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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/zram-Replace-bit-spinlocks-with-spinlock_t-for-PREEM.patch | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/debian/patches-rt/zram-Replace-bit-spinlocks-with-spinlock_t-for-PREEM.patch b/debian/patches-rt/zram-Replace-bit-spinlocks-with-spinlock_t-for-PREEM.patch new file mode 100644 index 000000000..0ccb2d87c --- /dev/null +++ b/debian/patches-rt/zram-Replace-bit-spinlocks-with-spinlock_t-for-PREEM.patch @@ -0,0 +1,94 @@ +From: Mike Galbraith <umgwanakikbuti@gmail.com> +Date: Thu, 31 Mar 2016 04:08:28 +0200 +Subject: [PATCH] zram: Replace bit spinlocks with spinlock_t for PREEMPT_RT. +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +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. + +Use a spinlock_t on PREEMPT_RT for locking and set/ clear ZRAM_LOCK bit after +the lock has been acquired/ dropped. + +Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Link: https://lkml.kernel.org/r/YqIbMuHCPiQk+Ac2@linutronix.de +Link: https://lore.kernel.org/20230323161830.jFbWCosd@linutronix.de +--- + drivers/block/zram/zram_drv.c | 37 +++++++++++++++++++++++++++++++++++++ + drivers/block/zram/zram_drv.h | 3 +++ + 2 files changed, 40 insertions(+) + +--- a/drivers/block/zram/zram_drv.c ++++ b/drivers/block/zram/zram_drv.c +@@ -57,6 +57,41 @@ static void zram_free_page(struct zram * + static int zram_read_page(struct zram *zram, struct page *page, u32 index, + struct bio *parent); + ++#ifdef CONFIG_PREEMPT_RT ++static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) ++{ ++ size_t index; ++ ++ for (index = 0; index < num_pages; index++) ++ spin_lock_init(&zram->table[index].lock); ++} ++ ++static int zram_slot_trylock(struct zram *zram, u32 index) ++{ ++ 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) ++{ ++ spin_lock(&zram->table[index].lock); ++ __set_bit(ZRAM_LOCK, &zram->table[index].flags); ++} ++ ++static void zram_slot_unlock(struct zram *zram, u32 index) ++{ ++ __clear_bit(ZRAM_LOCK, &zram->table[index].flags); ++ spin_unlock(&zram->table[index].lock); ++} ++ ++#else ++ ++static void zram_meta_init_table_locks(struct zram *zram, size_t num_pages) { } ++ + static int zram_slot_trylock(struct zram *zram, u32 index) + { + return bit_spin_trylock(ZRAM_LOCK, &zram->table[index].flags); +@@ -71,6 +106,7 @@ static void zram_slot_unlock(struct zram + { + bit_spin_unlock(ZRAM_LOCK, &zram->table[index].flags); + } ++#endif + + static inline bool init_done(struct zram *zram) + { +@@ -1245,6 +1281,7 @@ static bool zram_meta_alloc(struct zram + + if (!huge_class_size) + huge_class_size = zs_huge_class_size(zram->mem_pool); ++ zram_meta_init_table_locks(zram, num_pages); + return true; + } + +--- a/drivers/block/zram/zram_drv.h ++++ b/drivers/block/zram/zram_drv.h +@@ -69,6 +69,9 @@ struct zram_table_entry { + unsigned long element; + }; + unsigned long flags; ++#ifdef CONFIG_PREEMPT_RT ++ spinlock_t lock; ++#endif + #ifdef CONFIG_ZRAM_MEMORY_TRACKING + ktime_t ac_time; + #endif |