From: Rustam Kovhaev <rkovhaev@gmail.com>
To: Vlastimil Babka <vbabka@suse.cz>, Dave Chinner <david@fromorbit.com>
Cc: djwong@kernel.org, linux-xfs@vger.kernel.org, cl@linux.com,
penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com,
akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, gregkh@linuxfoundation.org,
Al Viro <viro@zeniv.linux.org.uk>,
dvyukov@google.com
Subject: Re: [PATCH] xfs: use kmem_cache_free() for kmem_cache objects
Date: Thu, 30 Sep 2021 17:32:23 -0700 [thread overview]
Message-ID: <YVZXF3mbaW+Pe+Ji@nuc10> (raw)
In-Reply-To: <a9b3cd91-8ee6-a654-b2a8-00c3efb69559@suse.cz>
On Thu, Sep 30, 2021 at 11:10:10PM +0200, Vlastimil Babka wrote:
> On 9/30/21 8:48 PM, Rustam Kovhaev wrote:
> > On Thu, Sep 30, 2021 at 10:13:40AM +0200, Vlastimil Babka wrote:
> >>
> >> I think it's fair if something like XFS (not meant for tiny systems AFAIK?)
> >> excludes SLOB (meant for tiny systems). Clearly nobody tried to use these
> >> two together last 5 years anyway.
> >
> > +1 for adding Kconfig option, it seems like some things are not meant to
> > be together.
>
> But if we patch SLOB, we won't need it.
OK, so we consider XFS on SLOB a supported configuration that might be
used and should be tested.
I'll look into maybe adding a config with CONFIG_SLOB and CONFIG_XFS_FS
to syzbot.
It seems that we need to patch SLOB anyway, because any other code can
hit the very same issue.
> >> Maybe we could also just add the 4 bytes to all SLOB objects, declare
> >> kfree() is always fine and be done with it. Yes, it will make SLOB footprint
> >> somewhat less tiny, but even whan we added kmalloc power of two alignment
> >> guarantees, the impact on SLOB was negligible.
> >
> > I'll send a patch to add a 4-byte header for kmem_cache_alloc()
> > allocations.
>
> Thanks. Please report in the changelog slab usage from /proc/meminfo
> before and after patch (at least a snapshot after a full boot).
OK.
next prev parent reply other threads:[~2021-10-01 0:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 21:23 [PATCH] xfs: use kmem_cache_free() for kmem_cache objects Rustam Kovhaev
2021-09-30 4:42 ` Dave Chinner
2021-09-30 8:13 ` Vlastimil Babka
2021-09-30 18:48 ` Rustam Kovhaev
2021-09-30 21:10 ` Vlastimil Babka
2021-10-01 0:32 ` Rustam Kovhaev [this message]
2021-10-04 1:07 ` David Rientjes
2021-10-12 20:43 ` Darrick J. Wong
2021-10-12 20:43 ` Darrick J. Wong
2021-10-12 21:32 ` Vlastimil Babka
2021-10-12 23:22 ` Darrick J. Wong
2021-10-13 7:38 ` Vlastimil Babka
2021-10-13 16:56 ` Rustam Kovhaev
2021-10-15 0:57 ` Darrick J. Wong
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