diff options
| author | Joel Fernandes <joelaf@google.com> | 2016-10-20 00:34:00 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-06 19:19:38 -0700 |
| commit | 08408f7ae5cdc7b8ef439f29b8d3dff9f1389c25 (patch) | |
| tree | 66588b5d1126fa864d3cb0da684c76d7fb803370 /fs/pstore | |
| parent | b627f60019489332a47ae9028c4891b4ed563f23 (diff) | |
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>
Diffstat (limited to 'fs/pstore')
| -rw-r--r-- | fs/pstore/ram_core.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index 364d2dffe5a6..2556ec00dbab 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -47,8 +47,6 @@ static inline size_t buffer_start(struct persistent_ram_zone *prz) return atomic_read(&prz->buffer->start); } -static DEFINE_RAW_SPINLOCK(buffer_lock); - /* increase and wrap the start pointer, returning the old value */ static size_t buffer_start_add(struct persistent_ram_zone *prz, size_t a) { @@ -56,7 +54,7 @@ static size_t buffer_start_add(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; @@ -64,7 +62,7 @@ static size_t buffer_start_add(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; } @@ -76,7 +74,7 @@ static void buffer_size_add(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) @@ -88,7 +86,7 @@ static void buffer_size_add(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 void notrace persistent_ram_encode_rs8(struct persistent_ram_zone *prz, @@ -450,6 +448,7 @@ 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; } |