lkml.org 
[lkml]   [2017]   [Sep]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Current mainline git (24e700e291d52bd2) hangs when building e.g. perf
From
Date


> On Sep 10, 2017, at 1:22 PM, Peter Zijlstra <peterz@infradead.org> wrote:
>
>> On Sat, Sep 09, 2017 at 09:42:12PM -0700, Andy Lutomirski wrote:
>> PeterZ and Ingo, would you be okay with adding a define so arches can
>> opt out of the task_struct::active_mm field entirely? That is, with
>> the option set, task_struct wouldn't have an active_mm field, the core
>> wouldn't call mmgrab and mmdrop, and the arch would be responsible for
>> that bookkeeping instead? x86, and presumably all arches without
>> cross-core invalidation, would probably prefer to just shoot down the
>> old mm entirely in __mmput() rather than trying to figure out when do
>> finish freeing old mms. After all, exit_mmap() is going to send an
>> IPI regardless, so I see no reason to have the scheduler core pin an
>> old dead mm just because some random kernel thread's active_mm field
>> points to it.
>
> I'm only quickly skimming this thread, but I don't see anything too
> worrysome being proposed.
>
> If you're in LA next week we can talk about it in more detail if you
> want.

I'll be there.

\
 
 \ /
  Last update: 2017-09-10 22:26    [W:0.089 / U:4.048 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site