linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Nicholas Piggin <npiggin@gmail.com>,
	Anton Blanchard <anton@ozlabs.org>, Arnd Bergmann <arnd@arndb.de>,
	linux-arch <linux-arch@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Linux-MM <linux-mm@kvack.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
	Andy Lutomirski <luto@kernel.org>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	X86 ML <x86@kernel.org>
Subject: Re: [RFC PATCH 7/7] lazy tlb: shoot lazies, a non-refcounting lazy tlb option
Date: Tue, 14 Jul 2020 15:23:41 +0200	[thread overview]
Message-ID: <20200714132341.GY10769@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <6D3D1346-DB1E-43EB-812A-184918CCC16A@amacapital.net>

On Tue, Jul 14, 2020 at 05:46:05AM -0700, Andy Lutomirski wrote:
> x86 has this exact problem. At least no more than 64*8 CPUs share the cache line :)

I've seen patches for a 'sparse' bitmap to solve related problems.

It's basically the same code, except it multiplies everything (size,
bit-nr) by a constant to reduce the number of active bits per line.

This sadly doesn't take topology into account, but reducing contention
is still good ofcourse.


  reply	other threads:[~2020-07-14 13:23 UTC|newest]

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-10  1:56 [RFC PATCH 0/7] mmu context cleanup, lazy tlb cleanup, Nicholas Piggin
2020-07-10  1:56 ` [RFC PATCH 1/7] asm-generic: add generic MMU versions of mmu context functions Nicholas Piggin
2020-07-10  1:56 ` [RFC PATCH 2/7] arch: use asm-generic mmu context for no-op implementations Nicholas Piggin
2020-07-10  1:56 ` [RFC PATCH 3/7] mm: introduce exit_lazy_tlb Nicholas Piggin
2020-07-10  1:56 ` [RFC PATCH 4/7] x86: use exit_lazy_tlb rather than membarrier_mm_sync_core_before_usermode Nicholas Piggin
2020-07-10  9:42   ` Peter Zijlstra
2020-07-10 14:02   ` Mathieu Desnoyers
2020-07-10 17:04   ` Andy Lutomirski
2020-07-13  4:45     ` Nicholas Piggin
2020-07-13 13:47       ` Nicholas Piggin
2020-07-13 14:13         ` Mathieu Desnoyers
2020-07-13 15:48           ` Andy Lutomirski
2020-07-13 16:37             ` Nicholas Piggin
2020-07-16  4:15           ` Nicholas Piggin
2020-07-16  4:42             ` Nicholas Piggin
2020-07-16 15:46               ` Mathieu Desnoyers
2020-07-16 16:03                 ` Mathieu Desnoyers
2020-07-16 18:58                   ` Mathieu Desnoyers
2020-07-16 21:24                     ` Alan Stern
2020-07-17 13:39                       ` Mathieu Desnoyers
2020-07-17 14:51                         ` Alan Stern
2020-07-17 15:39                           ` Mathieu Desnoyers
2020-07-17 16:11                             ` Alan Stern
2020-07-17 16:22                               ` Mathieu Desnoyers
2020-07-17 17:44                                 ` Alan Stern
2020-07-17 17:52                                   ` Mathieu Desnoyers
2020-07-17  0:00                     ` Nicholas Piggin
2020-07-16  5:18             ` Andy Lutomirski
2020-07-16  6:06               ` Nicholas Piggin
2020-07-16  8:50               ` Peter Zijlstra
2020-07-16 10:03                 ` Nicholas Piggin
2020-07-16 11:00                   ` peterz
2020-07-16 15:34                     ` Mathieu Desnoyers
2020-07-16 23:26                     ` Nicholas Piggin
2020-07-17 13:42                       ` Mathieu Desnoyers
2020-07-20  3:03                         ` Nicholas Piggin
2020-07-20 16:46                           ` Mathieu Desnoyers
2020-07-21 10:04                             ` Nicholas Piggin
2020-07-21 13:11                               ` Mathieu Desnoyers
2020-07-21 14:30                                 ` Nicholas Piggin
2020-07-21 15:06                               ` peterz
2020-07-21 15:15                                 ` Mathieu Desnoyers
2020-07-21 15:19                                   ` Peter Zijlstra
2020-07-21 15:22                                     ` Mathieu Desnoyers
2020-07-10  1:56 ` [RFC PATCH 5/7] lazy tlb: introduce lazy mm refcount helper functions Nicholas Piggin
2020-07-10  9:48   ` Peter Zijlstra
2020-07-10  1:56 ` [RFC PATCH 6/7] lazy tlb: allow lazy tlb mm switching to be configurable Nicholas Piggin
2020-07-10  1:56 ` [RFC PATCH 7/7] lazy tlb: shoot lazies, a non-refcounting lazy tlb option Nicholas Piggin
2020-07-10  9:35   ` Peter Zijlstra
2020-07-13  4:58     ` Nicholas Piggin
2020-07-13 15:59   ` Andy Lutomirski
2020-07-13 16:48     ` Nicholas Piggin
2020-07-13 18:18       ` Andy Lutomirski
2020-07-14  5:04         ` Nicholas Piggin
2020-07-14  6:31           ` Nicholas Piggin
2020-07-14 12:46             ` Andy Lutomirski
2020-07-14 13:23               ` Peter Zijlstra [this message]
2020-07-16  2:26               ` Nicholas Piggin
2020-07-16  2:35               ` Nicholas Piggin

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=20200714132341.GY10769@hirez.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=anton@ozlabs.org \
    --cc=arnd@arndb.de \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=luto@amacapital.net \
    --cc=luto@kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=npiggin@gmail.com \
    --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