user/sven/linux.git/include/linux/sbitmap.h, branch v6.1.4

sbitmap: fix batched wait_cnt accounting

2022-09-12T06:10:34Z

Batched completions can clear multiple bits, but we're only decrementing the wait_cnt by one each time. This can cause waiters to never be woken, stalling IO. Use the batched count instead. Link: https://bugzilla.kernel.org/show_bug.cgi?id=215679 Signed-off-by: Keith Busch Link: https://lore.kernel.org/r/20220909184022.1709476-1-kbusch@fb.com Signed-off-by: Jens Axboe

Revert "sbitmap: fix batched wait_cnt accounting"

2022-09-04T12:39:25Z

This reverts commit 16ede66973c84f890c03584f79158dd5b2d725f5. This is causing issues with CPU stalls on my test box, revert it for now until we understand what is going on. It looks like infinite looping off sbitmap_queue_wake_up(), but hard to tell with a lot of CPUs hitting this issue and the console scrolling infinitely. Link: https://lore.kernel.org/linux-block/e742813b-ce5c-0d58-205b-1626f639b1bd@kernel.dk/ Signed-off-by: Jens Axboe

sbitmap: fix batched wait_cnt accounting

2022-09-01T16:42:41Z

Batched completions can clear multiple bits, but we're only decrementing the wait_cnt by one each time. This can cause waiters to never be woken, stalling IO. Use the batched count instead. Link: https://bugzilla.kernel.org/show_bug.cgi?id=215679 Signed-off-by: Keith Busch Link: https://lore.kernel.org/r/20220825145312.1217900-1-kbusch@fb.com Signed-off-by: Jens Axboe

lib/sbitmap: allocate sb->map via kvzalloc_node

2022-03-22T02:01:34Z

sbitmap has been used in scsi for replacing atomic operations on sdev->device_busy, so IOPS on some fast scsi storage can be improved. However, sdev->device_busy can be changed in fast path, so we have to allocate the sb->map statically. sdev->device_busy has been capped to 1024, but some drivers may configure the default depth as < 8, then cause each sbitmap word to hold only one bit. Finally 1024 * 128( sizeof(sbitmap_word)) bytes is needed for sb->map, given it is order 5 allocation, sometimes it may fail. Avoid the issue by using kvzalloc_node() for allocating sb->map. Cc: Ewan D. Milne Signed-off-by: Ming Lei Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20220316012708.354668-1-ming.lei@redhat.com Signed-off-by: Jens Axboe

sbitmap: Delete old sbitmap_queue_get_shallow()

2022-02-08T13:55:49Z

Since __sbitmap_queue_get_shallow() was introduced in commit c05e66733788 ("sbitmap: add sbitmap_get_shallow() operation"), it has not been used. Delete __sbitmap_queue_get_shallow() and rename public __sbitmap_queue_get_shallow() -> sbitmap_queue_get_shallow() as it is odd to have public __foo but no foo at all. Signed-off-by: John Garry Link: https://lore.kernel.org/r/1644322024-105340-1-git-send-email-john.garry@huawei.com Signed-off-by: Jens Axboe

lib/sbitmap: kill 'depth' from sbitmap_word

2022-02-08T13:54:50Z

Only the last sbitmap_word can have different depth, and all the others must have same depth of 1U << sb->shift, so not necessary to store it in sbitmap_word, and it can be retrieved easily and efficiently by adding one internal helper of __map_depth(sb, index). Remove 'depth' field from sbitmap_word, then the annotation of ____cacheline_aligned_in_smp for 'word' isn't needed any more. Not see performance effect when running high parallel IOPS test on null_blk. This way saves us one cacheline(usually 64 words) per each sbitmap_word. Cc: Martin Wilck Signed-off-by: Ming Lei Reviewed-by: Martin Wilck Reviewed-by: John Garry Link: https://lore.kernel.org/r/20220110072945.347535-1-ming.lei@redhat.com Signed-off-by: Jens Axboe

blk-mq: fix tag_get wait task can't be awakened

2022-01-13T19:52:14Z

In case of shared tags, there might be more than one hctx which allocates from the same tags, and each hctx is limited to allocate at most: hctx_max_depth = max((bt->sb.depth + users - 1) / users, 4U); tag idle detection is lazy, and may be delayed for 30sec, so there could be just one real active hctx(queue) but all others are actually idle and still accounted as active because of the lazy idle detection. Then if wake_batch is > hctx_max_depth, driver tag allocation may wait forever on this real active hctx. Fix this by recalculating wake_batch when inc or dec active_queues. Fixes: 0d2602ca30e41 ("blk-mq: improve support for shared tags maps") Suggested-by: Ming Lei Suggested-by: John Garry Signed-off-by: Laibin Qiu Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220113025536.1479653-1-qiulaibin@huawei.com Signed-off-by: Jens Axboe

Merge branch 'akpm' (patches from Andrew)

2021-11-09T18:11:53Z

Merge more updates from Andrew Morton: "87 patches. Subsystems affected by this patch series: mm (pagecache and hugetlb), procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs, init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork, sysvfs, kcov, gdb, resource, selftests, and ipc" * emailed patches from Andrew Morton : (87 commits) ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL ipc: check checkpoint_restore_ns_capable() to modify C/R proc files selftests/kselftest/runner/run_one(): allow running non-executable files virtio-mem: disallow mapping virtio-mem memory via /dev/mem kernel/resource: disallow access to exclusive system RAM regions kernel/resource: clean up and optimize iomem_is_exclusive() scripts/gdb: handle split debug for vmlinux kcov: replace local_irq_save() with a local_lock_t kcov: avoid enable+disable interrupts if !in_task() kcov: allocate per-CPU memory on the relevant node Documentation/kcov: define `ip' in the example Documentation/kcov: include types.h in the example sysv: use BUILD_BUG_ON instead of runtime check kernel/fork.c: unshare(): use swap() to make code cleaner seq_file: fix passing wrong private data seq_file: move seq_escape() to a header signal: remove duplicate include in signal.h crash_dump: remove duplicate include in crash_dump.h crash_dump: fix boolreturn.cocci warning hfs/hfsplus: use WARN_ON for sanity check ...

include/linux/sbitmap.h: replace kernel.h with the necessary inclusions

2021-11-09T18:02:49Z

When kernel.h is used in the headers it adds a lot into dependency hell, especially when there are circular dependencies are involved. Replace kernel.h inclusion with the list of what is really being used. Link: https://lkml.kernel.org/r/20211027150437.79921-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sbitmap: add helper to clear a batch of tags

2021-10-18T20:40:42Z

sbitmap currently only supports clearing tags one-by-one, add a helper that allows the caller to pass in an array of tags to clear. Signed-off-by: Jens Axboe