From: Peter Zijlstra <peterz@infradead.org>
To: Andrew.Cooper3@citrix.com
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
mhiramat@kernel.org, kirill.shutemov@linux.intel.com,
jpoimboe@redhat.com
Subject: Re: [PATCH v3 3/4] x86/alternative: Rewrite optimize_nops() some
Date: Wed, 8 Feb 2023 21:45:39 +0100 [thread overview]
Message-ID: <Y+QJ81i/QL+Cp1bf@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <Y+QJlK637EYg/Zst@hirez.programming.kicks-ass.net>
On Wed, Feb 08, 2023 at 09:44:04PM +0100, Peter Zijlstra wrote:
> GNU as seems to go to .nops 12. 13 gives me a single byte nop and a 12.
> That's also exactly the 3 prefix limit, after which some uarchs start
> taking heavy decode penalties.
Oh noes, counting hard. It maxes out at 11, not 12. Sadness.
Instead, lemme go figure out what those alternatives actually are.
next prev parent reply other threads:[~2023-02-08 20:45 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-08 17:10 [PATCH v3 0/4] x86: Fully relocatable alternatives and some NOPs Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 1/4] x86/alternative: Make debug-alternative selective Peter Zijlstra
2023-02-14 11:48 ` Borislav Petkov
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 2/4] x86/alternative: Support relocations in alternatives Peter Zijlstra
2023-02-17 20:28 ` Borislav Petkov
2023-02-17 22:21 ` Borislav Petkov
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-08 17:10 ` [PATCH v3 3/4] x86/alternative: Rewrite optimize_nops() some Peter Zijlstra
2023-02-08 19:52 ` Andrew.Cooper3
2023-02-08 20:29 ` Peter Zijlstra
2023-02-08 20:36 ` Peter Zijlstra
2023-02-08 20:44 ` Peter Zijlstra
2023-02-08 20:45 ` Peter Zijlstra [this message]
2023-02-08 21:01 ` Peter Zijlstra
2023-02-08 21:08 ` Peter Zijlstra
2023-02-08 21:21 ` Peter Zijlstra
2023-02-09 1:11 ` Andrew.Cooper3
2023-02-09 22:27 ` David Laight
2023-02-09 1:33 ` Andrew.Cooper3
2023-02-08 23:04 ` David Laight
2023-05-13 13:03 ` [tip: x86/alternatives] " tip-bot2 for Peter Zijlstra
2023-02-27 10:49 ` [PATCH] x86/lib/memmove: Decouple ERMS from FSRM Borislav Petkov
2023-04-27 9:22 ` [PATCH TEST] " Yahu Gao
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