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

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Message-ID: <CAHk-=whH6rJeo1WxZWQzTeEXS+8MNV=A2c4qrF-uFYjU-J6U-g@mail.gmail.com>
Date: Fri, 26 Jul 2024 15:48:50 -0700
From: Linus Torvalds <torvalds@...uxfoundation.org>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, Jens Axboe <axboe@...nel.dk>
Cc: David Laight <David.Laight@...lab.com>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, 
	"Matthew Wilcox (Oracle)" <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>, Arnd Bergmann <arnd@...nel.org>, 
	"Jason@...c4.com" <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 Fri, 26 Jul 2024 at 14:36, Linus Torvalds
<torvalds@...uxfoundation.org> wrote:
>
> LOL. At least some of that is because of 'pageblock_order', which
> expands to 2.5kB of text [..]

Ok, I pushed out my two fixes - one for the xen/setup.c case, and
another for the ridiculous 'pageblock_order' expansion.

They both looked obvious to me, and they definitely make for a notably
smaller preprocessor noise load, but maybe I messed something up.

I didn't even look at what the issue was with the
bio_for_each_segment() expansion, in the hope that Jens will make that
one look better.

There are probably many other cases where we have these kinds of "tens
of kB of macro expansion", I only looked at the xen case and the
mm/compaction.c case based on Lorenzo's list of top offenders.

                  Linus