linux-kernel - Re: [PATCH 1/1] boot: Enhance performance by eliminating unnecessary calls to printf()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 14 Jun 2011 14:23:40 -0400
From:	Valdis.Kletnieks@...edu
To:	Jean Sacren <sakiwit@...il.com>
Cc:	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/1] boot: Enhance performance by eliminating unnecessary calls to printf()

On Sun, 12 Jun 2011 12:36:28 MDT, Jean Sacren said:

> Subject: [PATCH 1/1] boot: Enhance performance by eliminating unnecessary calls to printf()
> 
> Repeated calling to printf() for 13 times is a dire waste of CPU cycles.
> For performance, combine all those calls into one while source code
> formatting is preserved for readability.

*facepalm*

I defy anybody to find a *less* performance-critical piece of code to
micro-optimize. It doesn't even make a boot faster, it makes a kernel build
non-measurably faster.

If you wanted to make kernel builds faster, go look at Ingo's numbers regarding
the current #include mess - fixing *that* will be of more benefit than this...

Content of type "application/pgp-signature" skipped