Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-11 Thread Shaohua Li
On Tue, May 10, 2016 at 01:46:13PM +0800, Simon Guo wrote: > Hi, > On Mon, May 09, 2016 at 05:22:15PM -0700, Shaohua Li wrote: > > if trace isn't enabled, parsing cgroup path just wastes cpu > > > > Signed-off-by: Shaohua Li > > --- > > block/blk-throttle.c | 5 ++--- > > include/linux/

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-11 Thread Shaohua Li
On Wed, May 11, 2016 at 09:41:20AM -0400, Jeff Moyer wrote: > Shaohua Li writes: > > > On Tue, May 10, 2016 at 11:52:15AM -0400, Jeff Moyer wrote: > >> Shaohua Li writes: > >> > >> > if trace isn't enabled, parsing cgroup path just wastes cpu > >> > > >> > Signed-off-by: Shaohua Li > >> > ---

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-11 Thread Jeff Moyer
Steven Rostedt writes: >> Do we want to return !!(bt->act_mask & BLK_TC_NOTIFY)? > > The return type is bool. I would think that gcc would be smart enough > to make the conversion. > > To check, I compiled the following function: > > bool testbool(int x) > { > return x & 1<<3; > } > > and

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-11 Thread Jeff Moyer
Shaohua Li writes: > On Tue, May 10, 2016 at 11:52:15AM -0400, Jeff Moyer wrote: >> Shaohua Li writes: >> >> > if trace isn't enabled, parsing cgroup path just wastes cpu >> > >> > Signed-off-by: Shaohua Li >> > --- >> > block/blk-throttle.c | 5 ++--- >> > include/linux/blktrace_api.

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-11 Thread Simon Guo
Hi, On Mon, May 09, 2016 at 05:22:15PM -0700, Shaohua Li wrote: > if trace isn't enabled, parsing cgroup path just wastes cpu > > Signed-off-by: Shaohua Li > --- > block/blk-throttle.c | 5 ++--- > include/linux/blktrace_api.h | 9 + > 2 files changed, 11 insertions(+), 3 deleti

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-10 Thread Shaohua Li
On Tue, May 10, 2016 at 11:52:15AM -0400, Jeff Moyer wrote: > Shaohua Li writes: > > > if trace isn't enabled, parsing cgroup path just wastes cpu > > > > Signed-off-by: Shaohua Li > > --- > > block/blk-throttle.c | 5 ++--- > > include/linux/blktrace_api.h | 9 + > > 2 files ch

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-10 Thread Steven Rostedt
On Tue, 10 May 2016 11:52:15 -0400 Jeff Moyer wrote: > > +static inline bool blk_trace_note_message_enabled(struct request_queue *q) > > +{ > > + struct blk_trace *bt = q->blk_trace; > > + if (likely(!bt)) > > + return false; > > + return bt->act_mask & BLK_TC_NOTIFY; > > Do

Re: [PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-10 Thread Jeff Moyer
Shaohua Li writes: > if trace isn't enabled, parsing cgroup path just wastes cpu > > Signed-off-by: Shaohua Li > --- > block/blk-throttle.c | 5 ++--- > include/linux/blktrace_api.h | 9 + > 2 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/block/blk-throttle.c

[PATCH 3/3] blk-throttle: don't parse cgroup path if trace isn't enabled

2016-05-09 Thread Shaohua Li
if trace isn't enabled, parsing cgroup path just wastes cpu Signed-off-by: Shaohua Li --- block/blk-throttle.c | 5 ++--- include/linux/blktrace_api.h | 9 + 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 2149a1d.