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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: "the arch/x86 maintainers" <x86@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Oleg Nesterov <oleg@redhat.com>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [RFC 00/13] x86/mm: PCID and INVPCID
Date: Fri, 8 Jan 2016 15:31:03 -0800	[thread overview]
Message-ID: <CA+55aFxpGj2koqmcFF9JWzBeheF9473Ka516shwbuhfjVpgxrg@mail.gmail.com> (raw)
In-Reply-To: <cover.1452294700.git.luto@kernel.org>

On Fri, Jan 8, 2016 at 3:15 PM, Andy Lutomirski <luto@kernel.org> wrote:
>
> Please play around and suggest (and run?) good benchmarks.  It seems
> to save around 100ns on cross-process context switches for me.

Interesting. There was reportedly (I never saw it) a test-patch to use
pcids inside of Intel a couple of years ago, and it never got outside
because it didn't make a difference.

Either things have changed (newer hardware with more pcids perhaps?)
or you did a better job at it.

              Linus

  parent reply	other threads:[~2016-01-08 23:31 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-08 23:15 [RFC 00/13] x86/mm: PCID and INVPCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 01/13] x86/paravirt: Turn KASAN off for parvirt.o Andy Lutomirski
2016-01-10 18:59   ` Borislav Petkov
2016-01-11 12:51     ` Andrey Ryabinin
2016-01-11 12:51       ` [PATCH 1/2] x86/kasan: clear kasan_zero_page after TLB flush Andrey Ryabinin
2016-01-18 22:24         ` Andy Lutomirski
2016-02-09 16:06         ` [tip:x86/mm] x86/kasan: Clear " tip-bot for Andrey Ryabinin
2016-01-11 12:51       ` [PATCH 2/2] x86/kasan: write protect kasan zero shadow Andrey Ryabinin
2016-01-18 22:24         ` Andy Lutomirski
2016-02-09 16:07         ` [tip:x86/mm] x86/kasan: Write " tip-bot for Andrey Ryabinin
2016-01-29 10:35       ` [RFC 01/13] x86/paravirt: Turn KASAN off for parvirt.o Borislav Petkov
2016-01-08 23:15 ` [RFC 02/13] x86/mm: Add INVPCID helpers Andy Lutomirski
2016-01-08 23:15 ` [RFC 03/13] x86/mm: Add a noinvpcid option to turn off INVPCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 04/13] x86/mm: If INVPCID is available, use it to flush global mappings Andy Lutomirski
2016-01-08 23:15 ` [RFC 05/13] x86/mm: Add barriers and document switch_mm-vs-flush synchronization Andy Lutomirski
2016-06-03 17:42   ` Nadav Amit
2016-06-09 17:24     ` Andy Lutomirski
2016-06-09 19:45       ` Nadav Amit
2016-09-06  1:22   ` Wanpeng Li
2016-01-08 23:15 ` [RFC 06/13] x86/mm: Disable PCID on 32-bit kernels Andy Lutomirski
2016-01-08 23:15 ` [RFC 07/13] x86/mm: Add nopcid to turn off PCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 08/13] x86/mm: Teach CR3 readers about PCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 09/13] x86/mm: Disable interrupts when flushing the TLB using CR3 Andy Lutomirski
2016-01-08 23:41   ` Linus Torvalds
2016-01-09  0:18     ` Andy Lutomirski
2016-01-09  2:20       ` Linus Torvalds
2016-01-11 10:51         ` Ingo Molnar
2016-01-13 23:32           ` Andy Lutomirski
2016-01-13 23:35         ` Andy Lutomirski
2016-01-13 23:43           ` Dave Hansen
2016-01-13 23:51             ` Andy Lutomirski
2016-01-13 23:56               ` Dave Hansen
2016-01-14  0:34                 ` Andy Lutomirski
2016-01-08 23:15 ` [RFC 10/13] x86/mm: Factor out remote TLB flushing Andy Lutomirski
2016-01-08 23:15 ` [RFC 11/13] x86/mm: Build arch/x86/mm/tlb.c even on !SMP Andy Lutomirski
2016-01-08 23:55   ` Dave Hansen
2016-01-08 23:15 ` [RFC 12/13] x86/mm: Uninline switch_mm Andy Lutomirski
2016-01-08 23:15 ` [RFC 13/13] x86/mm: Try to preserve old TLB entries using PCID Andy Lutomirski
2016-01-09  0:27   ` Dave Hansen
2016-01-09  2:19     ` Andy Lutomirski
2016-01-08 23:31 ` Linus Torvalds [this message]
2016-01-08 23:36   ` [RFC 00/13] x86/mm: PCID and INVPCID Andy Lutomirski
2016-01-08 23:42     ` Linus Torvalds

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