linux-kernel - Re: [PATCH 2/7] mm: shrinker: Add a .to

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]

Message-ID: <20231128174853.vdpwullepoxg5blo@moria.home.lan>
Date:   Tue, 28 Nov 2023 12:48:53 -0500
From:   Kent Overstreet <kent.overstreet@...ux.dev>
To:     Michal Hocko <mhocko@...e.com>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Qi Zheng <zhengqi.arch@...edance.com>,
        Roman Gushchin <roman.gushchin@...ux.dev>
Subject: Re: [PATCH 2/7] mm: shrinker: Add a .to_text() method for shrinkers

On Tue, Nov 28, 2023 at 11:01:16AM +0100, Michal Hocko wrote:
> On Wed 22-11-23 18:25:07, Kent Overstreet wrote:
> [...]
> > +void shrinkers_to_text(struct seq_buf *out)
> > +{
> > +	struct shrinker *shrinker;
> > +	struct shrinker_by_mem {
> > +		struct shrinker	*shrinker;
> > +		unsigned long	mem;
> > +	} shrinkers_by_mem[10];
> > +	int i, nr = 0;
> > +
> > +	if (!mutex_trylock(&shrinker_mutex)) {
> > +		seq_buf_puts(out, "(couldn't take shrinker lock)");
> > +		return;
> > +	}
> > +
> > +	list_for_each_entry(shrinker, &shrinker_list, list) {
> > +		struct shrink_control sc = { .gfp_mask = GFP_KERNEL, };
> 
> This seems to be global reclaim specific. What about memcg reclaim?

I have no fsckin idea how memcg reclaim works - and, for that matter,
the recent lockless shrinking work seems to have neglected to write even
an iterator macro, leaving _that_ a nasty mess so I'm not touching that
either.