Thanks Shushu! Apprecaite the continued follow-ups for sure. Wrt the performance claims below can you provide the full details on test setup and results? Within the next few days I should have a chance to run this again on latest Xeon with gen5 Samsungs. -Paul On Tue, 16 Apr 2024 13:22:53 +0800 Shushu Yi <teddyxym@xxxxxxxxxxx> wrote: > Optimize scattered address space. Achieves significant improvements in > both throughput and latency. > > Maximize thread-level parallelism and reduce CPU suspension time > caused by lock contention. Achieve increased overall storage > throughput by 89.4% and decrease the 99.99th percentile I/O latency > by 85.4% on a system with four PCIe 4.0 SSDs. > > Note: Publish this work as a paper and provide the URL > (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> > Tested-by: Paul Luse <paul.e.luse@xxxxxxxxx> > --- > V1 -> V2: Cleaned up coding style and divided into 2 patches (HemiRAID > and ScalaRAID corresponding to the paper mentioned above). ScalaRAID > equipped every counter with a counter lock and employ our D-Block. > HemiRAID increased the number of stripe locks to 128 > V2 -> V3: Adjusted the language used in the subject and changelog. > Since patch 1/2 in V2 cannot be used independently and does not > encompass all of our work, it has been merged into a single patch. > V3 -> V4: Fixed incorrect sending address and changelog format. > > drivers/md/md-bitmap.c | 197 > ++++++++++++++++++++++++++++++----------- drivers/md/md-bitmap.h | > 12 ++- 2 files changed, 154 insertions(+), 55 deletions(-) > > diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c > index 059afc24c08b..5ed5fe810b2f 100644 > --- a/drivers/md/md-bitmap.c > +++ b/drivers/md/md-bitmap.c > @@ -47,10 +47,12 @@ static inline char *bmname(struct bitmap *bitmap) > * if we find our page, we increment the page's refcount so that it > stays > * 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) > +static int md_bitmap_checkpage(struct bitmap_counts *bitmap, > 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"); @@ -399,7 +407,7 @@ static int read_file_page(struct > file *file, unsigned long index, } > > 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: > @@ -458,7 +466,7 @@ static void md_bitmap_wait_writes(struct bitmap > *bitmap) { > 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 > @@ -1248,16 +1256,28 @@ void md_bitmap_write_all(struct bitmap > *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; > + > 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; > + > struct bitmap_page *bp = &bitmap->bp[page]; > > if (!bp->pending) > @@ -1266,7 +1286,7 @@ static void md_bitmap_set_pending(struct > bitmap_counts *bitmap, sector_t offset) > 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 +1369,7 @@ void md_bitmap_daemon_work(struct mddev *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 +1384,7 @@ void md_bitmap_daemon_work(struct mddev *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 +1400,7 @@ void md_bitmap_daemon_work(struct mddev *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 +1433,25 @@ void md_bitmap_daemon_work(struct > mddev *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 csize; > int err; > > @@ -1435,7 +1463,7 @@ __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 +1489,28 @@ __acquires(bitmap->lock) > &(bitmap->bp[page].map[pageoff]); > } > > +/* set-association */ > +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; > + > + spinlock_t *bmclock = &(bitmap->bmclocks[lockid]); > + return bmclock; > +} > + > int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, > unsigned long sectors, int behind) { > if (!bitmap) > @@ -1480,11 +1530,15 @@ int md_bitmap_startwrite(struct bitmap > *bitmap, sector_t offset, unsigned long s 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 +1550,8 @@ int md_bitmap_startwrite(struct bitmap *bitmap, > sector_t offset, unsigned long s */ > 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 +1568,8 @@ int md_bitmap_startwrite(struct bitmap *bitmap, > sector_t offset, unsigned long s > (*bmc)++; > > - spin_unlock_irq(&bitmap->counts.lock); > + spin_unlock_irq(bmclock); > + read_unlock(&bitmap->counts.mlock); > > offset += blocks; > if (sectors > blocks) > @@ -1542,11 +1598,15 @@ void md_bitmap_endwrite(struct bitmap > *bitmap, sector_t offset, 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 +1628,8 @@ void md_bitmap_endwrite(struct bitmap *bitmap, > sector_t offset, 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 +1643,16 @@ static int __bitmap_start_sync(struct bitmap > *bitmap, sector_t offset, sector_t 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 +1666,8 @@ static int __bitmap_start_sync(struct bitmap > *bitmap, sector_t offset, sector_t } > } > } > - spin_unlock_irq(&bitmap->counts.lock); > + spin_unlock_irq(bmclock); > + read_unlock(&bitmap->counts.mlock); > return rv; > } > > @@ -1634,13 +1699,16 @@ void md_bitmap_end_sync(struct bitmap > *bitmap, sector_t offset, sector_t *blocks { > 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 +1725,8 @@ void md_bitmap_end_sync(struct bitmap *bitmap, > sector_t offset, sector_t *blocks } > } > 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 +1807,15 @@ static void md_bitmap_set_memory_bits(struct > bitmap *bitmap, sector_t offset, in > 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 +1826,8 @@ static void md_bitmap_set_memory_bits(struct > bitmap *bitmap, sector_t offset, in } > 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 +1881,7 @@ void md_bitmap_free(struct bitmap *bitmap) > { > unsigned long k, pages; > struct bitmap_page *bp; > + spinlock_t *bmclocks; > > if (!bitmap) /* there was no bitmap */ > return; > @@ -1826,6 +1902,7 @@ void md_bitmap_free(struct bitmap *bitmap) > > bp = bitmap->counts.bp; > pages = bitmap->counts.pages; > + bmclocks = bitmap->counts.bmclocks; > > /* free all allocated memory */ > > @@ -1834,6 +1911,7 @@ void md_bitmap_free(struct bitmap *bitmap) > if (bp[k].map && !bp[k].hijacked) > kfree(bp[k].map); > kfree(bp); > + kfree(bmclocks); > kfree(bitmap); > } > EXPORT_SYMBOL(md_bitmap_free); > @@ -1900,7 +1978,9 @@ struct bitmap *md_bitmap_create(struct mddev > *mddev, int slot) 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 +2223,8 @@ int md_bitmap_resize(struct bitmap *bitmap, > sector_t blocks, 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 +2293,7 @@ int md_bitmap_resize(struct bitmap *bitmap, > sector_t blocks, 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 +2309,28 @@ int md_bitmap_resize(struct bitmap *bitmap, > sector_t blocks, blocks = min(old_counts.chunks << > old_counts.chunkshift, chunks << chunkshift); > > + /* initialize bmc locks */ > + num_bmclocks = DIV_ROUND_UP(chunks, > BITMAP_COUNTER_LOCK_RATIO); + > + new_bmclocks = kvcalloc(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]; > + > + 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 +2353,12 @@ int md_bitmap_resize(struct > bitmap *bitmap, sector_t blocks, 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 +2394,7 @@ int md_bitmap_resize(struct bitmap > *bitmap, sector_t blocks, 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 +2410,7 @@ int md_bitmap_resize(struct bitmap *bitmap, > sector_t blocks, 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 --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h > index bb9eb418780a..1b9c36bb73ed 100644 > --- a/drivers/md/md-bitmap.h > +++ b/drivers/md/md-bitmap.h > @@ -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 counters 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 */
