linux-kernel - Re: [PATCH] mm/slub: disable slab merging in the default configuration

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Message-ID: <fa76dfe5-c9b8-d24b-89a7-2f906e2b1caa@os.amperecomputing.com>
Date:   Thu, 6 Jul 2023 11:27:06 -0700 (PDT)
From:   "Lameter, Christopher" <cl@...amperecomputing.com>
To:     Christoph Hellwig <hch@...radead.org>
cc:     Julian Pidancet <julian.pidancet@...cle.com>,
        Pekka Enberg <penberg@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Roman Gushchin <roman.gushchin@...ux.dev>,
        Hyeonggon Yoo <42.hyeyoo@...il.com>, linux-mm@...ck.org,
        Jonathan Corbet <corbet@....net>, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, Matthew Wilcox <willy@...radead.org>,
        Kees Cook <keescook@...omium.org>,
        Rafael Aquini <aquini@...hat.com>
Subject: Re: [PATCH] mm/slub: disable slab merging in the default
 configuration

On Thu, 6 Jul 2023, Christoph Hellwig wrote:

> The slab merging has always been bothering me as it makes debugging
> things really hard.  I agree with the other comments on improving
> the commit log, but with that:

Debugging is enabled by specifying "slub_debug" on the kernel command line 
which disables merging and also enables checks so that data corruption 
does trigger meaningful messages for debugging.

Without that you may see errors coming from the slab subsystem that are 
due to data corruption by various subsystems. Without that it will be 
difficult to properly attribute errors anyways.