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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:38 +0000
commit08b74a000942a380fe028845f92cd3a0dee827d5 (patch)
treeaa78b4e12607c3e1fcce8d5cc42df4330792f118 /debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch
parentAdding upstream version 4.19.249. (diff)
downloadlinux-08b74a000942a380fe028845f92cd3a0dee827d5.tar.xz
linux-08b74a000942a380fe028845f92cd3a0dee827d5.zip
Adding debian version 4.19.249-2.debian/4.19.249-2debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch')
-rw-r--r--debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch104
1 files changed, 104 insertions, 0 deletions
diff --git a/debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch b/debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch
new file mode 100644
index 000000000..04dcb13d9
--- /dev/null
+++ b/debian/patches-rt/0246-drivers-block-zram-Replace-bit-spinlocks-with-rtmute.patch
@@ -0,0 +1,104 @@
+From cdff10ec863d6d0e7d18beb8cb66adc86674bb2b Mon Sep 17 00:00:00 2001
+From: Mike Galbraith <umgwanakikbuti@gmail.com>
+Date: Thu, 31 Mar 2016 04:08:28 +0200
+Subject: [PATCH 246/347] drivers/block/zram: Replace bit spinlocks with
+ rtmutex for -rt
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.19/older/patches-4.19.246-rt110.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 | 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
+--
+2.36.1
+