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| author | Mike Galbraith <umgwanakikbuti@gmail.com> | 2024-09-06 16:14:43 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-09-06 08:51:08 -0600 |
| commit | 9518e5bfaae19447d657983d0628062ab6712610 (patch) | |
| tree | 753e393d436841da8c595f6356859ecd09901217 /drivers/block | |
| parent | 296dbc72d29085d5fc34430d0760423071e9e81d (diff) | |
| download | lwn-9518e5bfaae19447d657983d0628062ab6712610.tar.gz lwn-9518e5bfaae19447d657983d0628062ab6712610.zip | |
zram: Replace bit spinlocks with a spinlock_t.
The bit spinlock disables preemption. The spinlock_t lock becomes a sleeping
lock on PREEMPT_RT and it can not be acquired in this context. In this locked
section, zs_free() acquires a zs_pool::lock, and there is access to
zram::wb_limit_lock.
Add a spinlock_t for locking. Keep the set/ clear ZRAM_LOCK bit after
the lock has been acquired/ dropped. The size of struct zram_table_entry
increases by 4 bytes due to lock and additional 4 bytes padding with
CONFIG_ZRAM_TRACK_ENTRY_ACTIME enabled.
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/r/20240906141520.730009-2-bigeasy@linutronix.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 18 | ||||
| -rw-r--r-- | drivers/block/zram/zram_drv.h | 1 |
2 files changed, 15 insertions, 4 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index efcb8d9d274c..c1f0f2da1ec3 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -59,17 +59,24 @@ static int zram_read_page(struct zram *zram, struct page *page, u32 index, static int zram_slot_trylock(struct zram *zram, u32 index) { - return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags); + int ret; + + ret = spin_trylock(&zram->table[index].lock); + if (ret) + __set_bit(ZRAM_LOCK, &zram->table[index].flags); + return ret; } static void zram_slot_lock(struct zram *zram, u32 index) { - bit_spin_lock(ZRAM_LOCK, &zram->table[index].flags); + spin_lock(&zram->table[index].lock); + __set_bit(ZRAM_LOCK, &zram->table[index].flags); } static void zram_slot_unlock(struct zram *zram, u32 index) { - bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags); + __clear_bit(ZRAM_LOCK, &zram->table[index].flags); + spin_unlock(&zram->table[index].lock); } static inline bool init_done(struct zram *zram) @@ -1211,7 +1218,7 @@ static void zram_meta_free(struct zram *zram, u64 disksize) static bool zram_meta_alloc(struct zram *zram, u64 disksize) { - size_t num_pages; + size_t num_pages, index; num_pages = disksize >> PAGE_SHIFT; zram->table = vzalloc(array_size(num_pages, sizeof(*zram->table))); @@ -1226,6 +1233,9 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) if (!huge_class_size) huge_class_size = zs_huge_class_size(zram->mem_pool); + + for (index = 0; index < num_pages; index++) + spin_lock_init(&zram->table[index].lock); return true; } diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 35e322144629..dcc3c106ce71 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -69,6 +69,7 @@ struct zram_table_entry { unsigned long element; }; unsigned long flags; + spinlock_t lock; #ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME ktime_t ac_time; #endif |