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* block: make bdev_ops->rw_page() take a REQ_OP instead of boolTejun Heo2018-07-187-33/+34
| | | | | | | | | | | | | | | | | | | c11f0c0b5bb9 ("block/mm: make bdev_ops->rw_page() take a bool for read/write") replaced @op with boolean @is_write, which limited the amount of information going into ->rw_page() and more importantly page_endio(), which removed the need to expose block internals to mm. Unfortunately, we want to track discards separately and @is_write isn't enough information. This patch updates bdev_ops->rw_page() to take REQ_OP instead but leaves page_endio() to take bool @is_write. This allows the block part of operations to have enough information while not leaking it to mm. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Mike Christie <mchristi@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* pktcdvd: remove assignment in if conditionRAGHU Halharvi2018-07-181-23/+46
| | | | | | | | * Remove checkpatch errors caused due to assignment operation in if condition Signed-off-by: RAGHU Halharvi <raghuhack78@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: issue directly if hw queue isn't busy in case of 'none'Ming Lei2018-07-183-2/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | In case of 'none' io scheduler, when hw queue isn't busy, it isn't necessary to enqueue request to sw queue and dequeue it from sw queue because request may be submitted to hw queue asap without extra cost, meantime there shouldn't be much request in sw queue, and we don't need to worry about effect on IO merge. There are still some single hw queue SCSI HBAs(HPSA, megaraid_sas, ...) which may connect high performance devices, so 'none' is often required for obtaining good performance. This patch improves IOPS and decreases CPU unilization on megaraid_sas, per Kashyap's test. Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: truncate our current timeJosef Bacik2018-07-161-0/+6
| | | | | | | | | | | | | In our longer tests we noticed that some boxes would degrade to the point of uselessness. This is because we truncate the current time when saving it in our bio, but I was using the raw current time to subtract from. So once the box had been up a certain amount of time it would appear as if our IO's were taking several years to complete. Fix this by truncating the current time so it matches the issue time. Verified this worked by running with this patch for a week on our test tier. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: don't change the latency windowJosef Bacik2018-07-161-10/+0
| | | | | | | | | | Early versions of these patches had us waiting for seconds at a time during submission, so we had to adjust the timing window we monitored for latency. Now we don't do things like that so this is unnecessary code. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: assume that chunks are closed on 1.2 devicesHans Holmberg2018-07-131-2/+3
| | | | | | | | | | We can't know if a block is closed or not on 1.2 devices, so assume closed state to make sure that blocks are erased before writing. Fixes: 32ef9412c114 ("lightnvm: pblk: implement get log report chunk") Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: add asynchronous partial readHeiner Litz2018-07-132-63/+130
| | | | | | | | | | | | In the read path, partial reads are currently performed synchronously which affects performance for workloads that generate many partial reads. This patch adds an asynchronous partial read path as well as the required partial read ctx. Signed-off-by: Heiner Litz <hlitz@ucsc.edu> Reviewed-by: Igor Konopko <igor.j.konopko@intel.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: mark expected switch fall-throughGustavo A. R. Silva2018-07-131-0/+1
| | | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: expose generic disk name on pr_* msgsMatias Bjørling2018-07-139-138/+153
| | | | | | | | | | | The error messages in pblk does not say which pblk instance that a message occurred from. Update each error message to reflect the instance it belongs to, and also prefix it with pblk, so we know the message comes from the pblk module. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: limit get chunk meta request sizeMatias Bjørling2018-07-131-2/+8
| | | | | | | | | | | | For devices that does not specify a limit on its transfer size, the get_chk_meta command may send down a single I/O retrieving the full chunk metadata table. Resulting in large 2-4MB I/O requests. Instead, split up the I/Os to a maximum of 256KB and issue them separately to reduce memory requirements. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: fix read_bitmap for 32bit archsMatias Bjørling2018-07-131-7/+7
| | | | | | | | | | | | | | If using pblk on a 32bit architecture, and there is a need to perform a partial read, the partial read bitmap will only have allocated 32 entries, where as 64 are needed. Make sure that the read_bitmap is initialized to 64bits on 32bit architectures as well. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Igor Konopko <igor.j.konopko@intel.com> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: Remove redundant rq->__data_len initializationBart Van Assche2018-07-131-4/+2
| | | | | | | | | | | Since both blk_old_get_request() and blk_mq_alloc_request() initialize rq->__data_len to zero, it is not necessary to initialize that member in nvme_nvm_alloc_request(). Hence remove the rq->__data_len initialization from nvme_nvm_alloc_request(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: enable line minor version detectionMatias Bjørling2018-07-131-2/+3
| | | | | | | | | | | | | | When recovering a line, an extra check was added when debugging was active, such that minor version where also checked. Unfortunately, this used the ifdef NVM_DEBUG, which is not correct. Instead use the proper DEBUG def, and now that it compiles, also fix the variable. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Fixes: d0ab0b1ab991f ("lightnvm: pblk: check data lines version on recovery") Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: move NVM_DEBUG to pblkMatias Bjørling2018-07-1310-70/+72
| | | | | | | | | | | | | There is no users of CONFIG_NVM_DEBUG in the LightNVM subsystem. All users are in pblk. Rename NVM_DEBUG to NVM_PBLK_DEBUG and enable only for pblk. Also fix up the CONFIG_NVM_PBLK entry to follow the code style for Kconfig files. Signed-off-by: Matias Bjørling <mb@lightnvm.io> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* lightnvm: pblk: handle case when mw_cunits equals to 0Marcin Dziegielewski2018-07-132-7/+5
| | | | | | | | | | | | | | | | | | | | | Some devices can expose mw_cunits equal to 0, it can cause the creation of too small write buffer and cause performance to drop on write workloads. Additionally, write buffer size must cover write data requirements, such as WS_MIN and MW_CUNITS - it must be greater than or equal to the larger one multiplied by the number of PUs. However, for performance reasons, use the WS_OPT value to calculation instead of WS_MIN. Because the place where buffer size is calculated was changed, this patch also removes pgs_in_buffer filed in pblk structure. Signed-off-by: Marcin Dziegielewski <marcin.dziegielewski@intel.com> Signed-off-by: Igor Konopko <igor.j.konopko@intel.com> Reviewed-by: Javier González <javier@cnexlabs.com> Signed-off-by: Matias Bjørling <mb@lightnvm.io> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: remove blkdev_entry_to_request() macroVladimir Zapolskiy2018-07-131-2/+0
| | | | | | | | | Remove blkdev_entry_to_request() macro, which remained unused through the observable history, also note that it repeats list_entry_rq() macro verbatim. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: skd: Use %pad printk format for dma_addr_t valuesHelge Deller2018-07-121-8/+8
| | | | | | | | | | | | Use the existing %pad printk format to print dma_addr_t values. This avoids the following warnings when compiling on the parisc64 platform: drivers/block/skd_main.c: In function 'skd_preop_sg_list': drivers/block/skd_main.c:660:4: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 6 has type 'dma_addr_t {aka unsigned int}' [-Wformat=] Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* bsg: remove read/write supportChristoph Hellwig2018-07-121-454/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The code poses a security risk due to user memory access in ->release and had an API that can't be used reliably. As far as we know it was never used for real, but if that turns out wrong we'll have to revert this commit and come up with a band aid. Jann Horn did look software archives for users of this interface, and the only users found were example code in sg3_utils, and optional support in an optional module of the tgt user space iscsi target, which looks like a proof of concept extension of the /dev/sg read/write support. Tony Battersby chimes in that the code is basically unsafe to use in general: The read/write interface on /dev/bsg is impossible to use safely because the list of completed commands is per-device (bd->done_list) rather than per-fd like it is with /dev/sg. So if program A and program B are both using the write/read interface on the same bsg device, then their command responses will get mixed up, and program A will read() some command results from program B and vice versa. So no, I don't use read/write on /dev/bsg. From a security standpoint, it should definitely be fixed or removed. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-iolatency: fix max_depth comparisonsJosef Bacik2018-07-111-6/+6
| | | | | | | | | | max_depth used to be a u64, but I changed it to a unsigned int but didn't convert my comparisons over everywhere. Fix by using UINT_MAX everywhere instead of (u64)-1. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: iolatency: avoid 64-bit divisionArnd Bergmann2018-07-101-2/+1
| | | | | | | | | | | | | | | | On 32-bit architectures, dividing a 64-bit number needs to use the do_div() function or something like it to avoid a link failure: block/blk-iolatency.o: In function `iolatency_prfill_limit': blk-iolatency.c:(.text+0x8cc): undefined reference to `__aeabi_uldivmod' Using div_u64() gives us the best output and avoids the need for an explicit cast. Fixes: d70675121546 ("block: introduce blk-iolatency io controller") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block/DAC960.c: fix defined but not used build warningsRandy Dunlap2018-07-091-3/+6
| | | | | | | | | | | | | | Fix build warnings in DAC960.c when CONFIG_PROC_FS is not enabled by marking the unused functions as __maybe_unused. ../drivers/block/DAC960.c:6429:12: warning: 'dac960_proc_show' defined but not used [-Wunused-function] ../drivers/block/DAC960.c:6449:12: warning: 'dac960_initial_status_proc_show' defined but not used [-Wunused-function] ../drivers/block/DAC960.c:6456:12: warning: 'dac960_current_status_proc_show' defined but not used [-Wunused-function] Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* null_blk: add zone supportMatias Bjørling2018-07-095-3/+234
| | | | | | | | | | | | | | Adds support for exposing a null_blk device through the zone device interface. The interface is managed with the parameters zoned and zone_size. If zoned is set, the null_blk instance registers as a zoned block device. The zone_size parameter defines how big each zone will be. Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* null_blk: move shared definitions to header fileMatias Bjørling2018-07-092-75/+81
| | | | | | | | Split the null_blk device driver, such that it can prepare for zoned block interface support. Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: Add default switch case to blk_pm_allow_request() to kill warningGeert Uytterhoeven2018-07-091-2/+2
| | | | | | | | | | | | | | | | | With gcc 4.9.0 and 7.3.0: block/blk-core.c: In function 'blk_pm_allow_request': block/blk-core.c:2747:2: warning: enumeration value 'RPM_ACTIVE' not handled in switch [-Wswitch] switch (rq->q->rpm_status) { ^ Convert the return statement below the switch() block into a default case to fix this. Fixes: e4f36b249b4d4e75 ("block: fix peeking requests during PM") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: fix infinite loop if the device loses discard capabilityMikulas Patocka2018-07-091-0/+10
| | | | | | | | | | | | | | | If __blkdev_issue_discard is in progress and a device mapper device is reloaded with a table that doesn't support discard, q->limits.max_discard_sectors is set to zero. This results in infinite loop in __blkdev_issue_discard. This patch checks if max_discard_sectors is zero and aborts with -EOPNOTSUPP. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Zdenek Kabelac <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block, mm: remove unnecessary __GFP_HIGH flagShakeel Butt2018-07-091-1/+1
| | | | | | | | The flag GFP_ATOMIC already contains __GFP_HIGH. There is no need to explicitly or __GFP_HIGH again. So, just remove unnecessary __GFP_HIGH. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* null_blk: remove NULLB_DEV_FL_CONFIGURED on turning off nullb deviceLiu Bo2018-07-091-0/+1
| | | | | | | | | | | | | | | | | | | Currently mbps knob could only be set once before switching power knob to on, after power knob has been set at least once, there is no way to set mbps knob again due to -EBUSY. As nullb is mainly used for testing, in order to make it flexible, this removes the flag NULLB_DEV_FL_CONFIGURED so that mbps knob can be reset when power knob is off, e.g. echo 0 > /config/nullb/a/power echo 40 > /config/nullb/a/mbps echo 1 > /config/nullb/a/power So does other knobs under /config/nullb/a. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* mm: skip readahead if the cgroup is congestedJosef Bacik2018-07-091-0/+7
| | | | | | | | | | | | | | We noticed in testing we'd get pretty bad latency stalls under heavy pressure because read ahead would try to do its thing while the cgroup was under severe pressure. If we're under this much pressure we want to do as little IO as possible so we can still make progress on real work if we're a throttled cgroup, so just skip readahead if our group is under pressure. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Documentation: add a doc for blk-iolatencyJosef Bacik2018-07-091-0/+79
| | | | | | | | A basic documentation to describe the interface, statistics, and behavior of io.latency. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: introduce blk-iolatency io controllerJosef Bacik2018-07-096-2/+957
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current IO controllers for the block layer are less than ideal for our use case. The io.max controller is great at hard limiting, but it is not work conserving. This patch introduces io.latency. You provide a latency target for your group and we monitor the io in short windows to make sure we are not exceeding those latency targets. This makes use of the rq-qos infrastructure and works much like the wbt stuff. There are a few differences from wbt - It's bio based, so the latency covers the whole block layer in addition to the actual io. - We will throttle all IO types that comes in here if we need to. - We use the mean latency over the 100ms window. This is because writes can be particularly fast, which could give us a false sense of the impact of other workloads on our protected workload. - By default there's no throttling, we set the queue_depth to INT_MAX so that we can have as many outstanding bio's as we're allowed to. Only at throttle time do we pay attention to the actual queue depth. - We backcharge cgroups for root cg issued IO and induce artificial delays in order to deal with cases like metadata only or swap heavy workloads. In testing this has worked out relatively well. Protected workloads will throttle noisy workloads down to 1 io at time if they are doing normal IO on their own, or induce up to a 1 second delay per syscall if they are doing a lot of root issued IO (metadata/swap IO). Our testing has revolved mostly around our production web servers where we have hhvm (the web server application) in a protected group and everything else in another group. We see slightly higher requests per second (RPS) on the test tier vs the control tier, and much more stable RPS across all machines in the test tier vs the control tier. Another test we run is a slow memory allocator in the unprotected group. Before this would eventually push us into swap and cause the whole box to die and not recover at all. With these patches we see slight RPS drops (usually 10-15%) before the memory consumer is properly killed and things recover within seconds. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* rq-qos: introduce dio_bio callbackJosef Bacik2018-07-093-0/+16
| | | | | | | | | | wbt cares only about request completion time, but controllers may need information that is on the bio itself, so add a done_bio callback for rq-qos so things like blk-iolatency can use it to have the bio when it completes. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: remove external dependency on wbt_flagsJosef Bacik2018-07-096-42/+68
| | | | | | | | | We don't really need to save this stuff in the core block code, we can just pass the bio back into the helpers later on to derive the same flags and update the rq->wbt_flags appropriately. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-rq-qos: refactor out common elements of blk-wbtJosef Bacik2018-07-0910-251/+478
| | | | | | | | | | blkcg-qos is going to do essentially what wbt does, only on a cgroup basis. Break out the common code that will be shared between blkcg-qos and wbt into blk-rq-qos.* so they can both utilize the same infrastructure. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-stat: export helpers for modifying blk_rq_statJosef Bacik2018-07-092-8/+12
| | | | | | | | | We need to use blk_rq_stat in the blkcg qos stuff, so export some of these helpers so they can be used by other things. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* memcontrol: schedule throttling if we are congestedTejun Heo2018-07-097-14/+81
| | | | | | | | | | | | | | | Memory allocations can induce swapping via kswapd or direct reclaim. If we are having IO done for us by kswapd and don't actually go into direct reclaim we may never get scheduled for throttling. So instead check to see if our cgroup is congested, and if so schedule the throttling. Before we return to user space the throttling stuff will only throttle if we actually required it. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blkcg: add generic throttling mechanismJosef Bacik2018-07-095-0/+332
| | | | | | | | | | | | | | | | | | | | | | | Since IO can be issued from literally anywhere it's almost impossible to do throttling without having some sort of adverse effect somewhere else in the system because of locking or other dependencies. The best way to solve this is to do the throttling when we know we aren't holding any other kernel resources. Do this by tracking throttling in a per-blkg basis, and if we require throttling flag the task that it needs to check before it returns to user space and possibly sleep there. This is to address the case where a process is doing work that is generating IO that can't be throttled, whether that is directly with a lot of REQ_META IO, or indirectly by allocating so much memory that it is swamping the disk with REQ_SWAP. We can't use task_add_work as we don't want to induce a memory allocation in the IO path, so simply saving the request queue in the task and flagging it to do the notify_resume thing achieves the same result without the overhead of a memory allocation. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* swap,blkcg: issue swap io with the appropriate contextTejun Heo2018-07-093-0/+32
| | | | | | | | | | | | | For backcharging we need to know who the page belongs to when swapping it out. We don't worry about things that do ->rw_page (zram etc) at the moment, we're only worried about pages that actually go to a block device. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk: introduce REQ_SWAPJosef Bacik2018-07-093-3/+4
| | | | | | | | | | | Just like REQ_META, it's important to know the IO coming down is swap in order to guard against potential IO priority inversion issues with cgroups. Add REQ_SWAP and use it for all swap IO, and add it to our bio_issue_as_root_blkg helper. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-cgroup: allow controllers to output their own statsJosef Bacik2018-07-092-3/+47
| | | | | | | | | | | | | | blk-iolatency has a few stats that it would like to print out, and instead of adding a bunch of crap to the generic code just provide a helper so that controllers can add stuff to the stat line if they want to. Hide it behind a boot option since it changes the output of io.stat from normal, and these stats are only interesting to developers. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: introduce bio_issue_as_root_blkgJosef Bacik2018-07-091-0/+16
| | | | | | | | | | | | | | Instead of forcing all file systems to get the right context on their bio's, simply check for REQ_META to see if we need to issue as the root blkg. We don't want to force all bio's to have the root blkg associated with them if REQ_META is set, as some controllers (blk-iolatency) need to know who the originating cgroup is so it can backcharge them for the work they are doing. This helper will make sure that the controllers do the proper thing wrt the IO priority and backcharging. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: add bi_blkg to the bio for cgroupsJosef Bacik2018-07-094-15/+32
| | | | | | | | | | | | | | | | | | | | | | | | Currently io.low uses a bi_cg_private to stash its private data for the blkg, however other blkcg policies may want to use this as well. Since we can get the private data out of the blkg, move this to bi_blkg in the bio and make it generic, then we can use bio_associate_blkg() to attach the blkg to the bio. Theoretically we could simply replace the bi_css with this since we can get to all the same information from the blkg, however you have to lookup the blkg, so for example wbc_init_bio() would have to lookup and possibly allocate the blkg for the css it was trying to attach to the bio. This could be problematic and result in us either not attaching the css at all to the bio, or falling back to the root blkcg if we are unable to allocate the corresponding blkg. So for now do this, and in the future if possible we could just replace the bi_css with bi_blkg and update the helpers to do the correct translation. Signed-off-by: Josef Bacik <jbacik@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: dequeue request one by one from sw queue if hctx is busyMing Lei2018-07-094-11/+45
| | | | | | | | | | | | | | | | | | | | | It won't be efficient to dequeue request one by one from sw queue, but we have to do that when queue is busy for better merge performance. This patch takes the Exponential Weighted Moving Average(EWMA) to figure out if queue is busy, then only dequeue request one by one from sw queue when queue is busy. Fixes: b347689ffbca ("blk-mq-sched: improve dispatching from sw queue") Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bart.vanassche@wdc.com> Cc: Hannes Reinecke <hare@suse.de> Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block/loop: mark expected switch fall-throughGustavo A. R. Silva2018-07-091-0/+1
| | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* drbd: mark expected switch fall-throughsGustavo A. R. Silva2018-07-091-0/+3
| | | | | | | | | | In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Warning level 2 was used in this case: -Wimplicit-fallthrough=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: only attempt to merge bio if there is rq in sw queueMing Lei2018-07-091-1/+2
| | | | | | | | | | | | | | | | | | | | | Only attempt to merge bio iff the ctx->rq_list isn't empty, because: 1) for high-performance SSD, most of times dispatch may succeed, then there may be nothing left in ctx->rq_list, so don't try to merge over sw queue if it is empty, then we can save one acquiring of ctx->lock 2) we can't expect good merge performance on per-cpu sw queue, and missing one merge on sw queue won't be a big deal since tasks can be scheduled from one CPU to another. Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Reported-by: Kashyap Desai <kashyap.desai@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: use list_splice_tail_init() to insert requestsMing Lei2018-07-091-7/+7
| | | | | | | | | | | | | | list_splice_tail_init() is much more faster than inserting each request one by one, given all requets in 'list' belong to same sw queue and ctx->lock is required to insert requests. Cc: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: fix typo in a function commentMinwoo Im2018-07-091-1/+1
| | | | | | | | Fix typo in a function blk_mq_alloc_tag_set() comment. if if it too large -> if it's too large. Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* blk-mq: code clean-up by adding an API to clear set->mq_mapMinwoo Im2018-07-093-5/+12
| | | | | | | | | | | set->mq_map is now currently cleared if something goes wrong when establishing a queue map in blk-mq-pci.c. It's also cleared before updating a queue map in blk_mq_update_queue_map(). This patch provides an API to clear set->mq_map to make it clear. Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* paride: remove redundant variable nColin Ian King2018-07-091-2/+1
| | | | | | | | | | | | Variable n is being assigned but is never used hence it is redundant and can be removed. Also put spacing between variables in declaration to clean up checkpatch warnings. Cleans up clang warning: warning: variable 'n' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* partitions/ldm: remove redundant pointer dgrpColin Ian King2018-07-091-3/+0
| | | | | | | | | | | Pointer dgrp is being assigned but is never used hence it is redundant and can be removed. Cleans up clang warning: warning: variable 'dgrp' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>