From: Kees Cook <keescook@chromium.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Marco Elver <elver@google.com>, Bill Wendling <morbo@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Masahiro Yamada <masahiroy@kernel.org>,
Linux Doc Mailing List <linux-doc@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Andrew Morton <akpm@linux-foundation.org>,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Sami Tolvanen <samitolvanen@google.com>,
Fangrui Song <maskray@google.com>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>, Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
johannes.berg@intel.com, oberpar@linux.vnet.ibm.com,
linux-toolchains@vger.kernel.org
Subject: Re: [PATCH v9] pgo: add clang's Profile Guided Optimization infrastructure
Date: Mon, 14 Jun 2021 09:22:58 -0700 [thread overview]
Message-ID: <202106140921.5E591BD@keescook> (raw)
In-Reply-To: <20210614153545.GA68749@worktop.programming.kicks-ass.net>
On Mon, Jun 14, 2021 at 05:35:45PM +0200, Peter Zijlstra wrote:
> On Mon, Jun 14, 2021 at 08:26:01AM -0700, Kees Cook wrote:
> > So, AFAICT, the original blocking issue ("PGO does not respect noinstr")
> > is not actually an issue (noinstr contains notrace, which IS respected
> > by PGO[2]), I think this is fine to move forward.
>
> It is *NOT*: https://godbolt.org/z/9c7xdvGd9
>
> Look at how both compilers generate instrumentation in the no_instr()
> function.
Well that's disappointing. I'll put this on hold until Clang can grow an
appropriate attribute (or similar work-around). Thanks for catching
that.
--
Kees Cook
next prev parent reply other threads:[~2021-06-14 16:24 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20210111081821.3041587-1-morbo@google.com>
[not found] ` <20210407211704.367039-1-morbo@google.com>
[not found] ` <YMTn9yjuemKFLbws@hirez.programming.kicks-ass.net>
[not found] ` <CAGG=3QXjD1DQjACu=CQQSP=whue-14Pw8FcNcXrJZfLC_E+y9w@mail.gmail.com>
[not found] ` <YMT5xZsZMX0PpDKQ@hirez.programming.kicks-ass.net>
[not found] ` <CAGG=3QVHkkJ236mCJ8Jt_6JtgYtWHV9b4aVXnoj6ypc7GOnc0A@mail.gmail.com>
[not found] ` <20210612202505.GG68208@worktop.programming.kicks-ass.net>
[not found] ` <CAGG=3QUZ9tXGNLhbOr+AFDTJABDujZuaG1mYaLKdTcJZguEDWw@mail.gmail.com>
[not found] ` <YMca2aa+t+3VrpN9@hirez.programming.kicks-ass.net>
[not found] ` <CAGG=3QVPCuAx9UMTOzQp+8MJk8KVyOfaYeV0yehpVwbCaYMVpg@mail.gmail.com>
2021-06-14 10:44 ` [PATCH v9] pgo: add clang's Profile Guided Optimization infrastructure Peter Zijlstra
2021-06-14 11:41 ` Bill Wendling
2021-06-14 11:43 ` Bill Wendling
2021-06-14 14:16 ` Marco Elver
2021-06-14 15:26 ` Kees Cook
2021-06-14 15:35 ` Peter Zijlstra
2021-06-14 16:22 ` Kees Cook [this message]
2021-06-14 18:07 ` Nick Desaulniers
2021-06-14 20:49 ` Nick Desaulniers
2021-06-14 15:46 ` Peter Zijlstra
2021-06-14 16:03 ` Nick Desaulniers
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