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| author | Joel Fernandes <joelaf@google.com> | 2016-10-20 00:34:00 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-11 09:30:08 -0700 |
| commit | 2d0abb7b0debd522a0752571be1e820f45333d83 (patch) | |
| tree | 21c74a438f0cea37e319169d559be8fc5ff1aee6 | |
| parent | c64a196b2b667555af9231dae4e63af6590ed2c7 (diff) | |
| download | linux-stable-2d0abb7b0debd522a0752571be1e820f45333d83.tar.gz linux-stable-2d0abb7b0debd522a0752571be1e820f45333d83.tar.bz2 linux-stable-2d0abb7b0debd522a0752571be1e820f45333d83.zip | |
pstore: Make spinlock per zone instead of global
commit 109704492ef637956265ec2eb72ae7b3b39eb6f4 upstream.
Currently pstore has a global spinlock for all zones. Since the zones
are independent and modify different areas of memory, there's no need
to have a global lock, so we should use a per-zone lock as introduced
here. Also, when ramoops's ftrace use-case has a FTRACE_PER_CPU flag
introduced later, which splits the ftrace memory area into a single zone
per CPU, it will eliminate the need for locking. In preparation for this,
make the locking optional.
Signed-off-by: Joel Fernandes <joelaf@google.com>
[kees: updated commit message]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/pstore/ram_core.c | 11 | ||||
| -rw-r--r-- | include/linux/pstore_ram.h | 1 |
2 files changed, 6 insertions, 6 deletions
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 76c3f80efdfa..feb8d7bfab09 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -80,8 +80,6 @@ static void buffer_size_add_atomic(struct persistent_ram_zone *prz, size_t a) } while (atomic_cmpxchg(&prz->buffer->size, old, new) != old); } -static DEFINE_RAW_SPINLOCK(buffer_lock); - /* increase and wrap the start pointer, returning the old value */ static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a) { @@ -89,7 +87,7 @@ static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a) int new; unsigned long flags; - raw_spin_lock_irqsave(&buffer_lock, flags); + raw_spin_lock_irqsave(&prz->buffer_lock, flags); old = atomic_read(&prz->buffer->start); new = old + a; @@ -97,7 +95,7 @@ static size_t buffer_start_add_locked(struct persistent_ram_zone *prz, size_t a) new -= prz->buffer_size; atomic_set(&prz->buffer->start, new); - raw_spin_unlock_irqrestore(&buffer_lock, flags); + raw_spin_unlock_irqrestore(&prz->buffer_lock, flags); return old; } @@ -109,7 +107,7 @@ static void buffer_size_add_locked(struct persistent_ram_zone *prz, size_t a) size_t new; unsigned long flags; - raw_spin_lock_irqsave(&buffer_lock, flags); + raw_spin_lock_irqsave(&prz->buffer_lock, flags); old = atomic_read(&prz->buffer->size); if (old == prz->buffer_size) @@ -121,7 +119,7 @@ static void buffer_size_add_locked(struct persistent_ram_zone *prz, size_t a) atomic_set(&prz->buffer->size, new); exit: - raw_spin_unlock_irqrestore(&buffer_lock, flags); + raw_spin_unlock_irqrestore(&prz->buffer_lock, flags); } static size_t (*buffer_start_add)(struct persistent_ram_zone *, size_t) = buffer_start_add_atomic; @@ -489,6 +487,7 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig, prz->buffer->sig = sig; persistent_ram_zap(prz); + prz->buffer_lock = __RAW_SPIN_LOCK_UNLOCKED(buffer_lock); return 0; } diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index 4af3fdc85b01..4bfcd43eb55a 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h @@ -39,6 +39,7 @@ struct persistent_ram_zone { void *vaddr; struct persistent_ram_buffer *buffer; size_t buffer_size; + raw_spinlock_t buffer_lock; /* ECC correction */ char *par_buffer; |