Re: [RFC][PATCH 2/5] [PATCH 2/5] proc: introduce /proc/PID/idle_bitmap

2018-09-06 Thread Dave Hansen
On 09/01/2018 04:28 AM, Fengguang Wu wrote: > To walk 1TB memory of 4k active pages, it costs 2s vs 15s system > time to scan the per-task/global idle bitmaps. To me, that says this interface simply won't work on large systems. 2s and 15s are both simply unacceptably long. > OTOH, the per-task

Re: [RFC][PATCH 2/5] [PATCH 2/5] proc: introduce /proc/PID/idle_bitmap

2018-09-06 Thread Dave Hansen
On 09/01/2018 04:28 AM, Fengguang Wu wrote: > To walk 1TB memory of 4k active pages, it costs 2s vs 15s system > time to scan the per-task/global idle bitmaps. To me, that says this interface simply won't work on large systems. 2s and 15s are both simply unacceptably long. > OTOH, the per-task

Re: [RFC][PATCH 2/5] [PATCH 2/5] proc: introduce /proc/PID/idle_bitmap

2018-09-04 Thread Sean Christopherson
On Sat, Sep 01, 2018 at 07:28:20PM +0800, Fengguang Wu wrote: > diff --git a/fs/proc/internal.h b/fs/proc/internal.h > index da3dbfa09e79..732a502acc27 100644 > --- a/fs/proc/internal.h > +++ b/fs/proc/internal.h > @@ -305,6 +305,7 @@ extern const struct file_operations >

Re: [RFC][PATCH 2/5] [PATCH 2/5] proc: introduce /proc/PID/idle_bitmap

2018-09-04 Thread Sean Christopherson
On Sat, Sep 01, 2018 at 07:28:20PM +0800, Fengguang Wu wrote: > diff --git a/fs/proc/internal.h b/fs/proc/internal.h > index da3dbfa09e79..732a502acc27 100644 > --- a/fs/proc/internal.h > +++ b/fs/proc/internal.h > @@ -305,6 +305,7 @@ extern const struct file_operations >