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Subject: Re: [PATCH v2] mm/slub: introduce SLAB_WARN_ON_ERROR
From:   Miles Chen <miles.chen@mediatek.com>
To:     David Rientjes <rientjes@google.com>
CC:     Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jonathan Corbet <corbet@lwn.net>, <linux-mm@kvack.org>,
        <linux-kernel@vger.kernel.org>,
        <linux-mediatek@lists.infradead.org>
Date:   Tue, 29 Jan 2019 11:45:57 +0800
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On Mon, 2019-01-28 at 17:41 -0800, David Rientjes wrote:
> On Thu, 24 Jan 2019, miles.chen@mediatek.com wrote:
> 
> > From: Miles Chen <miles.chen@mediatek.com>
> > 
> > When debugging slab errors in slub.c, sometimes we have to trigger
> > a panic in order to get the coredump file. Add a debug option
> > SLAB_WARN_ON_ERROR to toggle WARN_ON() when the option is set.
> > 
> 
> Wouldn't it be better to enable/disable this for all slab caches instead 
> of individual caches at runtime?  I'm not sure excluding some caches 
> because you know they'll WARN and trigger panic_on_warn unnecessarily is 
> valid since it could be enabled for that cache as well through this 
> interface.

We can enable this option only for specific slab(s).
e.g., slub_debug=W,dentry
or
enable this option for all slabs
e.g., slub_debug=W