linux-kernel - Re: [PATCH 0/7] minmax: reduce compilation time

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] [day] [month] [year] [list]

Message-Id: <d9c9c4ac-c3b5-4936-bfd7-13d7260de33d@app.fastmail.com>
Date: Tue, 30 Jul 2024 12:36:39 +0200
From: "Arnd Bergmann" <arnd@...nel.org>
To: "Linus Torvalds" <torvalds@...uxfoundation.org>,
 "Lorenzo Stoakes" <lorenzo.stoakes@...cle.com>
Cc: "David Laight" <David.Laight@...lab.com>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "Matthew Wilcox" <willy@...radead.org>,
 "Christoph Hellwig" <hch@...radead.org>,
 "Andrew Morton" <akpm@...ux-foundation.org>,
 "Andy Shevchenko" <andriy.shevchenko@...ux.intel.com>,
 "Dan Carpenter" <dan.carpenter@...aro.org>,
 "Jason A . Donenfeld" <Jason@...c4.com>,
 "pedro.falcato@...il.com" <pedro.falcato@...il.com>,
 "Mateusz Guzik" <mjguzik@...il.com>,
 "linux-mm@...ck.org" <linux-mm@...ck.org>
Subject: Re: [PATCH 0/7] minmax: reduce compilation time

On Tue, Jul 30, 2024, at 06:10, Linus Torvalds wrote:
>
> Of course, I never did any build timings. I'm not sure how much it
> actually shows up on that level. A couple of bad cases won't be *that*
> noticeable when most cases aren't too horrid.

I did a little bit of build timing last week, which confirms
exactly what you expect here: On individual files, the difference
can easily be 1000x faster, like on that arch/x86/xen/setup.c
file, but overall the difference in build speed for an allmodconfig
or defconfig build was between 1% and 3%, depending on how many
of the extreme cases are included.

Of course, it would be easy to take one of the extreme cases and
add another expansion that then drives the memory usage and/or
compile time up to a point where the build fails.

       Arnd