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From:   =?UTF-8?Q?Andreas_Gr=C3=BCnbacher?= <andreas.gruenbacher@gmail.com>
Date:   Tue, 5 Jan 2021 22:07:10 +0100
Message-ID: <CAHpGcMKfjSddqj7FuUhR00GY+B4Qkzc=bHMVCk4UYQsWeMkxMw@mail.gmail.com>
Subject: Re: [PATCH v2] fs: amend SLAB_RECLAIM_ACCOUNT on gfs2 related slab cache
To:     Bob Peterson <rpeterso@redhat.com>
Cc:     Huangzhaoyang <huangzhaoyang@gmail.com>,
        Andreas Gruenbacher <agruenba@redhat.com>,
        cluster-devel <cluster-devel@redhat.com>,
        Zhaoyang Huang <zhaoyang.huang@unisoc.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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Bob,

Am Di., 5. Jan. 2021 um 14:28 Uhr schrieb Bob Peterson <rpeterso@redhat.com>:
> ----- Original Message -----
> > From: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> >
> > As gfs2_quotad_cachep and gfs2_glock_cachep have registered
> > the shrinker, amending SLAB_RECLAIM_ACCOUNT when creating
> > them, which make the slab acount to be presiced.
> >
> > Signed-off-by: Zhaoyang Huang <zhaoyang.huang@unisoc.com>
> > ---
> > v2: add gfs2_glock_cachep for same operation
> > ---
> Hi,
>
> Thanks. Your patch is now pushed to the linux-gfs2/for-next branch.
> I cleaned up the description a bit. For example, I changed "fs:" to
> "gfs2:" to conform to other gfs2 patches.

so the patch description now reads:

"As gfs2_quotad_cachep and gfs2_glock_cachep have registered
shrinkers, amending SLAB_RECLAIM_ACCOUNT when creating them,
which improves slab accounting."

I'm not sure what that description is based on; the definition of
SLAB_RECLAIM_ACCOUNT in include/linux/slab.h looks as follows, which
indicates that the purpose isn't really accounting but object
grouping:

/* The following flags affect the page allocator grouping pages by mobility */
/* Objects are reclaimable */
#define SLAB_RECLAIM_ACCOUNT    ((slab_flags_t __force)0x00020000U)
#define SLAB_TEMPORARY          SLAB_RECLAIM_ACCOUNT    /* Objects are
short-lived */

Furthermore, would it make sense to use SLAB_RECLAIM_ACCOUNT or
SLAB_TEMPORARY for gfs2_bufdata and gfs2_trans as well?

Thanks,
Andreas