From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, Kostya Serebryany <kcc@google.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Alexander Potapenko <glider@google.com>,
Taras Madan <tarasmadan@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
"H . J . Lu" <hjl.tools@gmail.com>,
Andi Kleen <ak@linux.intel.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Bharata B Rao <bharata@amd.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>,
Ashok Raj <ashok.raj@intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Sami Tolvanen <samitolvanen@google.com>,
ndesaulniers@google.com, joao@overdrivepizza.com
Subject: Re: [PATCHv14 08/17] x86/mm: Reduce untagged_addr() overhead until the first LAM user
Date: Tue, 17 Jan 2023 19:21:18 +0100 [thread overview]
Message-ID: <Y8bnHnLe2a+vzHDd@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wiwiA7FdSww9fTg59r5S7G-DZHtzAcq9u5zBJKYXc1agQ@mail.gmail.com>
On Tue, Jan 17, 2023 at 09:18:01AM -0800, Linus Torvalds wrote:
> But maybe even those aren't worth worrying about. At least they do the
> unmasking outside the loop - although then in the case of execve(),
> the string copies themselves are obviously done in a loop anyway.
>
> Kirill, do you have clear numbers for that static key being a noticeable win?
Numbers would be good; I think this all started as a precaution, but
clearly that's not really working out so well :/
next prev parent reply other threads:[~2023-01-17 18:21 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-11 12:37 [PATCHv14 00/17] Linear Address Masking enabling Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 01/17] x86/mm: Rework address range check in get_user() and put_user() Kirill A. Shutemov
2023-01-18 15:49 ` Peter Zijlstra
2023-01-18 15:59 ` Linus Torvalds
2023-01-18 16:48 ` Peter Zijlstra
2023-01-18 17:01 ` Linus Torvalds
2023-01-11 12:37 ` [PATCHv14 02/17] x86: Allow atomic MM_CONTEXT flags setting Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 03/17] x86: CPUID and CR3/CR4 flags for Linear Address Masking Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 04/17] x86/mm: Handle LAM on context switch Kirill A. Shutemov
2023-01-11 13:49 ` Linus Torvalds
2023-01-11 14:14 ` Kirill A. Shutemov
2023-01-11 14:37 ` [PATCHv14.1 " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 05/17] mm: Introduce untagged_addr_remote() Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 06/17] x86/uaccess: Provide untagged_addr() and remove tags before address check Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 07/17] x86/mm: Provide arch_prctl() interface for LAM Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 08/17] x86/mm: Reduce untagged_addr() overhead until the first LAM user Kirill A. Shutemov
2023-01-17 13:05 ` Peter Zijlstra
2023-01-17 13:57 ` Kirill A. Shutemov
2023-01-17 15:02 ` Peter Zijlstra
2023-01-17 17:18 ` Linus Torvalds
2023-01-17 17:28 ` Linus Torvalds
2023-01-17 18:26 ` Nick Desaulniers
2023-01-17 18:33 ` Linus Torvalds
2023-01-17 19:17 ` Nick Desaulniers
2023-01-17 20:10 ` Linus Torvalds
2023-01-17 20:43 ` Linus Torvalds
2023-01-17 18:14 ` Peter Zijlstra
2023-01-17 18:21 ` Peter Zijlstra [this message]
2023-01-19 23:06 ` Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 09/17] mm: Expose untagging mask in /proc/$PID/status Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 10/17] iommu/sva: Replace pasid_valid() helper with mm_valid_pasid() Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 11/17] x86/mm/iommu/sva: Make LAM and SVA mutually exclusive Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 12/17] selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 13/17] selftests/x86/lam: Add mmap and SYSCALL " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 14/17] selftests/x86/lam: Add io_uring " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 15/17] selftests/x86/lam: Add inherit " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 16/17] selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA " Kirill A. Shutemov
2023-01-11 12:37 ` [PATCHv14 17/17] selftests/x86/lam: Add test cases for LAM vs thread creation Kirill A. Shutemov
2023-01-18 16:49 ` [PATCHv14 00/17] Linear Address Masking enabling 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=Y8bnHnLe2a+vzHDd@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=ak@linux.intel.com \
--cc=andreyknvl@gmail.com \
--cc=ashok.raj@intel.com \
--cc=bharata@amd.com \
--cc=dave.hansen@linux.intel.com \
--cc=dvyukov@google.com \
--cc=glider@google.com \
--cc=hjl.tools@gmail.com \
--cc=jacob.jun.pan@linux.intel.com \
--cc=joao@overdrivepizza.com \
--cc=kcc@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=ndesaulniers@google.com \
--cc=rick.p.edgecombe@intel.com \
--cc=ryabinin.a.a@gmail.com \
--cc=samitolvanen@google.com \
--cc=tarasmadan@google.com \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.