From: "Martin Liška" <mliska@suse.cz>
To: Dmitry Vyukov <dvyukov@google.com>, gcc <gcc@gcc.gnu.org>
Cc: ro@gcc.gnu.org, "Jakub Jelinek" <jakub@redhat.com>,
"Martin Liška" <marxin@gcc.gnu.org>,
"Marco Elver" <elver@google.com>,
"Alexander Potapenko" <glider@google.com>
Subject: Re: New ThreadSanitizer runtime (v3)
Date: Mon, 22 Nov 2021 19:30:55 +0100 [thread overview]
Message-ID: <1b8fa4e6-7a78-cdbb-c06d-fe7cd58d1e76@suse.cz> (raw)
In-Reply-To: <CACT4Y+bvVooxDChy120qBz2jaT6=HVw+e+ZtGeaxUut4ND+FNg@mail.gmail.com>
On 11/22/21 16:22, Dmitry Vyukov wrote:
> Hi gcc developers,
Hello.
>
> I wanted to give heads up regarding a significant re-design of the
Thanks for it.
> ThreadSanitizer runtime:
> https://reviews.llvm.org/D112603
> Currently it's submitted:
> https://github.com/llvm/llvm-project/commit/1784fe0532a69ead17793bced060a9bf9d232027
> but can well be rolled back if too many buildbots fail, but should be
> submitted again soon anyway.
>
> It was extensively tested and lots of bugs were fixed, but it's still
> possible it will cause some issues just because of the size of the
> change and OS/arch sensitivity.
>
> For a wide range of real programs it provides 20%-4x speedup on x86_64
> and 20-40% memory consumption reduction.
That are all good news!
>
> One issue that will come up with gcc is the use of the new
> disable_sanitizer_instrumentation attribute in tests:
> https://clang.llvm.org/docs/AttributeReference.html#disable-sanitizer-instrumentation
> e.g.:
> https://github.com/llvm/llvm-project/blob/1784fe0532a69ead17793bced060a9bf9d232027/compiler-rt/test/tsan/java_symbolization.cpp#L5
Well, apparently the tsan tests (similarly to other Sanitizer) are not synchronized and we
only have a small subset of test.
Right now I'm working on the libsanitizer's merge from master and tsan.exp tests work fine.
> ThreadSanitizer is now more picky about recursing from runtime
> callbacks back into runtime.
> You may either disable these tests, or move callbacks into
> non-instrumented files (though, will require forking tests), or
> implement the attribute.
> Some uses of the disable_sanitizer_instrumentation attribute were also
> discussed in the Linux kernel context. KMSAN will use it and kernel
> noinstr functions could use it, though currently noinstr functions are
> post-processed with kernel's objtool, which nops any sanitizer
> callbacks. The objtool approach will continue to work, so it's not
> that the attribute is mandated.
>
Right now, we as GCC have no_sanitize ("sanitize_option") that can be used (or no_sanitize_* attributes).
Can you please explain why did you invent the new flag?
Cheers,
Martin
next prev parent reply other threads:[~2021-11-22 18:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-22 15:22 Dmitry Vyukov
2021-11-22 18:30 ` Martin Liška [this message]
2021-11-22 19:00 ` Dmitry Vyukov
2021-11-22 19:07 ` Martin Liška
2021-11-22 19:54 ` Marco Elver
2021-11-22 19:20 ` Jakub Jelinek
2021-11-22 18:38 ` Martin Liška
2021-11-22 19:01 ` Dmitry Vyukov
2021-11-29 18:16 ` Martin Liška
2021-11-30 4:17 ` Dmitry Vyukov
2021-12-23 12:10 ` Martin Liška
2021-12-23 12:21 ` Dmitry Vyukov
2021-11-23 13:49 ` Florian Weimer
2021-11-23 13:51 ` Dmitry Vyukov
2021-11-23 13:59 ` Florian Weimer
2021-11-23 15:37 ` Dmitry Vyukov
2021-11-23 16:16 ` Florian Weimer
2021-11-23 16:52 ` Dmitry Vyukov
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