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From: Steven Rostedt <rostedt@goodmis.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thorsten Glaser <tg@debian.org>,
	Peter Zijlstra <peterz@infradead.org>,
	x86@kernel.org, torvalds@linuxfoundation.org,
	linux-kernel@vger.kernel.org, linux-toolchains@vger.kernel.org,
	jpoimboe@redhat.com, alexei.starovoitov@gmail.com,
	mhiramat@kernel.org
Subject: Re: [PATCH 1/2] x86: Remove dynamic NOP selection
Date: Sun, 21 Jan 2024 21:22:36 -0500	[thread overview]
Message-ID: <20240121212236.02331f4c@rorschach.local.home> (raw)
In-Reply-To: <020a1803-25c4-4365-8c53-291becd94632@zytor.com>

On Sun, 21 Jan 2024 18:15:39 -0800
"H. Peter Anvin" <hpa@zytor.com> wrote:

> On 1/21/24 16:56, Steven Rostedt wrote:
> >>
> >> Yes, but it is a matter of where we optimize for performance as opposed to correctness.  
> > 
> > There is no such thing as "optimize for correctness", it is either
> > correct or it is not. Correctness should always come before performance
> > (at least that is what Thomas has pounded into me ;-)
> > 
> > If a kernel use to work on a machine but a newer version no longer
> > works, I call that a regression.
> >   
> 
> There absolutely is such a thing as "optimize for correctness." It means 
> to keep the code clean, easily testable, and with a minimal number of 
> distinct code paths so that regressions and *especially* uncaught 
> regressions get caught quickly.

I call that maintainability, not correctness. It is either correct and
works, or is incorrect and does not work.

You can change code to be more maintainable and still make it incorrect.

-- Steve

  reply	other threads:[~2024-01-22  2:22 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-12 11:32 [PATCH 0/2] x86: Remove ideal_nops[] Peter Zijlstra
2021-03-12 11:32 ` [PATCH 1/2] x86: Remove dynamic NOP selection Peter Zijlstra
2021-03-12 12:09   ` Peter Zijlstra
2021-03-12 20:36     ` Linus Torvalds
2024-01-20  6:58   ` Thorsten Glaser
2024-01-20  8:22     ` H. Peter Anvin
2024-01-20 16:53       ` Thorsten Glaser
2024-01-21 23:21         ` H. Peter Anvin
2024-01-21 23:58           ` Thorsten Glaser
2024-01-22  0:15             ` H. Peter Anvin
2024-01-22  0:56               ` Steven Rostedt
2024-01-22  1:17                 ` Thorsten Glaser
2024-01-22  2:04                   ` H. Peter Anvin
2024-01-22  2:15                 ` H. Peter Anvin
2024-01-22  2:22                   ` Steven Rostedt [this message]
2024-01-22  2:31                     ` H. Peter Anvin
2024-01-20 17:00       ` Linus Torvalds
2024-01-20 17:19         ` Thorsten Glaser
2024-01-20 18:21           ` disassemblers (was Re: [PATCH 1/2] x86: Remove dynamic NOP selection) Thorsten Glaser
2024-01-21 22:36         ` [PATCH 1/2] x86: Remove dynamic NOP selection David Laight
2024-01-21 23:10           ` H. Peter Anvin
2021-03-12 11:32 ` [PATCH 2/2] objtool,x86: Use asm/nops.h Peter Zijlstra
2021-03-12 14:29 ` [PATCH 0/2] x86: Remove ideal_nops[] Sedat Dilek
2021-03-12 14:47   ` Borislav Petkov
2021-03-12 17:26     ` Steven Rostedt
2021-03-12 17:35       ` Sedat Dilek
2021-03-12 17:46         ` Borislav Petkov
2021-03-12 17:47         ` Steven Rostedt
2021-03-12 18:13           ` Sedat Dilek
2021-03-12 19:03             ` Sedat Dilek
2021-03-12 20:59 ` Borislav Petkov
     [not found]   ` <CA+icZUWSCS6vAQOXoG6nsW+Dbnogivzf+rmegCTMjz5hjE5cKQ@mail.gmail.com>
2021-03-13  8:49     ` Borislav Petkov
2021-03-13 11:23       ` Borislav Petkov
2021-03-13 12:10       ` Sedat Dilek
2021-03-13 12:15         ` Borislav Petkov
2021-03-13 12:38           ` Sedat Dilek
2021-03-13 12:49             ` Borislav Petkov
2021-03-13 12:58               ` Sedat Dilek
2021-03-13 13:29                 ` Borislav Petkov
2021-03-13 13:47                   ` Sedat Dilek
2021-03-15 17:04                     ` Sedat Dilek
2021-03-15 17:15                       ` Borislav Petkov
2021-03-15 17:19                         ` Sedat Dilek
2021-03-15 17:23                           ` Borislav Petkov
2021-03-15 18:10                       ` Peter Zijlstra
2021-03-15 18:23                         ` Sedat Dilek
2021-03-15 22:14                           ` Peter Zijlstra
2021-03-16  5:56                             ` Sedat Dilek
2021-03-27 12:08                               ` Sedat Dilek
2021-03-27 20:02                                 ` Linus Torvalds
2021-03-30 12:31                                   ` Sedat Dilek

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