On Thu, Nov 10, 2016 at 4:06 PM, Kees Cook <[email protected]> wrote: > On Thu, Oct 20, 2016 at 12:34 AM, Joel Fernandes <[email protected]> wrote: >> 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, >> ramoops's ftrace usecase has a FTRACE_PER_CPU flag introduced in this patch >> series which splits the ftrace memory area into a single zone per CPU thus >> eliminating the need for locking. In preparation for this, make the locking >> optional. >> >> Signed-off-by: Joel Fernandes <[email protected]> >> --- >> fs/pstore/ram_core.c | 11 +++++------ >> 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 3975dee..cb92055 100644 >> --- a/fs/pstore/ram_core.c >> +++ b/fs/pstore/ram_core.c >> @@ -48,8 +48,6 @@ 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) >> { >> @@ -57,7 +55,7 @@ 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; >> @@ -65,7 +63,7 @@ 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; >> } >> @@ -77,7 +75,7 @@ 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) >> @@ -89,7 +87,7 @@ 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, >> @@ -493,6 +491,7 @@ 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 c668c86..244d242 100644 >> --- a/include/linux/pstore_ram.h >> +++ b/include/linux/pstore_ram.h >> @@ -40,6 +40,7 @@ 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; >> -- >> 2.7.4 >> > > This one looks good, thanks. I'll get this in for -next since it's a > good clean-up on its own. > Thanks.
> Have you put these patches through scripts/checkpatch.pl? Some of > lines wrap or have wide commit messages, but that's just cosmetic to > fix up. I didn't have any errors, just 1 or 2 warnings about wide commit messages yes. I'll fix those up on the other patches you commented on and resend them, thanks! Regards, Joel
