From: Shushu Yi <firnyee@xxxxxxxxx> Optimized by using fine-grained locks, customized data structures, and scattered address space. Achieves significant improvements in both throughput and latency. This patch attempts to maximize thread-level parallelism and reduce CPU suspension time caused by lock contention. On a system with four PCIe 4.0 SSDs, we achieved increased overall storage throughput by 89.4% and decreases the 99.99th percentile I/O latency by 85.4%. Seeking feedback on the approach and any addition information regarding Required performance testing before submitting a formal patch. Note: this work has been published as a paper, and the URL is https://www.hotstorage.org/2022/camera-ready/hotstorage22-5/pdf/hotstorage22-5.pdf Co-developed-by: Yiming Xu <teddyxym@xxxxxxxxxxx> Signed-off-by: Yiming Xu <teddyxym@xxxxxxxxxxx> Signed-off-by: Shushu Yi <firnyee@xxxxxxxxx> --- diff -uprN origlinux-6.6.1/drivers/md/md-bitmap.c linux-6.6.1/drivers/md/md-bitmap.c --- origlinux-6.6.1/drivers/md/md-bitmap.c 2023-11-13 20:48:43.410856322 +0800 +++ linux-6.6.1/drivers/md/md-bitmap.c 2023-11-13 23:24:24.360653915 +0800 @@ -48,9 +48,11 @@ static inline char *bmname(struct bitmap * allocated while we're using it */ static int md_bitmap_checkpage(struct bitmap_counts *bitmap, - unsigned long page, int create, int no_hijack) -__releases(bitmap->lock) -__acquires(bitmap->lock) + unsigned long page, int create, int no_hijack, spinlock_t *bmclock, int locktype) +__releases(bmclock) +__acquires(bmclock) +__releases(bitmap->mlock) +__acquires(bitmap->mlock) { unsigned char *mappage; @@ -65,8 +67,10 @@ __acquires(bitmap->lock) return -ENOENT; /* this page has not been allocated yet */ - - spin_unlock_irq(&bitmap->lock); + if (locktype) + spin_unlock_irq(bmclock); + else + write_unlock_irq(&bitmap->mlock); /* It is possible that this is being called inside a * prepare_to_wait/finish_wait loop from raid5c:make_request(). * In general it is not permitted to sleep in that context as it @@ -81,7 +85,11 @@ __acquires(bitmap->lock) */ sched_annotate_sleep(); mappage = kzalloc(PAGE_SIZE, GFP_NOIO); - spin_lock_irq(&bitmap->lock); + + if (locktype) + spin_lock_irq(bmclock); + else + write_lock_irq(&bitmap->mlock); if (mappage == NULL) { pr_debug("md/bitmap: map page allocation failed, hijacking\n"); @@ -398,7 +406,7 @@ static int read_file_page(struct file *f } wait_event(bitmap->write_wait, - atomic_read(&bitmap->pending_writes)==0); + atomic_read(&bitmap->pending_writes) == 0); if (test_bit(BITMAP_WRITE_ERROR, &bitmap->flags)) ret = -EIO; out: @@ -457,7 +465,7 @@ static void md_bitmap_wait_writes(struct { if (bitmap->storage.file) wait_event(bitmap->write_wait, - atomic_read(&bitmap->pending_writes)==0); + atomic_read(&bitmap->pending_writes) == 0); else /* Note that we ignore the return value. The writes * might have failed, but that would just mean that @@ -1246,16 +1254,32 @@ void md_bitmap_write_all(struct bitmap * static void md_bitmap_count_page(struct bitmap_counts *bitmap, sector_t offset, int inc) { - sector_t chunk = offset >> bitmap->chunkshift; - unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + sector_t blockno = offset >> (PAGE_SHIFT - SECTOR_SHIFT); + sector_t totblocks = bitmap->chunks << (bitmap->chunkshift - (PAGE_SHIFT - SECTOR_SHIFT)); + unsigned long bits = totblocks ? fls((totblocks - 1)) : 0; + unsigned long mask = ULONG_MAX << bits | ~(ULONG_MAX << (bits - (bitmap->chunkshift + SECTOR_SHIFT - PAGE_SHIFT))); + unsigned long cntid = blockno & mask; + unsigned long page = cntid >> PAGE_COUNTER_SHIFT; + + // sector_t chunk = offset >> bitmap->chunkshift; + // unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + bitmap->bp[page].count += inc; md_bitmap_checkfree(bitmap, page); } static void md_bitmap_set_pending(struct bitmap_counts *bitmap, sector_t offset) { - sector_t chunk = offset >> bitmap->chunkshift; - unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + sector_t blockno = offset >> (PAGE_SHIFT - SECTOR_SHIFT); + sector_t totblocks = bitmap->chunks << (bitmap->chunkshift - (PAGE_SHIFT - SECTOR_SHIFT)); + unsigned long bits = totblocks ? fls((totblocks - 1)) : 0; + unsigned long mask = ULONG_MAX << bits | ~(ULONG_MAX << (bits - (bitmap->chunkshift + SECTOR_SHIFT - PAGE_SHIFT))); + unsigned long cntid = blockno & mask; + unsigned long page = cntid >> PAGE_COUNTER_SHIFT; + + // sector_t chunk = offset >> bitmap->chunkshift; + // unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + struct bitmap_page *bp = &bitmap->bp[page]; if (!bp->pending) @@ -1264,7 +1288,7 @@ static void md_bitmap_set_pending(struct static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap, sector_t offset, sector_t *blocks, - int create); + int create, spinlock_t *bmclock, int locktype); static void mddev_set_timeout(struct mddev *mddev, unsigned long timeout, bool force) @@ -1349,7 +1373,7 @@ void md_bitmap_daemon_work(struct mddev * decrement and handle accordingly. */ counts = &bitmap->counts; - spin_lock_irq(&counts->lock); + write_lock_irq(&counts->mlock); nextpage = 0; for (j = 0; j < counts->chunks; j++) { bitmap_counter_t *bmc; @@ -1364,7 +1388,7 @@ void md_bitmap_daemon_work(struct mddev counts->bp[j >> PAGE_COUNTER_SHIFT].pending = 0; } - bmc = md_bitmap_get_counter(counts, block, &blocks, 0); + bmc = md_bitmap_get_counter(counts, block, &blocks, 0, 0, 0); if (!bmc) { j |= PAGE_COUNTER_MASK; continue; @@ -1380,7 +1404,7 @@ void md_bitmap_daemon_work(struct mddev bitmap->allclean = 0; } } - spin_unlock_irq(&counts->lock); + write_unlock_irq(&counts->mlock); md_bitmap_wait_writes(bitmap); /* Now start writeout on any page in NEEDWRITE that isn't DIRTY. @@ -1413,17 +1437,27 @@ void md_bitmap_daemon_work(struct mddev static bitmap_counter_t *md_bitmap_get_counter(struct bitmap_counts *bitmap, sector_t offset, sector_t *blocks, - int create) -__releases(bitmap->lock) -__acquires(bitmap->lock) + int create, spinlock_t *bmclock, int locktype) +__releases(bmclock) +__acquires(bmclock) +__releases(bitmap->mlock) +__acquires(bitmap->mlock) { /* If 'create', we might release the lock and reclaim it. * The lock must have been taken with interrupts enabled. * If !create, we don't release the lock. */ - sector_t chunk = offset >> bitmap->chunkshift; - unsigned long page = chunk >> PAGE_COUNTER_SHIFT; - unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; + sector_t blockno = offset >> (PAGE_SHIFT - SECTOR_SHIFT); + sector_t totblocks = bitmap->chunks << (bitmap->chunkshift - (PAGE_SHIFT - SECTOR_SHIFT)); + unsigned long bits = totblocks ? fls((totblocks - 1)) : 0; + unsigned long mask = ULONG_MAX << bits | ~(ULONG_MAX << (bits - (bitmap->chunkshift + SECTOR_SHIFT - PAGE_SHIFT))); + unsigned long cntid = blockno & mask; + unsigned long page = cntid >> PAGE_COUNTER_SHIFT; + unsigned long pageoff = (cntid & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; + + // sector_t chunk = offset >> bitmap->chunkshift; + // unsigned long page = chunk >> PAGE_COUNTER_SHIFT; + // unsigned long pageoff = (chunk & PAGE_COUNTER_MASK) << COUNTER_BYTE_SHIFT; sector_t csize; int err; @@ -1435,7 +1469,7 @@ __acquires(bitmap->lock) */ return NULL; } - err = md_bitmap_checkpage(bitmap, page, create, 0); + err = md_bitmap_checkpage(bitmap, page, create, 0, bmclock, 1); if (bitmap->bp[page].hijacked || bitmap->bp[page].map == NULL) @@ -1461,6 +1495,36 @@ __acquires(bitmap->lock) &(bitmap->bp[page].map[pageoff]); } +/* set-association + * e.g. if we have 14 counters & BITMAP_COUNTER_LOCK_RATIO_SHIFT is 2 (means every 2^2 counters share the same lock), + * counter 0, 4, 8 and 12 share the same lock. (1, 5, 9, 13 | 2, 6, 10) + */ +static spinlock_t *md_bitmap_get_bmclock(struct bitmap_counts *bitmap, sector_t offset); + +static spinlock_t *md_bitmap_get_bmclock(struct bitmap_counts *bitmap, sector_t offset) +{ + sector_t blockno = offset >> (PAGE_SHIFT - SECTOR_SHIFT); + sector_t totblocks = bitmap->chunks << (bitmap->chunkshift - (PAGE_SHIFT - SECTOR_SHIFT)); + unsigned long bitscnt = totblocks ? fls((totblocks - 1)) : 0; + unsigned long maskcnt = ULONG_MAX << bitscnt | ~(ULONG_MAX << (bitscnt - (bitmap->chunkshift + SECTOR_SHIFT - PAGE_SHIFT))); + unsigned long cntid = blockno & maskcnt; + + unsigned long totcnts = bitmap->chunks; + unsigned long bitslock = totcnts ? fls((totcnts - 1)) : 0; + unsigned long masklock = ULONG_MAX << bitslock | ~(ULONG_MAX << (bitslock - BITMAP_COUNTER_LOCK_RATIO_SHIFT)); + unsigned long lockid = cntid & masklock; + + // unsigned long chunks = bitmap->chunks; /* Total number of (bitmap) chunks for the array */ + // sector_t chunk = offset >> bitmap->chunkshift; + // unsigned long bits = chunks ? fls((chunks - 1)) : 0; + // unsigned long mask = ULONG_MAX << bits | ~(ULONG_MAX << (bits - BITMAP_COUNTER_LOCK_RATIO_SHIFT)); + // unsigned long lockidx = chunk & mask; + + spinlock_t *bmclock = &(bitmap->bmclocks[lockid]); + pr_debug("========>>> offset =%lld, blockno = %lld, totblocks = %lld ,totcnts = %ld, cntid = %ld, lockidx = %ld", offset, blockno, totblocks, totcnts, cntid, lockid); + return bmclock; +} + int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sectors, int behind) { if (!bitmap) @@ -1480,11 +1544,15 @@ int md_bitmap_startwrite(struct bitmap * while (sectors) { sector_t blocks; bitmap_counter_t *bmc; + spinlock_t *bmclock; - spin_lock_irq(&bitmap->counts.lock); - bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1); + bmclock = md_bitmap_get_bmclock(&bitmap->counts, offset); + read_lock(&bitmap->counts.mlock); + spin_lock_irq(bmclock); + bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 1, bmclock, 1); if (!bmc) { - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); return 0; } @@ -1496,7 +1564,8 @@ int md_bitmap_startwrite(struct bitmap * */ prepare_to_wait(&bitmap->overflow_wait, &__wait, TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); schedule(); finish_wait(&bitmap->overflow_wait, &__wait); continue; @@ -1513,7 +1582,8 @@ int md_bitmap_startwrite(struct bitmap * (*bmc)++; - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); offset += blocks; if (sectors > blocks) @@ -1542,11 +1612,15 @@ void md_bitmap_endwrite(struct bitmap *b sector_t blocks; unsigned long flags; bitmap_counter_t *bmc; + spinlock_t *bmclock; - spin_lock_irqsave(&bitmap->counts.lock, flags); - bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0); + bmclock = md_bitmap_get_bmclock(&bitmap->counts, offset); + read_lock(&bitmap->counts.mlock); + spin_lock_irqsave(bmclock, flags); + bmc = md_bitmap_get_counter(&bitmap->counts, offset, &blocks, 0, bmclock, 1); if (!bmc) { - spin_unlock_irqrestore(&bitmap->counts.lock, flags); + spin_unlock_irqrestore(bmclock, flags); + read_unlock(&bitmap->counts.mlock); return; } @@ -1568,7 +1642,8 @@ void md_bitmap_endwrite(struct bitmap *b md_bitmap_set_pending(&bitmap->counts, offset); bitmap->allclean = 0; } - spin_unlock_irqrestore(&bitmap->counts.lock, flags); + spin_unlock_irqrestore(bmclock, flags); + read_unlock(&bitmap->counts.mlock); offset += blocks; if (sectors > blocks) sectors -= blocks; @@ -1582,13 +1657,16 @@ static int __bitmap_start_sync(struct bi int degraded) { bitmap_counter_t *bmc; + spinlock_t *bmclock; int rv; if (bitmap == NULL) {/* FIXME or bitmap set as 'failed' */ *blocks = 1024; return 1; /* always resync if no bitmap */ } - spin_lock_irq(&bitmap->counts.lock); - bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0); + bmclock = md_bitmap_get_bmclock(&bitmap->counts, offset); + read_lock(&bitmap->counts.mlock); + spin_lock_irq(bmclock); + bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0, bmclock, 1); rv = 0; if (bmc) { /* locked */ @@ -1602,7 +1680,8 @@ static int __bitmap_start_sync(struct bi } } } - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); return rv; } @@ -1634,13 +1713,16 @@ void md_bitmap_end_sync(struct bitmap *b { bitmap_counter_t *bmc; unsigned long flags; + spinlock_t *bmclock; if (bitmap == NULL) { *blocks = 1024; return; } - spin_lock_irqsave(&bitmap->counts.lock, flags); - bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0); + bmclock = md_bitmap_get_bmclock(&bitmap->counts, offset); + read_lock(&bitmap->counts.mlock); + spin_lock_irqsave(bmclock, flags); + bmc = md_bitmap_get_counter(&bitmap->counts, offset, blocks, 0, bmclock, 1); if (bmc == NULL) goto unlock; /* locked */ @@ -1657,7 +1739,8 @@ void md_bitmap_end_sync(struct bitmap *b } } unlock: - spin_unlock_irqrestore(&bitmap->counts.lock, flags); + spin_unlock_irqrestore(bmclock, flags); + read_unlock(&bitmap->counts.mlock); } EXPORT_SYMBOL(md_bitmap_end_sync); @@ -1738,10 +1821,15 @@ static void md_bitmap_set_memory_bits(st sector_t secs; bitmap_counter_t *bmc; - spin_lock_irq(&bitmap->counts.lock); - bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1); + spinlock_t *bmclock; + + bmclock = md_bitmap_get_bmclock(&bitmap->counts, offset); + read_lock(&bitmap->counts.mlock); + spin_lock_irq(bmclock); + bmc = md_bitmap_get_counter(&bitmap->counts, offset, &secs, 1, bmclock, 1); if (!bmc) { - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); return; } if (!*bmc) { @@ -1752,7 +1840,8 @@ static void md_bitmap_set_memory_bits(st } if (needed) *bmc |= NEEDED_MASK; - spin_unlock_irq(&bitmap->counts.lock); + spin_unlock_irq(bmclock); + read_unlock(&bitmap->counts.mlock); } /* dirty the memory and file bits for bitmap chunks "s" to "e" */ @@ -1806,6 +1895,7 @@ void md_bitmap_free(struct bitmap *bitma { unsigned long k, pages; struct bitmap_page *bp; + spinlock_t *bmclocks; if (!bitmap) /* there was no bitmap */ return; @@ -1826,6 +1916,7 @@ void md_bitmap_free(struct bitmap *bitma bp = bitmap->counts.bp; pages = bitmap->counts.pages; + bmclocks = bitmap->counts.bmclocks; /* free all allocated memory */ @@ -1834,6 +1925,7 @@ void md_bitmap_free(struct bitmap *bitma if (bp[k].map && !bp[k].hijacked) kfree(bp[k].map); kfree(bp); + kfree(bmclocks); kfree(bitmap); } EXPORT_SYMBOL(md_bitmap_free); @@ -1900,7 +1992,9 @@ struct bitmap *md_bitmap_create(struct m if (!bitmap) return ERR_PTR(-ENOMEM); - spin_lock_init(&bitmap->counts.lock); + /* initialize metadata lock */ + rwlock_init(&bitmap->counts.mlock); + atomic_set(&bitmap->pending_writes, 0); init_waitqueue_head(&bitmap->write_wait); init_waitqueue_head(&bitmap->overflow_wait); @@ -2143,6 +2237,8 @@ int md_bitmap_resize(struct bitmap *bitm int ret = 0; long pages; struct bitmap_page *new_bp; + spinlock_t *new_bmclocks; + int num_bmclocks, i; if (bitmap->storage.file && !init) { pr_info("md: cannot resize file-based bitmap\n"); @@ -2211,7 +2307,7 @@ int md_bitmap_resize(struct bitmap *bitm memcpy(page_address(store.sb_page), page_address(bitmap->storage.sb_page), sizeof(bitmap_super_t)); - spin_lock_irq(&bitmap->counts.lock); + write_lock_irq(&bitmap->counts.mlock); md_bitmap_file_unmap(&bitmap->storage); bitmap->storage = store; @@ -2227,18 +2323,30 @@ int md_bitmap_resize(struct bitmap *bitm blocks = min(old_counts.chunks << old_counts.chunkshift, chunks << chunkshift); + /* initialize bmc locks */ + num_bmclocks = DIV_ROUND_UP(chunks, BITMAP_COUNTER_LOCK_RATIO); + pr_debug("========>>> num_bmclocks = %d, blocks = %lld\n", num_bmclocks, blocks); + + // new_bmclocks = kcalloc(num_bmclocks, sizeof(*new_bmclocks), GFP_KERNEL); + new_bmclocks = kvzalloc(num_bmclocks * sizeof(*new_bmclocks), GFP_KERNEL); + bitmap->counts.bmclocks = new_bmclocks; + for (i = 0; i < num_bmclocks; ++i) { + spinlock_t *bmclock = &(bitmap->counts.bmclocks)[i]; + // pr_debug("========>>> &bmclocks[0] = 0x%pK, i = %d, bmclock = 0x%pK\n", &bitmap->counts.bmclocks[0], i, bmclock); + spin_lock_init(bmclock); + } + /* For cluster raid, need to pre-allocate bitmap */ if (mddev_is_clustered(bitmap->mddev)) { unsigned long page; for (page = 0; page < pages; page++) { - ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1); + ret = md_bitmap_checkpage(&bitmap->counts, page, 1, 1, 0, 0); if (ret) { unsigned long k; /* deallocate the page memory */ - for (k = 0; k < page; k++) { + for (k = 0; k < page; k++) kfree(new_bp[k].map); - } kfree(new_bp); /* restore some fields from old_counts */ @@ -2261,11 +2369,11 @@ int md_bitmap_resize(struct bitmap *bitm bitmap_counter_t *bmc_old, *bmc_new; int set; - bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0); + bmc_old = md_bitmap_get_counter(&old_counts, block, &old_blocks, 0, 0, 0); set = bmc_old && NEEDED(*bmc_old); if (set) { - bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1); + bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1, 0, 0); if (bmc_new) { if (*bmc_new == 0) { /* need to set on-disk bits too. */ @@ -2301,7 +2409,7 @@ int md_bitmap_resize(struct bitmap *bitm int i; while (block < (chunks << chunkshift)) { bitmap_counter_t *bmc; - bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1); + bmc = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1, 0, 0); if (bmc) { /* new space. It needs to be resynced, so * we set NEEDED_MASK. @@ -2317,7 +2425,7 @@ int md_bitmap_resize(struct bitmap *bitm for (i = 0; i < bitmap->storage.file_pages; i++) set_page_attr(bitmap, i, BITMAP_PAGE_DIRTY); } - spin_unlock_irq(&bitmap->counts.lock); + write_unlock_irq(&bitmap->counts.mlock); if (!init) { md_bitmap_unplug(bitmap); diff -uprN origlinux-6.6.1/drivers/md/md-bitmap.h linux-6.6.1/drivers/md/md-bitmap.h --- origlinux-6.6.1/drivers/md/md-bitmap.h 2023-11-13 20:48:43.410856322 +0800 +++ linux-6.6.1/drivers/md/md-bitmap.h 2023-11-13 22:06:01.020479486 +0800 @@ -2,7 +2,9 @@ /* * bitmap.h: Copyright (C) Peter T. Breuer (ptb@xxxxxxxxxx) 2003 * - * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc. + * additions: + * Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc. + * Copyright (C) 2022-2023, Shushu Yi (firnyee@xxxxxxxxx) */ #ifndef BITMAP_H #define BITMAP_H 1 @@ -103,6 +105,9 @@ typedef __u16 bitmap_counter_t; #define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1) #define BITMAP_BLOCK_SHIFT 9 +/* how many conters share the same bmclock? */ +#define BITMAP_COUNTER_LOCK_RATIO_SHIFT 0 +#define BITMAP_COUNTER_LOCK_RATIO (1 << BITMAP_COUNTER_LOCK_RATIO_SHIFT) #endif @@ -116,7 +121,7 @@ typedef __u16 bitmap_counter_t; enum bitmap_state { BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */ BITMAP_WRITE_ERROR = 2, /* A write error has occurred */ - BITMAP_HOSTENDIAN =15, + BITMAP_HOSTENDIAN = 15, }; /* the superblock at the front of the bitmap file -- little endian */ @@ -180,7 +185,8 @@ struct bitmap_page { struct bitmap { struct bitmap_counts { - spinlock_t lock; + rwlock_t mlock; /* lock for metadata */ + spinlock_t *bmclocks; /* locks for bmc */ struct bitmap_page *bp; unsigned long pages; /* total number of pages * in the bitmap */ diff -uprN origlinux-6.6.1/drivers/md/raid5.h linux-6.6.1/drivers/md/raid5.h --- origlinux-6.6.1/drivers/md/raid5.h 2023-11-13 20:48:43.414856314 +0800 +++ linux-6.6.1/drivers/md/raid5.h 2023-11-13 21:03:11.439200413 +0800 @@ -501,7 +501,7 @@ struct disk_info { * and creating that much locking depth can cause * problems. */ -#define NR_STRIPE_HASH_LOCKS 8 +#define NR_STRIPE_HASH_LOCKS 128 #define STRIPE_HASH_LOCKS_MASK (NR_STRIPE_HASH_LOCKS - 1) struct r5worker {
