87 lines
2.5 KiB
Diff
87 lines
2.5 KiB
Diff
From: Mike Galbraith <umgwanakikbuti@gmail.com>
|
|
Date: Thu, 31 Mar 2016 04:08:28 +0200
|
|
Subject: [PATCH] drivers/block/zram: Replace bit spinlocks with rtmutex
|
|
for -rt
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.18/older/patches-4.18.7-rt5.tar.xz
|
|
|
|
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 | 28 ++++++++++++++++++++++++++++
|
|
drivers/block/zram/zram_drv.h | 3 +++
|
|
2 files changed, 31 insertions(+)
|
|
|
|
--- a/drivers/block/zram/zram_drv.c
|
|
+++ b/drivers/block/zram/zram_drv.c
|
|
@@ -53,6 +53,30 @@ 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 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 void zram_slot_lock(struct zram *zram, u32 index)
|
|
{
|
|
bit_spin_lock(ZRAM_LOCK, &zram->table[index].value);
|
|
@@ -62,6 +86,7 @@ static void zram_slot_unlock(struct zram
|
|
{
|
|
bit_spin_unlock(ZRAM_LOCK, &zram->table[index].value);
|
|
}
|
|
+#endif
|
|
|
|
static inline bool init_done(struct zram *zram)
|
|
{
|
|
@@ -898,6 +923,8 @@ 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;
|
|
@@ -928,6 +955,7 @@ 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
|
|
@@ -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
|