Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1470510 > unrolled thread
| Started by | John Stultz <john.stultz@linaro.org> |
|---|---|
| First post | 2016-08-26 04:30 +0200 |
| Last post | 2016-08-26 22:20 +0200 |
| Articles | 4 — 4 participants |
Back to article view | Back to linux.kernel
This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by
below is the oldest one visible, not the original post.
Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact John Stultz <john.stultz@linaro.org> - 2016-08-26 04:30 +0200
Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact Tejun Heo <tj@kernel.org> - 2016-08-26 15:00 +0200
Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact Dmitry Shmidt <dimitrysh@google.com> - 2016-08-26 18:50 +0200
Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact Om Dhyade <odhyade@codeaurora.org> - 2016-08-26 22:20 +0200
| From | John Stultz <john.stultz@linaro.org> |
|---|---|
| Date | 2016-08-26 04:30 +0200 |
| Subject | Re: [PATCH v2] locking/percpu-rwsem: Optimize readers and reduce global impact |
| Message-ID | <saf45-Zl-5@gated-at.bofh.it> |
On Wed, Aug 24, 2016 at 2:30 PM, Tejun Heo <tj@kernel.org> wrote: > Hello, John. > > On Wed, Aug 24, 2016 at 02:16:52PM -0700, John Stultz wrote: >> Hey Peter, Tejun, Oleg, >> So while you're tweaks for the percpu-rwsem have greatly helped the >> regression folks were seeing (many thanks, by the way), as noted >> above, the performance regression with the global lock compared to >> earlier kernels is still ~3x slower (though again, much better then >> the 80x slower that was seen earlier). >> >> So I was wondering if patches to go back to the per signal_struct >> locking would still be considered? Or is the global lock approach the >> only way forward? > > We can't simply revert but we can make the lock per signal_struct > again. It's just that it'd be quite a bit more complex (but, again, > if we need it...) and for cases where migrations aren't as frequent > percpu-rwsem would be at least a bit lower overhead. Can you please > test with the following patch applied just in case? > > https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/commit/?h=for-4.8-fixes&id=568ac888215c7fb2fabe8ea739b00ec3c1f5d440 Hey! Good news. This patch along with Peter's locking changes pushes the latencies down to an apparently acceptable level! Many thanks for the pointer! thanks -john
[toc] | [next] | [standalone]
| From | Tejun Heo <tj@kernel.org> |
|---|---|
| Date | 2016-08-26 15:00 +0200 |
| Message-ID | <saoTL-7aM-25@gated-at.bofh.it> |
| In reply to | #1470510 |
Hello, John. On Thu, Aug 25, 2016 at 07:14:07PM -0700, John Stultz wrote: > Hey! Good news. This patch along with Peter's locking changes pushes > the latencies down to an apparently acceptable level! Ah, that's good to hear. Please feel free to ping me if you guys wanna talk about cgroup usage in android. Thanks! -- tejun
[toc] | [prev] | [next] | [standalone]
| From | Dmitry Shmidt <dimitrysh@google.com> |
|---|---|
| Date | 2016-08-26 18:50 +0200 |
| Message-ID | <sasum-18E-29@gated-at.bofh.it> |
| In reply to | #1470697 |
On Fri, Aug 26, 2016 at 5:51 AM, Tejun Heo <tj@kernel.org> wrote: > Hello, John. > > On Thu, Aug 25, 2016 at 07:14:07PM -0700, John Stultz wrote: >> Hey! Good news. This patch along with Peter's locking changes pushes >> the latencies down to an apparently acceptable level! > > Ah, that's good to hear. Please feel free to ping me if you guys > wanna talk about cgroup usage in android. Thanks a lot for all your help resolving this issue! > Thanks! > > -- > tejun
[toc] | [prev] | [next] | [standalone]
| From | Om Dhyade <odhyade@codeaurora.org> |
|---|---|
| Date | 2016-08-26 22:20 +0200 |
| Message-ID | <savLA-3ml-13@gated-at.bofh.it> |
| In reply to | #1470891 |
On 8/26/2016 9:47 AM, Dmitry Shmidt wrote: > On Fri, Aug 26, 2016 at 5:51 AM, Tejun Heo <tj@kernel.org> wrote: >> Hello, John. >> >> On Thu, Aug 25, 2016 at 07:14:07PM -0700, John Stultz wrote: >>> Hey! Good news. This patch along with Peter's locking changes pushes >>> the latencies down to an apparently acceptable level! >> >> Ah, that's good to hear. Please feel free to ping me if you guys >> wanna talk about cgroup usage in android. > > Thanks a lot for all your help resolving this issue! > Thank you for the help. >> Thanks! >> >> -- >> tejun -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
[toc] | [prev] | [standalone]
Back to top | Article view | linux.kernel
csiph-web