From: Andrew Morton <akpm@linux-foundation.org>
To: <miles.chen@mediatek.com>
Cc: Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
"David Rientjes" <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Jonathan Corbet <corbet@lwn.net>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>
Subject: Re: [PATCH v2] mm/slub: introduce SLAB_WARN_ON_ERROR
Date: Mon, 28 Jan 2019 12:29:54 -0800 [thread overview]
Message-ID: <20190128122954.949c2e6699d6e5ef060a325c@linux-foundation.org> (raw)
In-Reply-To: <1548313223-17114-1-git-send-email-miles.chen@mediatek.com>
On Thu, 24 Jan 2019 15:00:23 +0800 <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.
>
> Change since v1:
> 1. Add a special debug option SLAB_WARN_ON_ERROR and toggle WARN_ON()
> if it is set.
> 2. SLAB_WARN_ON_ERROR can be set by kernel parameter slub_debug.
>
Hopefully the slab developers will have an opinion on this.
> --- a/Documentation/vm/slub.rst
> +++ b/Documentation/vm/slub.rst
> @@ -52,6 +52,7 @@ Possible debug options are::
> A Toggle failslab filter mark for the cache
> O Switch debugging off for caches that would have
> caused higher minimum slab orders
> + W Toggle WARN_ON() on slab errors
> - Switch all debugging off (useful if the kernel is
> configured with CONFIG_SLUB_DEBUG_ON)
This documentation is poorly phrased. The term "toggle" means to
invert the value of a boolean: if it was 1, make it 0 and if it was 0,
make it 1. But that isn't what these options do. Something like
"enable/disable" would be better. So...
--- a/Documentation/vm/slub.rst~mm-slub-introduce-slab_warn_on_error-fix
+++ a/Documentation/vm/slub.rst
@@ -49,10 +49,10 @@ Possible debug options are::
P Poisoning (object and padding)
U User tracking (free and alloc)
T Trace (please only use on single slabs)
- A Toggle failslab filter mark for the cache
+ A Enable/disable failslab filter mark for the cache
O Switch debugging off for caches that would have
caused higher minimum slab orders
- W Toggle WARN_ON() on slab errors
+ W Enable/disable WARN_ON() on slab errors
- Switch all debugging off (useful if the kernel is
configured with CONFIG_SLUB_DEBUG_ON)
_
next prev parent reply other threads:[~2019-01-28 20:29 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-24 7:00 miles.chen
2019-01-24 7:00 ` miles.chen
2019-01-28 20:29 ` Andrew Morton [this message]
2019-01-29 5:46 ` Christopher Lameter
2019-01-29 7:53 ` Miles Chen
2019-01-29 19:46 ` Christopher Lameter
2019-01-30 1:43 ` Miles Chen
2019-01-29 1:41 ` David Rientjes
2019-01-29 3:45 ` Miles Chen
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