Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-10 Thread Joel Fernandes
On Mon, Oct 10, 2016 at 10:06 PM, Joel Fernandes wrote: > On Sun, Oct 9, 2016 at 12:26 PM, Chris Wilson > wrote: >> On Sun, Oct 09, 2016 at 12:00:31PM -0700, Joel Fernandes wrote: >>> Ok. So I'll submit a patch with mutex for purge_lock and use >>> cond_resched_lock for the vmap_area_lock as you

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-10 Thread Joel Fernandes
On Sun, Oct 9, 2016 at 12:26 PM, Chris Wilson wrote: > On Sun, Oct 09, 2016 at 12:00:31PM -0700, Joel Fernandes wrote: >> Ok. So I'll submit a patch with mutex for purge_lock and use >> cond_resched_lock for the vmap_area_lock as you suggested. I'll also >> drop the lazy_max_pages to 8MB as Andi s

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-09 Thread Chris Wilson
On Sun, Oct 09, 2016 at 12:00:31PM -0700, Joel Fernandes wrote: > Ok. So I'll submit a patch with mutex for purge_lock and use > cond_resched_lock for the vmap_area_lock as you suggested. I'll also > drop the lazy_max_pages to 8MB as Andi suggested to reduce the lock > hold time. Let me know if you

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-09 Thread Joel Fernandes
On Sun, Oct 9, 2016 at 5:42 AM, Chris Wilson wrote: [..] >> > My understanding is that >> > >> > diff --git a/mm/vmalloc.c b/mm/vmalloc.c >> > index 91f44e78c516..3f7c6d6969ac 100644 >> > --- a/mm/vmalloc.c >> > +++ b/mm/vmalloc.c >> > @@ -626,7 +626,6 @@ void set_iounmap_nonlazy(void) >> > stati

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-09 Thread Chris Wilson
On Sat, Oct 08, 2016 at 08:43:51PM -0700, Joel Fernandes wrote: > On Thu, Sep 29, 2016 at 1:18 AM, Chris Wilson > wrote: > > On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: > >> On Marvell berlin arm64 platforms, I see the preemptoff tracer report > >> a max 26543 us latency at __p

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-10-08 Thread Joel Fernandes
On Thu, Sep 29, 2016 at 1:18 AM, Chris Wilson wrote: > On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: >> On Marvell berlin arm64 platforms, I see the preemptoff tracer report >> a max 26543 us latency at __purge_vmap_area_lazy, this latency is an >> awfully bad for STB. And the ftr

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-09-29 Thread Jisheng Zhang
On Thu, 29 Sep 2016 12:07:14 +0100 Chris Wilson wrote: > On Thu, Sep 29, 2016 at 04:28:08PM +0800, Jisheng Zhang wrote: > > On Thu, 29 Sep 2016 09:18:18 +0100 Chris Wilson wrote: > > > > > On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: > > > > On Marvell berlin arm64 platforms

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-09-29 Thread Chris Wilson
On Thu, Sep 29, 2016 at 04:28:08PM +0800, Jisheng Zhang wrote: > On Thu, 29 Sep 2016 09:18:18 +0100 Chris Wilson wrote: > > > On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: > > > On Marvell berlin arm64 platforms, I see the preemptoff tracer report > > > a max 26543 us latency at _

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-09-29 Thread Jisheng Zhang
On Thu, 29 Sep 2016 09:18:18 +0100 Chris Wilson wrote: > On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: > > On Marvell berlin arm64 platforms, I see the preemptoff tracer report > > a max 26543 us latency at __purge_vmap_area_lazy, this latency is an > > awfully bad for STB. And th

Re: [PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-09-29 Thread Chris Wilson
On Thu, Sep 29, 2016 at 03:34:11PM +0800, Jisheng Zhang wrote: > On Marvell berlin arm64 platforms, I see the preemptoff tracer report > a max 26543 us latency at __purge_vmap_area_lazy, this latency is an > awfully bad for STB. And the ftrace log also shows __free_vmap_area > contributes most late

[PATCH] mm/vmalloc: reduce the number of lazy_max_pages to reduce latency

2016-09-29 Thread Jisheng Zhang
On Marvell berlin arm64 platforms, I see the preemptoff tracer report a max 26543 us latency at __purge_vmap_area_lazy, this latency is an awfully bad for STB. And the ftrace log also shows __free_vmap_area contributes most latency now. I noticed that Joel mentioned the same issue[1] on x86 platfor