diff options
Diffstat (limited to 'debian/patches-rt/0245-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch')
| -rw-r--r-- | debian/patches-rt/0245-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/debian/patches-rt/0245-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch b/debian/patches-rt/0245-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch new file mode 100644 index 000000000..b33d8a7a0 --- /dev/null +++ b/debian/patches-rt/0245-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch @@ -0,0 +1,100 @@ +From: Mike Galbraith <umgwanakikbuti@gmail.com> +Date: Thu, 31 Mar 2016 04:08:28 +0200 +Subject: [PATCH 245/342] drivers/block/zram: Replace bit spinlocks with + rtmutex for -rt +Origin: https://git.kernel.org/cgit/linux/kernel/git/rt/linux-stable-rt.git/commit?id=e9c40001860ea506bbb2d75c4f9a704fdce8b98c + +They're nondeterministic, and lead to ___might_sleep() splats in -rt. +OTOH, they're a lot less wasteful than an rtmutex per page. + +Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/block/zram/zram_drv.c | 38 +++++++++++++++++++++++++++++++++++ + drivers/block/zram/zram_drv.h | 3 +++ + 2 files changed, 41 insertions(+) + +diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c +index 5e05bfcecd7b..04e4297f8318 100644 +--- a/drivers/block/zram/zram_drv.c ++++ b/drivers/block/zram/zram_drv.c +@@ -53,6 +53,40 @@ static size_t huge_class_size; + + static void zram_free_page(struct zram *zram, size_t index); + ++#ifdef CONFIG_PREEMPT_RT_BASE ++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].value); ++ 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].value); ++} ++ ++static void zram_slot_unlock(struct zram *zram, u32 index) ++{ ++ __clear_bit(ZRAM_LOCK, &zram->table[index].value); ++ 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].value); +@@ -67,6 +101,7 @@ static void zram_slot_unlock(struct zram *zram, u32 index) + { + bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value); + } ++#endif + + static inline bool init_done(struct zram *zram) + { +@@ -902,6 +937,8 @@ static DEVICE_ATTR_RO(io_stat); + static DEVICE_ATTR_RO(mm_stat); + static DEVICE_ATTR_RO(debug_stat); + ++ ++ + static void zram_meta_free(struct zram *zram, u64 disksize) + { + size_t num_pages = disksize >> PAGE_SHIFT; +@@ -932,6 +969,7 @@ static bool zram_meta_alloc(struct zram *zram, u64 disksize) + + if (!huge_class_size) + huge_class_size = zs_huge_class_size(zram->mem_pool); ++ zram_meta_init_table_locks(zram, num_pages); + return true; + } + +diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h +index d1095dfdffa8..144e91061df8 100644 +--- a/drivers/block/zram/zram_drv.h ++++ b/drivers/block/zram/zram_drv.h +@@ -61,6 +61,9 @@ struct zram_table_entry { + unsigned long element; + }; + unsigned long value; ++#ifdef CONFIG_PREEMPT_RT_BASE ++ spinlock_t lock; ++#endif + #ifdef CONFIG_ZRAM_MEMORY_TRACKING + ktime_t ac_time; + #endif |