From: Rik van Riel <riel@surriel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com,
mingo@kernel.org, luto@kernel.org, x86@kernel.org, efault@gmx.de,
dave.hansen@intel.com
Subject: Re: [PATCH 11/11] mm,sched: conditionally skip lazy TLB mm refcounting
Date: Fri, 03 Aug 2018 13:39:52 -0400 [thread overview]
Message-ID: <1533317992.28585.103.camel@surriel.com> (raw)
In-Reply-To: <20180803172516.GM2458@hirez.programming.kicks-ass.net>
[-- Attachment #1: Type: text/plain, Size: 1304 bytes --]
On Fri, 2018-08-03 at 19:25 +0200, Peter Zijlstra wrote:
> On Fri, Aug 03, 2018 at 12:40:48PM -0400, Rik van Riel wrote:
> > On Fri, 2018-08-03 at 17:56 +0200, Peter Zijlstra wrote:
> > >
> > > Why can't we skip the ->active_mm swizzle and keep ->active_mm ==
> > > ->mm.
> > >
> > > Doing the swizzle but not the refcount just makes me itch.
> >
> > I am working on that now, it adds another 7-8
> > patches on top of this series.
>
> I thought those were taking ->active_mm out entirely, not avoiding
> the
> swizzle, but I might have missed something in the middle :-)
At this point, only the fact that ->active_mm is still
being used by a few places in the code :)
> > The big question is, do we want this optimization
> > to wait for further cleanups, or should we run with
> > code that seems to be stable right now, and put
> > additional cleanups and enhancements on top of it
> > later?
>
> At the very least the Changelog needs to explain why we cannot do
> away
> with the swizzle now and how doing the swizzle without the
> refcounting
> is not completely broken (I think I see, but urgh).
The changelog for patches 9 & 10 explains, I think.
What is missing from my explanation?
How would you like to see it explained?
--
All Rights Reversed.
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2018-08-03 17:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 10:02 [PATCH v2 0/11] x86,tlb,mm: more lazy TLB cleanups & optimizations Rik van Riel
2018-08-01 10:02 ` [PATCH 01/11] x86,tlb: clarify memory barrier in switch_mm_irqs_off Rik van Riel
2018-08-01 10:02 ` [PATCH 02/11] smp: use __cpumask_set_cpu in on_each_cpu_cond Rik van Riel
2018-08-01 10:02 ` [PATCH 03/11] smp,cpumask: introduce on_each_cpu_cond_mask Rik van Riel
2018-08-01 10:02 ` [PATCH 04/11] x86,mm: use on_each_cpu_cond for TLB flushes Rik van Riel
2018-08-01 10:02 ` [PATCH 05/11] mm,tlb: turn dummy defines into inline functions Rik van Riel
2018-08-01 10:02 ` [PATCH 06/11] mm,x86: skip cr4 and ldt reload when mm stays the same Rik van Riel
2018-08-01 10:02 ` [PATCH 07/11] x86,mm: remove leave_mm cpu argument Rik van Riel
2018-08-01 10:02 ` [PATCH 08/11] arch,mm: add config variable to skip lazy TLB mm refcounting Rik van Riel
2018-08-01 10:02 ` [PATCH 09/11] mm,x86: shoot down lazy TLB references at exit_mmap time Rik van Riel
2018-08-01 10:02 ` [PATCH 10/11] x86,tlb: really leave mm on shootdown Rik van Riel
2018-08-01 10:02 ` [PATCH 11/11] mm,sched: conditionally skip lazy TLB mm refcounting Rik van Riel
2018-08-03 15:56 ` Peter Zijlstra
2018-08-03 16:40 ` Rik van Riel
2018-08-03 17:25 ` Peter Zijlstra
2018-08-03 17:39 ` Rik van Riel [this message]
2018-08-06 17:50 ` Peter Zijlstra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1533317992.28585.103.camel@surriel.com \
--to=riel@surriel.com \
--cc=dave.hansen@intel.com \
--cc=efault@gmx.de \
--cc=kernel-team@fb.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox