issued to the underlying paths as cloned requests they are inserted directly in the underlying dispatch queue(s) rather than through an additional elevator. But commit bd166ef18 ("blk-mq-sched: add framework for MQ capable IO schedulers") switched blk_insert_cloned_request() from using blk_mq_insert_request() to blk_mq_sched_insert_request(). Which incorrectly added elevator machinery into a call chain that isn't supposed to have any. To fix this introduce a blk-mq private blk_mq_request_bypass_insert() that blk_insert_cloned_request() calls to insert the request without involving any elevator that may be attached to the cloned request's request_queue. Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers") Cc: stable@vger.kernel.org Reported-by: Bart Van Assche <Bart.VanAssche@wdc.com> Tested-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-07Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer updates from Jens Axboe: "This is the first pull request for 4.14, containing most of the code changes. It's a quiet series this round, which I think we needed after the churn of the last few series. This contains: - Fix for a registration race in loop, from Anton Volkov. - Overflow complaint fix from Arnd for DAC960. - Series of drbd changes from the usual suspects. - Conversion of the stec/skd driver to blk-mq. From Bart. - A few BFQ improvements/fixes from Paolo. - CFQ improvement from Ritesh, allowing idling for group idle. - A few fixes found by Dan's smatch, courtesy of Dan. - A warning fixup for a race between changing the IO scheduler and device remova. From David Jeffery. - A few nbd fixes from Josef. - Support for cgroup info in blktrace, from Shaohua. - Also from Shaohua, new features in the null_blk driver to allow it to actually hold data, among other things. - Various corner cases and error handling fixes from Weiping Zhang. - Improvements to the IO stats tracking for blk-mq from me. Can drastically improve performance for fast devices and/or big machines. - Series from Christoph removing bi_bdev as being needed for IO submission, in preparation for nvme multipathing code. - Series from Bart, including various cleanups and fixes for switch fall through case complaints" * 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits) kernfs: checking for IS_ERR() instead of NULL drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set drbd: Fix allyesconfig build, fix recent commit drbd: switch from kmalloc() to kmalloc_array() drbd: abort drbd_start_resync if there is no connection drbd: move global variables to drbd namespace and make some static drbd: rename "usermode_helper" to "drbd_usermode_helper" drbd: fix race between handshake and admin disconnect/down drbd: fix potential deadlock when trying to detach during handshake drbd: A single dot should be put into a sequence. drbd: fix rmmod cleanup, remove _all_ debugfs entries drbd: Use setup_timer() instead of init_timer() to simplify the code. drbd: fix potential get_ldev/put_ldev refcount imbalance during attach drbd: new disk-option disable-write-same drbd: Fix resource role for newly created resources in events2 drbd: mark symbols static where possible drbd: Send P_NEG_ACK upon write error in protocol != C drbd: add explicit plugging when submitting batches drbd: change list_for_each_safe to while(list_first_entry_or_null) drbd: introduce drbd_recv_header_maybe_unplug ...
2017-08-18block: Fix two comments that refer to .queue_rq() return valuesBart Van Assche
Since patch "blk-mq: switch .queue_rq return value to blk_status_t" .queue_rq() returns a BLK_STS_* value instead of a BLK_MQ_RQ_* value. Hence refer to the former in comments about .queue_rq() return values. Fixes: commit 39a70c76b89b ("blk-mq: clarify dispatch may not be drained/blocked by stopping queue") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-15blk-mq: Fix queue usage on failed request allocationKeith Busch
blk_mq_get_request() does not release the callers queue usage counter when allocation fails. The caller still needs to account for its own queue usage when it is unable to allocate a request. Fixes: 1ad43c0078b7 ("blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed") Reported-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Tested-by: Max Gurtovoy <maxg@mellanox.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09block: Make blk_mq_delay_kick_requeue_list() rerun the queue at a quiet timeBart Van Assche
The blk_mq_delay_kick_requeue_list() function is used by the device mapper and only by the device mapper to rerun the queue and requeue list after a delay. This function is called once per request that gets requeued. Modify this function such that the queue is run once per path change event instead of once per request that is requeued. Fixes: commit 2849450ad39d ("blk-mq: introduce blk_mq_delay_kick_requeue_list()") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09blk-mq: enable checking two part inflight counts at the same timeJens Axboe
Modify blk_mq_in_flight() to count both a partition and root at the same time. Then we only have to call it once, instead of potentially looping the tags twice. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-09blk-mq: provide internal in-flight variantJens Axboe
We don't have to inc/dec some counter, since we can just iterate the tags. That makes inc/dec a noop, but means we have to iterate busy tags to get an in-flight count. Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-02blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failedMing Lei
When blk_mq_get_request() failed, preempt counter isn't released, and blk_mq_make_request() doesn't release the counter too. This patch fixes the issue, and makes sure that preempt counter is only held if rq is allocated successfully. The same policy is applied on .q_usage_counter too. Signed-off-by: Ming Lei <minlei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-01blk-mq: add warning to __blk_mq_run_hw_queue() for ints disabledJens Axboe
We recently had a bug in the IPR SCSI driver, where it would end up making the SCSI mid layer run the mq hardware queue with interrupts disabled. This isn't legal, since the software queue locking relies on never being grabbed from interrupt context. Additionally, drivers that set BLK_MQ_F_BLOCKING may schedule from this context. Add a WARN_ON_ONCE() to catch bad users up front. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-29blk-mq: blk_mq_requeue_work() doesn't need to save IRQ flagsJens Axboe
We know we're in process context, so don't bother using the IRQ safe versions of the spin lock. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-11Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull more block updates from Jens Axboe: "This is a followup for block changes, that didn't make the initial pull request. It's a bit of a mixed bag, this contains: - A followup pull request from Sagi for NVMe. Outside of fixups for NVMe, it also includes a series for ensuring that we properly quiesce hardware queues when browsing live tags. - Set of integrity fixes from Dmitry (mostly), fixing various issues for folks using DIF/DIX. - Fix for a bug introduced in cciss, with the req init changes. From Christoph. - Fix for a bug in BFQ, from Paolo. - Two followup fixes for lightnvm/pblk from Javier. - Depth fix from Ming for blk-mq-sched. - Also from Ming, performance fix for mtip32xx that was introduced with the dynamic initialization of commands" * 'for-linus' of git://git.kernel.dk/linux-block: (44 commits) block: call bio_uninit in bio_endio nvmet: avoid unneeded assignment of submit_bio return value nvme-pci: add module parameter for io queue depth nvme-pci: compile warnings in nvme_alloc_host_mem() nvmet_fc: Accept variable pad lengths on Create Association LS nvme_fc/nvmet_fc: revise Create Association descriptor length lightnvm: pblk: remove unnecessary checks lightnvm: pblk: control I/O flow also on tear down cciss: initialize struct scsi_req null_blk: fix error flow for shared tags during module_init block: Fix __blkdev_issue_zeroout loop nvme-rdma: unconditionally recycle the request mr nvme: split nvme_uninit_ctrl into stop and uninit virtio_blk: quiesce/unquiesce live IO when entering PM states mtip32xx: quiesce request queues to make sure no submissions are inflight nbd: quiesce request queues to make sure no submissions are inflight nvme: kick requeue list when requeueing a request instead of when starting the queues nvme-pci: quiesce/unquiesce admin_q instead of start/stop its hw queues nvme-loop: quiesce/unquiesce admin_q instead of start/stop its hw queues nvme-fc: quiesce/unquiesce admin_q instead of start/stop its hw queues ...
2017-07-03Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq department delivers: - Expand the generic infrastructure handling the irq migration on CPU hotplug and convert X86 over to it. (Thomas Gleixner) Aside of consolidating code this is a preparatory change for: - Finalizing the affinity management for multi-queue devices. The main change here is to shut down interrupts which are affine to a outgoing CPU and reenabling them when the CPU comes online again. That avoids moving interrupts pointlessly around and breaking and reestablishing affinities for no value. (Christoph Hellwig) Note: This contains also the BLOCK-MQ and NVME changes which depend on the rework of the irq core infrastructure. Jens acked them and agreed that they should go with the irq changes. - Consolidation of irq domain code (Marc Zyngier) - State tracking consolidation in the core code (Jeffy Chen) - Add debug infrastructure for hierarchical irq domains (Thomas Gleixner) - Infrastructure enhancement for managing generic interrupt chips via devmem (Bartosz Golaszewski) - Constification work all over the place (Tobias Klauser) - Two new interrupt controller drivers for MVEBU (Thomas Petazzoni) - The usual set of fixes, updates and enhancements all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (112 commits) irqchip/or1k-pic: Fix interrupt acknowledgement irqchip/irq-mvebu-gicp: Allocate enough memory for spi_bitmap irqchip/gic-v3: Fix out-of-bound access in gic_set_affinity nvme: Allocate queues for all possible CPUs blk-mq: Create hctx for each present CPU blk-mq: Include all present CPUs in the default queue mapping genirq: Avoid unnecessary low level irq function calls genirq: Set irq masked state when initializing irq_desc genirq/timings: Add infrastructure for estimating the next interrupt arrival time genirq/timings: Add infrastructure to track the interrupt timings genirq/debugfs: Remove pointless NULL pointer check irqchip/gic-v3-its: Don't assume GICv3 hardware supports 16bit INTID irqchip/gic-v3-its: Add ACPI NUMA node mapping irqchip/gic-v3-its-platform-msi: Make of_device_ids const irqchip/gic-v3-its: Make of_device_ids const irqchip/irq-mvebu-icu: Add new driver for Marvell ICU irqchip/irq-mvebu-gicp: Add new driver for Marvell GICP dt-bindings/interrupt-controller: Add DT binding for the Marvell ICU genirq/irqdomain: Remove auto-recursive hierarchy support irqchip/MSI: Use irq_domain_update_bus_token instead of an open coded access ...
2017-07-03bio-integrity: fold bio_integrity_enabled to bio_integrity_prepDmitry Monakhov
Currently all integrity prep hooks are open-coded, and if prepare fails we ignore it's code and fail bio with EIO. Let's return real error to upper layer, so later caller may react accordingly. In fact no one want to use bio_integrity_prep() w/o bio_integrity_enabled, so it is reasonable to fold it in to one function. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> [hch: merged with the latest block tree, return bool from bio_integrity_prep] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-03Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - Add the SYSTEM_SCHEDULING bootup state to move various scheduler debug checks earlier into the bootup. This turns silent and sporadically deadly bugs into nice, deterministic splats. Fix some of the splats that triggered. (Thomas Gleixner) - A round of restructuring and refactoring of the load-balancing and topology code (Peter Zijlstra) - Another round of consolidating ~20 of incremental scheduler code history: this time in terms of wait-queue nomenclature. (I didn't get much feedback on these renaming patches, and we can still easily change any names I might have misplaced, so if anyone hates a new name, please holler and I'll fix it.) (Ingo Molnar) - sched/numa improvements, fixes and updates (Rik van Riel) - Another round of x86/tsc scheduler clock code improvements, in hope of making it more robust (Peter Zijlstra) - Improve NOHZ behavior (Frederic Weisbecker) - Deadline scheduler improvements and fixes (Luca Abeni, Daniel Bristot de Oliveira) - Simplify and optimize the topology setup code (Lauro Ramos Venancio) - Debloat and decouple scheduler code some more (Nicolas Pitre) - Simplify code by making better use of llist primitives (Byungchul Park) - ... plus other fixes and improvements" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits) sched/cputime: Refactor the cputime_adjust() code sched/debug: Expose the number of RT/DL tasks that can migrate sched/numa: Hide numa_wake_affine() from UP build sched/fair: Remove effective_load() sched/numa: Implement NUMA node level wake_affine() sched/fair: Simplify wake_affine() for the single socket case sched/numa: Override part of migrate_degrades_locality() when idle balancing sched/rt: Move RT related code from sched/core.c to sched/rt.c sched/deadline: Move DL related code from sched/core.c to sched/deadline.c sched/cpuset: Only offer CONFIG_CPUSETS if SMP is enabled sched/fair: Spare idle load balancing on nohz_full CPUs nohz: Move idle balancer registration to the idle path sched/loadavg: Generalize "_idle" naming to "_nohz" sched/core: Drop the unused try_get_task_struct() helper function sched/fair: WARN() and refuse to set buddy when !se->on_rq sched/debug: Fix SCHED_WARN_ON() to return a value on !CONFIG_SCHED_DEBUG as well sched/wait: Disambiguate wq_entry->task_list and wq_head->task_list naming sched/wait: Move bit_wait_table[] and related functionality from sched/core.c to sched/wait_bit.c sched/wait: Split out the wait_bit*() APIs from <linux/wait.h> into <linux/wait_bit.h> sched/wait: Re-adjust macro line continuation backslashes in <linux/wait.h> ...
2017-06-28blk-mq: Create hctx for each present CPUChristoph Hellwig
Currently we only create hctx for online CPUs, which can lead to a lot of churn due to frequent soft offline / online operations. Instead allocate one for each present CPU to avoid this and dramatically simplify the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Cc: Keith Busch <keith.busch@intel.com> Cc: linux-block@vger.kernel.org Cc: linux-nvme@lists.infradead.org Link: http://lkml.kernel.org/r/20170626102058.10200-3-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-06-27blk-mq: don't bounce by defaultChristoph Hellwig
For historical reasons we default to bouncing highmem pages for all block queues. But the blk-mq drivers are easy to audit to ensure that we don't need this - scsi and mtip32xx set explicit limits and everyone else doesn't have any particular ones. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27block: don't bother with bounce limits for make_request driversChristoph Hellwig
We only call blk_queue_bounce for request-based drivers, so stop messing with it for make_request based drivers. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-24Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-22Merge commit '8e8320c9315c' into for-4.13/blockJens Axboe
Pull in the fix for shared tags, as it conflicts with the pending changes in for-4.13/block. We already pulled in v4.12-rc5 to solve other conflicts or get fixes that went into 4.12, so not a lot of changes in this merge. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-22blk-mq: remove double set queue_numweiping
hwctx's queue_num has been set prior call blk_mq_init_hctx, so no need set it again. Signed-off-by: weiping <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-21blk-mq: Make it safe to quiesce and unquiesce from an interrupt handlerBart Van Assche
Since blk_mq_quiesce_queue_nowait() can be called from interrupt context, make this safe. Since this function is not in the hot path, uninline it. Fixes: commit f4560ffe8cec ("blk-mq: use QUEUE_FLAG_QUIESCED to quiesce queue") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-21blk-mq: fix performance regression with shared tagsJens Axboe
If we have shared tags enabled, then every IO completion will trigger a full loop of every queue belonging to a tag set, and every hardware queue for each of those queues, even if nothing needs to be done. This causes a massive performance regression if you have a lot of shared devices. Instead of doing this huge full scan on every IO, add an atomic counter to the main queue that tracks how many hardware queues have been marked as needing a restart. With that, we can avoid looking for restartable queues, if we don't have to. Max reports that this restores performance. Before this patch, 4K IOPS was limited to 22-23K IOPS. With the patch, we are running at 950-970K IOPS. Fixes: 6d8c6c0f97ad ("blk-mq: Restart a single queue if tag sets are shared") Reported-by: Max Gurtovoy <maxg@mellanox.com> Tested-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Tested-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20blk-mq: Warn when attempting to run a hardware queue that is not mappedBart Van Assche
A queue must be frozen while the mapped state of a hardware queue is changed. Additionally, any change of the mapped state is followed by a call to blk_mq_map_swqueue() (see also blk_mq_init_allocated_queue() and blk_mq_update_nr_hw_queues()). Since blk_mq_map_swqueue() does not map any unmapped hardware queue onto any software queue, no attempt will be made to run an unmapped hardware queue. Hence issue a warning upon attempts to run an unmapped hardware queue. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20blk-mq: Document locking assumptionsBart Van Assche
Document the locking assumptions in functions that modify blk_mq_ctx.rq_list to make it easier for humans to verify this code. Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>