From: Linus Torvalds <torvalds@linux-foundation.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>,
Steven Rostedt <rostedt@goodmis.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH 1/2] x86/nmi: Optimize the check for being in the repeat_nmi code
Date: Fri, 10 Mar 2017 11:00:43 -0800 [thread overview]
Message-ID: <CA+55aFxw0JLDVBQwHuV-0UyPsM-npMH9CS=g8d1drmedpViVvw@mail.gmail.com> (raw)
In-Reply-To: <20170310072056.GA3762@gmail.com>
On Thu, Mar 9, 2017 at 11:20 PM, Ingo Molnar <mingo@kernel.org> wrote:
>
> Joking aside, I'll bite: while in the kernel we try to avoid ever actually
> _writing_ new assembly code
.. also, when we do, I think we should care about it.
If you write asm, and the end result is noticeably worse than what
your average compiler would generate, exactly why are you writing it
in asm in the first place?
So I think people should aim to avoid asm. Andy certainly knows that,
and I loved his "rewrite a lot of the low-level system call code"
patches.
But the corollary to that is that if you _do_ write assembler, please
have some pride in the code, and don't half-arse it.
Linus
next prev parent reply other threads:[~2017-03-10 19:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-09 22:42 [PATCH 0/2] x86/nmi: Optimize address compares with better jump algorithm Steven Rostedt
2017-03-09 22:42 ` [PATCH 1/2] x86/nmi: Optimize the check for being in the repeat_nmi code Steven Rostedt
2017-03-10 2:42 ` Andy Lutomirski
2017-03-10 3:49 ` Steven Rostedt
2017-03-10 3:50 ` Andy Lutomirski
2017-03-10 7:20 ` Ingo Molnar
2017-03-10 19:00 ` Linus Torvalds [this message]
2017-03-10 19:03 ` Andy Lutomirski
2017-03-09 22:42 ` [PATCH 2/2] x86/nmi: Fix and optimize the NMI stack check code Steven Rostedt
2017-03-10 2:43 ` Andy Lutomirski
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