- 07 Sep, 2017 1 commit
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Tang Junhui authored
bcache uses a Proportion-Differentiation Controller algorithm to control writeback rate to cached devices. In the PD controller algorithm, dirty stripes of thin flash device should not be counted in, because flash only volumes never write back dirty data. Currently dirty stripe counter for thin flash device is not initialized when the thin flash device starts. Which means the following calculation in PD controller will reference an undefined dirty stripes number, and all cached devices attached to the same cache set where the thin flash device lies on may have an inaccurate writeback rate. This patch calles bch_sectors_dirty_init() in flash_dev_run(), to correctly initialize dirty stripe counter when the thin flash device starts to run. This patch also does following parameter data type change, -void bch_sectors_dirty_init(struct cached_dev *dc); +void bch_sectors_dirty_init(struct bcache_device *); to call this function conveniently in flash_dev_run(). (Commit log is composed by Coly Li) Signed-off-by:
Tang Junhui <tang.junhui@zte.com.cn> Reviewed-by:
Coly Li <colyli@suse.de> Cc: stable@vger.kernel.org Signed-off-by:
Jens Axboe <axboe@kernel.dk>
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- 06 Sep, 2017 13 commits
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Omar Sandoval authored
Commit 6c6b6f28 ("loop: set physical block size to PAGE_SIZE") caused mkfs.xfs to barf on ppc64 [1]. Always using PAGE_SIZE as the physical block size still makes the most sense semantically, but let's just lie and always set it to the same value as the logical block size (same goes for io_min). In the future we might want to at least bump up io_min to PAGE_SIZE but I'm sick of these stupid changes so let's play it safe. 1: https://marc.info/?l=linux-xfs&m=150459024723753&w=2Tested-by:
Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by:
Omar Sandoval <osandov@fb.com> Signed-off-by:
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Michael Lyle authored
Most importantly, solve a crash where %llu was used to format signed numbers. This would cause a buffer overflow when reading sysfs writeback_rate_debug, as only 20 bytes were allocated for this and %llu writes 20 characters plus a null. Always use the units mechanism rather than having different output paths for simplicity. Also, correct problems with display output where 1.10 was a larger number than 1.09, by multiplying by 10 and then dividing by 1024 instead of dividing by 100. (Remainders of >= 1000 would print as .10). Minor changes: Always display the decimal point instead of trying to omit it based on number of digits shown. Decide what units to use based on 1000 as a threshold, not 1024 (in other words, always print at most 3 digits before the decimal point). Signed-off-by:
Michael Lyle <mlyle@lyle.org> Reported-by:
Dmitry Yu Okunev <dyokunev@ut.mephi.ru> Acked-by:
Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by:
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Dan Carpenter authored
continue_at() doesn't have a return statement anymore. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Acked-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Dan Carpenter authored
In olden times, closure_return() used to have a hidden return built in. We removed the hidden return but forgot to add a new return here. If "c" were NULL we would oops on the next line, but fortunately "c" is never NULL. Let's just remove the if statement. Signed-off-by:
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Tang Junhui authored
gc and write-back get raced (see the email "bcache get stucked" I sended before): gc thread write-back thread | |bch_writeback_thread() |bch_gc_thread() | | |==>read_dirty() |==>bch_btree_gc() | |==>btree_root() //get btree root | | //node write locker | |==>bch_btree_gc_root() | | |==>read_dirty_submit() | |==>write_dirty() | |==>continue_at(cl, | | write_dirty_finish, | | system_wq); | |==>write_dirty_finish()//excute | | //in system_wq | |==>bch_btree_insert() | |==>bch_btree_map_leaf_nodes() | |==>__bch_btree_map_nodes() | |==>btree_root //try to get btree | | //root node read | | //lock | |-----stuck here |==>bch_btree_set_root() |==>bch_journal_meta() |==>bch_journal() |==>journal_try_write() |==>journal_write_unlocked() //journal_full(&c->journal) | //condition satisfied |==>continue_at(cl, journal_write, system_wq); //try to excute | //journal_write in system_wq | //but work queue is excuting | //write_dirty_finish() |==>closure_sync(); //wait journal_write execute | //over and wake up gc, |-------------stuck here |==>release root node write locker This patch alloc a separate work-queue for write-back thread to avoid such race. (Commit log re-organized by Coly Li to pass checkpatch.pl checking) Signed-off-by:
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Tang Junhui authored
In currently, we only alloc 6 open buckets for each cache set, but in usually, we always attach about 10 or so backend devices for each cache set, and the each bcache device are always accessed by about 10 or so threads in top application layer. So 6 open buckets are too few, It has led to that each of the same thread write data to different buckets, which would cause low efficiency write-back, and also cause buckets inefficient, and would be Very easy to run out of. I add debug message in bch_open_buckets_alloc() to print alloc bucket info, and test with ten bcache devices with a cache set, and each bcache device is accessed by ten threads. From the debug message, we can see that, after the modification, One bucket is more likely to assign to the same thread, and the data from the same thread are more likely to write the same bucket. Usually the same thread always write/read the same backend device, so it is good for write-back and also promote the usage efficiency of buckets. Signed-off-by:
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Tony Asleson authored
If you encounter any errors in bch_cached_dev_attach it will return a negative error code. The variable 'v' which stores the result is unsigned, thus user space sees a very large value returned for bytes written which can cause incorrect user space behavior. Utilize 1 signed variable to use throughout the function to preserve error return capability. Signed-off-by:
Tony Asleson <tasleson@redhat.com> Acked-by:
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Tang Junhui authored
__update_write_rate() uses a Proportion-Differentiation Controller algorithm to control writeback rate. A dirty target number is used in this PD controller to control writeback rate. A larger target number will make the writeback rate smaller, on the versus, a smaller target number will make the writeback rate larger. bcache uses the following steps to calculate the target number, 1) cache_sectors = all-buckets-of-cache-set * buckets-size 2) cache_dirty_target = cache_sectors * cached-device-writeback_percent 3) target = cache_dirty_target * (sectors-of-cached-device/sectors-of-all-cached-devices-of-this-cache-set) The calculation at step 1) for cache_sectors is incorrect, which does not consider dirty blocks occupied by flash only volume. A flash only volume can be took as a bcache device without cached device. All data sectors allocated for it are persistent on cache device and marked dirty, they are not touched by bcache writeback and garbage collection code. So data blocks of flash only volume should be ignore when calculating cache_sectors of cache set. Current code does not subtract dirty sectors of flash only volume, which results a larger target number from the above 3 steps. And in sequence the cache device's writeback rate is smaller then a correct value, writeback speed is slower on all cached devices. This patch fixes the incorrect slower writeback rate by subtracting dirty sectors of flash only volumes in __update_writeback_rate(). (Commit log composed by Coly Li to pass checkpatch.pl checking) Signed-off-by:
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Tang Junhui authored
I try to execute the following command to trigger gc thread: [root@localhost internal]# echo 1 > trigger_gc But it does not work, I debug the code in gc_should_run(), It works only if in invalidating or sectors_to_gc < 0. So set sectors_to_gc to -1 to meet the condition when we trigger gc by manual command. (Code comments aded by Coly Li) Signed-off-by:
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Byungchul Park authored
Although llist provides proper APIs, they are not used. Make them used. Signed-off-by:
Byungchul Park <byungchul.park@lge.com> Acked-by:
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Tang Junhui authored
Since bypassed IOs use no bucket, so do not subtract sectors_to_gc to trigger gc thread. Signed-off-by:
Eric Wheeler <bcache@linux.ewheeler.net> Reviewed-by:
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Tang Junhui authored
Sequential write IOs were tested with bs=1M by FIO in writeback cache mode, these IOs were expected to be bypassed, but actually they did not. We debug the code, and find in check_should_bypass(): if (!congested && mode == CACHE_MODE_WRITEBACK && op_is_write(bio_op(bio)) && (bio-＞bi_opf & REQ_SYNC)) goto rescale that means, If in writeback mode, a write IO with REQ_SYNC flag will not be bypassed though it is a sequential large IO, It's not a correct thing to do actually, so this patch remove these codes. Signed-off-by: -
Jan Kara authored
If blkdev_get_by_path() in register_bcache() fails, we try to lookup the block device using lookup_bdev() to detect which situation we are in to properly report error. However we never drop the reference returned to us from lookup_bdev(). Fix that. Signed-off-by:
Jan Kara <jack@suse.cz> Acked-by:
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- 01 Sep, 2017 11 commits
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Shaohua Li authored
nobody uses the list. Signed-off-by:
Shaohua Li <shli@fb.com> Signed-off-by:
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Shaohua Li authored
lo_rw_aio->call_read_iter-> 1 aops->direct_IO 2 iov_iter_revert lo_rw_aio_complete could happen between 1 and 2, the bio and bvec could be freed before 2, which accesses bvec. Signed-off-by:
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Bart Van Assche authored
Some code uses icq_to_bic() to convert an io_cq pointer to a bfq_io_cq pointer while other code uses a direct cast. Convert the code that uses a direct cast such that it uses icq_to_bic(). Acked-by:
Paolo Valente <paolo.valente@linaro.org> Signed-off-by:
Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by:
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Bart Van Assche authored
This patch avoids that the following warnings are reported when building with W=1: block/bfq-iosched.c: In function 'bfq_back_seek_max_store': block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] if (__data < (MIN)) \ ^ block/bfq-iosched.c:4876:1: note: in expansion of macro 'STORE_FUNCTION' STORE_FUNCTION(bfq_back_seek_max_store, &bfqd->bfq_back_max, 0, INT_MAX, 0); ^~~~~~~~~~~~~~ block/bfq-iosched.c: In function 'bfq_slice_idle_store': block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] if (__data < (MIN)) \ ^ block/bfq-iosched.c:4879:1: note: in expansion of macro 'STORE_FUNCTION' STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2); ^~~~~~~~~~~~~~ block/bfq-iosched.c: In function 'bfq_slice_idle_us_store': block/bfq-iosched.c:4892:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] if (__data < (MIN)) \ ^ block/bfq-iosched.c:4899:1: note: in expansion of macro 'USEC_STORE_FUNCTION' USEC_STORE_FUNCTION(bfq_slice_idle_us_store, &bfqd->bfq_slice_idle, 0, ^~~~~~~~~~~~~~~~~~~ Acked-by: -
Bart Van Assche authored
Make sysfs writes fail for invalid numbers instead of storing uninitialized data copied from the stack. This patch removes all uninitialized_var() occurrences from the BFQ source code. Acked-by:
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Bart Van Assche authored
Acked-by:
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Bart Van Assche authored
This patch avoids that gcc 7 issues a warning about fall-through when building with W=1. Acked-by:
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git://git.infradead.org/nvmeJens Axboe authored
Pull NVMe updates from Christoph: "A few more nvme updates for 4.14: - generate a correct default NQN (Daniel Verkamp) - metadata passthrough for the NVME_IOCTL_IO_CMD ioctl, as well as related fixes and cleanups (Keith) - better scalability for connecting to the NVMeOF target (Roland Dreier) - target support for reading the host identifier (Omri Mann)"
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Shaohua Li authored
Currently loop disables merge. While it makes sense for buffer IO mode, directio mode can benefit from request merge. Without merge, loop could send small size IO to underlayer disk and harm performance. Reviewed-by:
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Shaohua Li authored
Loop can handle any size of request. Limiting it to 255 sectors just burns the CPU for bio split and request merge for underlayer disk and also cause bad fs block allocation in directio mode. Reviewed-by:
Ming Lei <ming.lei@redhat.com> Signed-off-by:
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Daniel Verkamp authored
The default host NQN, which is generated based on the host's UUID, does not follow the UUID-based NQN format laid out in the NVMe 1.3 specification. Remove the "NVMf:" portion of the NQN to match the spec. Signed-off-by:
Daniel Verkamp <daniel.verkamp@intel.com> Reviewed-by:
Max Gurtovoy <maxg@mellanox.com> Cc: stable@vger.kernel.org Signed-off-by:
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- 31 Aug, 2017 9 commits
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Paolo Valente authored
Many users have reported the lack of an HOWTO for properly configuring bfq as a function of the goal one wants to achieve (max responsiveness, max throughput, ...). In fact, all needed details are already provided in the documentation file bfq-iosched.txt. Yet the document lacks guidance on which parameter descriptions to look at. This commit adds some simple direction. Signed-off-by:
Jeremy Hickman <jeremywh7@gmail.com> Reviewed-by:
Laurentiu Nicola <lnicola@dend.ro> Signed-off-by:
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Paolo Valente authored
In addition to containing some typos and stale sentences, the file bfq-iosched.txt still mentioned a set of sysfs parameters that have been removed from this version of bfq. This commit fixes all these issues. Signed-off-by:
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Omar Sandoval authored
The comments here are really outdated, and blk-mq made flushing much simpler, so just fold the two cases into the callers. Reviewed-by:
Hannes Reinecke <hare@suse.com> Signed-off-by:
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Omar Sandoval authored
This is a different approach from the first attempt in f2c6df7d ("loop: support 4k physical blocksize"). Rather than extending LOOP_{GET,SET}_STATUS, add a separate ioctl just for setting the block size. Reviewed-by:
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Omar Sandoval authored
The physical block size is "the lowest possible sector size that the hardware can operate on without reverting to read-modify-write operations" (from the comment on blk_queue_physical_block_size()). Since loop does buffered I/O on the backing file by default, the RMW unit is a page. This isn't the case for direct I/O mode, but let's keep it simple. Reviewed-by:
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Omar Sandoval authored
This is only used for setting the soft block size on the struct block_device once and then never used again. Reviewed-by:
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Paolo Valente authored
If the function bfq_update_next_in_service is invoked as a consequence of the activation or requeueing of an entity, say E, then it doesn't invoke bfq_lookup_next_entity to get the next-in-service entity. In contrast, it follows a shorter path: if E happens to be eligible (see commit "bfq-sq-mq: make lookup_next_entity push up vtime on expirations" for details on eligibility) and to have a lower virtual finish time than the current candidate as next-in-service entity, then E directly becomes the next-in-service entity. Unfortunately, there is a corner case for which this shorter path makes bfq_update_next_in_service choose a non eligible entity: it occurs if both E and the current next-in-service entity happen to be non eligible when bfq_update_next_in_service is invoked. In this case, E is not set as next-in-service, and, since bfq_lookup_next_entity is not invoked, the state of the parent entity is not updated so as to end up with an eligible entity as the proper next-in-service entity. In this respect, next-in-service is actually allowed to be non eligible while some queue is in service: since no system-virtual-time push-up can be performed in that case (see again commit "bfq-sq-mq: make lookup_next_entity push up vtime on expirations" for details), next-in-service is chosen, speculatively, as a function of the possible value that the system virtual time may get after a push up. But the correctness of the schedule breaks if next-in-service is still a non eligible entity when it is time to set in service the next entity. Unfortunately, this may happen in the above corner case. This commit fixes this problem by making bfq_update_next_in_service invoke bfq_lookup_next_entity not only if the above shorter path cannot be taken, but also if the shorter path is taken but fails to yield an eligible next-in-service entity. Signed-off-by:
Lee Tibbert <lee.tibbert@gmail.com> Tested-by:
Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by:
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Paolo Valente authored
If the function bfq_update_next_in_service is invoked as a consequence of the activation or requeueing of an entity, say E, and finds out that E belongs to a higher-priority class than that of the current next-in-service entity, then it sets next_in_service directly to E. But this may lead to anomalous schedules, because E may happen not be eligible for service, because its virtual start time is higher than the system virtual time for its service tree. This commit addresses this issue by simply removing this direct switch. Signed-off-by:
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Paolo Valente authored
To provide a very smooth service, bfq starts to serve a bfq_queue only if the queue is 'eligible', i.e., if the same queue would have started to be served in the ideal, perfectly fair system that bfq simulates internally. This is obtained by associating each queue with a virtual start time, and by computing a special system virtual time quantity: a queue is eligible only if the system virtual time has reached the virtual start time of the queue. Finally, bfq guarantees that, when a new queue must be set in service, there is always at least one eligible entity for each active parent entity in the scheduler. To provide this guarantee, the function __bfq_lookup_next_entity pushes up, for each parent entity on which it is invoked, the system virtual time to the minimum among the virtual start times of the entities in the active tree for the parent entity (more precisely, the push up occurs if the system virtual time happens to be lower than all such virtual start times). There is however a circumstance in which __bfq_lookup_next_entity cannot push up the system virtual time for a parent entity, even if the system virtual time is lower than the virtual start times of all the child entities in the active tree. It happens if one of the child entities is in service. In fact, in such a case, there is already an eligible entity, the in-service one, even if it may not be not present in the active tree (because in-service entities may be removed from the active tree). Unfortunately, in the last re-design of the hierarchical-scheduling engine, the reset of the pointer to the in-service entity for a given parent entity--reset to be done as a consequence of the expiration of the in-service entity--always happens after the function __bfq_lookup_next_entity has been invoked. This causes the function to think that there is still an entity in service for the parent entity, and then that the system virtual time cannot be pushed up, even if actually such a no-more-in-service entity has already been properly reinserted into the active tree (or in some other tree if no more active). Yet, the system virtual time *had* to be pushed up, to be ready to correctly choose the next queue to serve. Because of the lack of this push up, bfq may wrongly set in service a queue that had been speculatively pre-computed as the possible next-in-service queue, but that would no more be the one to serve after the expiration and the reinsertion into the active trees of the previously in-service entities. This commit addresses this issue by making __bfq_lookup_next_entity properly push up the system virtual time if an expiration is occurring. Signed-off-by:
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- 30 Aug, 2017 6 commits
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Omri Mann authored
And fix the Get/Set Log Page implementation to take all 8 bits of the feature identifier into account. Signed-off-by:
Omri Mann <omri@excelero.com> Reviewed-by:
Sagi Grimberg <sagi@grimberg.me> Signed-off-by:
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Keith Busch authored
The ioctls' struct allows the user to provide a metadata address and length for a passthrough command. This patch uses these values that were previously ignored and deletes the now unused wrapper function. Signed-off-by:
Keith Busch <keith.busch@intel.com> Reviewed-by:
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Keith Busch authored
These functions are used only locally in the nvme core. Signed-off-by:
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Keith Busch authored
Only read and write commands need DIF remapping. Everything else uses a passthrough integrity payload. Signed-off-by:
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Christoph Hellwig authored
Keep the metadata code in a separate helper instead of making the main function more complicated. Signed-off-by:
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Roland Dreier authored
The mutex protects against the list of transports changing while a controller is being created, but using a plain old mutex means that it also serializes controller creation. This unnecessarily slows down creating multiple controllers - for example for the RDMA transport, creating a controller involves establishing one connection for every IO queue, which involves even more network/software round trips, so the delay can become significant. The simplest way to fix this is to change the mutex to an rwsem and only hold it for writing when the list is being mutated. Since we can take the rwsem for reading while creating a controller, we can create multiple controllers in parallel. Signed-off-by:
Roland Dreier <roland@purestorage.com> Reviewed-by:
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