linux-kernel - Re: [RESEND PATCH] slab: skip kmemleak_object in leaks

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Message-ID: <alpine.DEB.2.21.1905201017420.96074@chino.kir.corp.google.com>
Date:   Mon, 20 May 2019 10:18:05 -0700 (PDT)
From:   David Rientjes <rientjes@...gle.com>
To:     Qian Cai <cai@....pw>
cc:     akpm@...ux-foundation.org, cl@...ux.com, penberg@...nel.org,
        iamjoonsoo.kim@....com, catalin.marinas@....com,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [RESEND PATCH] slab: skip kmemleak_object in leaks_show()

On Tue, 14 May 2019, Qian Cai wrote:

> Running tests on a debug kernel will usually generate a large number of
> kmemleak objects.
> 
>   # grep kmemleak /proc/slabinfo
>   kmemleak_object   2243606 3436210 ...
> 
> As the result, reading /proc/slab_allocators could easily loop forever
> while processing the kmemleak_object cache and any additional freeing or
> allocating objects will trigger a reprocessing. To make a situation
> worse, soft-lockups could easily happen in this sitatuion which will
> call printk() to allocate more kmemleak objects to guarantee a livelock.
> 
> Since kmemleak_object has a single call site (create_object()), there
> isn't much new information compared with slabinfo. Just skip it.
> 
> Signed-off-by: Qian Cai <cai@....pw>

I assume this is now obsolete since commit 7878c231dae0 ("slab: remove 
/proc/slab_allocators").