84 lines
2.8 KiB
Diff
84 lines
2.8 KiB
Diff
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From: Mike Galbraith <umgwanakikbuti@gmail.com>
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Date: Thu, 31 Mar 2016 04:08:28 +0200
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Subject: [PATCH 1/3] zram: Replace bit spinlocks with a spinlock_t.
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.11/older/patches-6.11-rt7.tar.xz
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The bit spinlock disables preemption. The spinlock_t lock becomes a sleeping
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lock on PREEMPT_RT and it can not be acquired in this context. In this locked
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section, zs_free() acquires a zs_pool::lock, and there is access to
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zram::wb_limit_lock.
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Add a spinlock_t for locking. Keep the set/ clear ZRAM_LOCK bit after
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the lock has been acquired/ dropped. The size of struct zram_table_entry
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increases by 4 bytes due to lock and additional 4 bytes padding with
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CONFIG_ZRAM_TRACK_ENTRY_ACTIME enabled.
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Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
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Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Link: https://lore.kernel.org/20240906141520.730009-2-bigeasy@linutronix.de
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---
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drivers/block/zram/zram_drv.c | 18 ++++++++++++++----
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drivers/block/zram/zram_drv.h | 1 +
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2 files changed, 15 insertions(+), 4 deletions(-)
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--- a/drivers/block/zram/zram_drv.c
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+++ b/drivers/block/zram/zram_drv.c
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@@ -59,17 +59,24 @@ static int zram_read_page(struct zram *z
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static int zram_slot_trylock(struct zram *zram, u32 index)
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{
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- return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags);
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+ int ret;
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+
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+ ret = spin_trylock(&zram->table[index].lock);
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+ if (ret)
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+ __set_bit(ZRAM_LOCK, &zram->table[index].flags);
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+ return ret;
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}
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static void zram_slot_lock(struct zram *zram, u32 index)
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{
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- bit_spin_lock(ZRAM_LOCK, &zram->table[index].flags);
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+ spin_lock(&zram->table[index].lock);
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+ __set_bit(ZRAM_LOCK, &zram->table[index].flags);
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}
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static void zram_slot_unlock(struct zram *zram, u32 index)
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{
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- bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags);
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+ __clear_bit(ZRAM_LOCK, &zram->table[index].flags);
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+ spin_unlock(&zram->table[index].lock);
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}
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static inline bool init_done(struct zram *zram)
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@@ -1211,7 +1218,7 @@ static void zram_meta_free(struct zram *
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static bool zram_meta_alloc(struct zram *zram, u64 disksize)
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{
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- size_t num_pages;
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+ size_t num_pages, index;
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num_pages = disksize >> PAGE_SHIFT;
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zram->table = vzalloc(array_size(num_pages, sizeof(*zram->table)));
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@@ -1226,6 +1233,9 @@ static bool zram_meta_alloc(struct zram
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if (!huge_class_size)
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huge_class_size = zs_huge_class_size(zram->mem_pool);
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+
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+ for (index = 0; index < num_pages; index++)
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+ spin_lock_init(&zram->table[index].lock);
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return true;
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}
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--- a/drivers/block/zram/zram_drv.h
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+++ b/drivers/block/zram/zram_drv.h
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@@ -69,6 +69,7 @@ struct zram_table_entry {
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unsigned long element;
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};
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unsigned long flags;
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+ spinlock_t lock;
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#ifdef CONFIG_ZRAM_TRACK_ENTRY_ACTIME
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ktime_t ac_time;
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#endif
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