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From: Linus Torvalds <torvalds@linux-foundation.org>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kees Cook <keescook@chromium.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Bill Wendling <morbo@google.com>, Bill Wendling <wcw@google.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	Fangrui Song <maskray@google.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Jarmo Tiitto <jarmo.tiitto@gmail.com>,
	Lukas Bulwahn <lukas.bulwahn@gmail.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Miguel Ojeda <ojeda@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Peter Oberparleiter <oberpar@linux.ibm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Will Deacon <will@kernel.org>
Subject: Re: [GIT PULL] Clang feature updates for v5.14-rc1
Date: Tue, 29 Jun 2021 14:57:49 -0700	[thread overview]
Message-ID: <CAHk-=wioxa9Ur6u+pd7shoRSHqMWn9UFKaR9D4ymj8Er2LYFFg@mail.gmail.com> (raw)
In-Reply-To: <CAKwvOdkcKU4K9LWTymmzi_c0wKPTQjWEbNu04WOd6D-EcnWDSg@mail.gmail.com>

On Tue, Jun 29, 2021 at 2:27 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> Right now we're having trouble with hardware performance counters on
> non-intel chips; I don't think we have working LBR equivalents on AMD
> until zen3, and our ETM based samples on ARM are hung up on a few last
> minute issues requiring new hardware (from multiple different chipset
> vendors).

I agree that perf profiling works best on Intel. The AMD perf side
works ok in Zen 2 from what I've seen, but needs to be a full-system
profile ("perf record -a") to use the better options, and ARM is..

But with x86 ranging from "excellent" to "usable", and ARM hopefully
being at least close to getting better proper profile data, I really
think it's the way forward, with instrumentation being a band-aid at
best.

             Linus

  reply	other threads:[~2021-06-29 22:04 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-28 19:32 [GIT PULL] Clang feature updates for v5.14-rc1 Kees Cook
2021-06-29  2:49 ` Linus Torvalds
2021-06-29 20:44   ` Kees Cook
2021-06-29 21:03     ` Linus Torvalds
2021-06-29 21:27       ` Nick Desaulniers
2021-06-29 21:57         ` Linus Torvalds [this message]
2021-07-07  8:10         ` Ingo Molnar
2021-07-02 12:46       ` Bill Wendling
2021-07-02 12:56         ` Peter Zijlstra
2021-07-02 17:26           ` Nick Desaulniers
2021-07-02 18:57             ` Peter Zijlstra
2021-07-02 19:53               ` Nick Desaulniers
2022-10-31 23:55           ` Bill Wendling
2021-06-29 13:14 ` Mark Rutland
2021-06-29 20:11   ` Kees Cook
2021-06-29 21:05   ` Nick Desaulniers
2021-10-05 13:10 ` ARCH_WANTS_NO_INSTR (Re: [GIT PULL] Clang feature updates for v5.14-rc1) Daniel Axtens
2021-10-05 13:45   ` Daniel Axtens
2021-10-05 14:30   ` Mark Rutland
2021-10-07  6:19     ` Jarmo Tiitto

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