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authorMinchan Kim <minchan@kernel.org>2022-01-22 09:14:10 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-22 09:33:37 +0300
commit4a57d6bbaecd28c8175dc5da013009e4158018c2 (patch)
treee69e2936a8292fa1d0fdd19794e50bf3dd0a3e3a /include/linux/rwlock.h
parentc4549b871102db01ba23cce4bd0cdac511f8991d (diff)
downloadlinux-4a57d6bbaecd28c8175dc5da013009e4158018c2.tar.xz
locking/rwlocks: introduce write_lock_nested
In preparation for converting bit_spin_lock to rwlock in zsmalloc so that multiple writers of zspages can run at the same time but those zspages are supposed to be different zspage instance. Thus, it's not deadlock. This patch adds write_lock_nested to support the case for LOCKDEP. [minchan@kernel.org: fix write_lock_nested for RT] Link: https://lkml.kernel.org/r/YZfrMTAXV56HFWJY@google.com [bigeasy@linutronix.de: fixup write_lock_nested() implementation] Link: https://lkml.kernel.org/r/20211123170134.y6xb7pmpgdn4m3bn@linutronix.de Link: https://lkml.kernel.org/r/20211115185909.3949505-8-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/rwlock.h')
-rw-r--r--include/linux/rwlock.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/rwlock.h b/include/linux/rwlock.h
index 2c0ad417ce3c..8f416c5e929e 100644
--- a/include/linux/rwlock.h
+++ b/include/linux/rwlock.h
@@ -55,6 +55,12 @@ do { \
#define write_lock(lock) _raw_write_lock(lock)
#define read_lock(lock) _raw_read_lock(lock)
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+#define write_lock_nested(lock, subclass) _raw_write_lock_nested(lock, subclass)
+#else
+#define write_lock_nested(lock, subclass) _raw_write_lock(lock)
+#endif
+
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
#define read_lock_irqsave(lock, flags) \