linux-kernel - Re: [PATCH 1/3] lib/min_heap: Introduce non-inline versions of min heap API functions

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Message-ID: <zne3invtehte3ym34ufnydtggigxazdb2ltfa26ca4tykvprls@rcawukx5hhcn>
Date: Thu, 17 Oct 2024 06:46:15 -0400
From: Kent Overstreet <kent.overstreet@...ux.dev>
To: Peter Zijlstra <peterz@...radead.org>
Cc: Kuan-Wei Chiu <visitorckw@...il.com>, colyli@...e.de, 
	msakai@...hat.com, corbet@....net, mingo@...hat.com, acme@...nel.org, 
	namhyung@...nel.org, akpm@...ux-foundation.org, mark.rutland@....com, 
	alexander.shishkin@...ux.intel.com, jolsa@...nel.org, irogers@...gle.com, adrian.hunter@...el.com, 
	kan.liang@...ux.intel.com, jserv@...s.ncku.edu.tw, linux-kernel@...r.kernel.org, 
	linux-bcache@...r.kernel.org, dm-devel@...ts.linux.dev, linux-bcachefs@...r.kernel.org, 
	linux-perf-users@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH 1/3] lib/min_heap: Introduce non-inline versions of min
 heap API functions

On Thu, Oct 17, 2024 at 11:55:20AM +0200, Peter Zijlstra wrote:
> On Wed, Oct 16, 2024 at 11:26:30PM -0400, Kent Overstreet wrote:
> 
> > yeah, I think we would prefer smaller codesize, by default.
> > 
> > it'd be well worth checking the code size difference on inlined vs. not,
> > and then the really think to do would be to provide optional _inlined()
> > helpers that we can switch to if/when a particular codepath shows up in
> > a profile
> 
> Make sure to build with kCFI and IBT enabled when you do this and enjoy
> seeing ec_stripes_heap_cmp turn into this:

I wouldn't worry too much about the stripes heap, I'm going to replace
that with a persistent LRU.

After that it looks like the only heap left in bcachefs will be in the
clock code. Shame, they're one of my favorite data structures...