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Date:   Thu, 1 Sep 2022 10:38:08 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Marco Elver <elver@google.com>
Cc:     Oscar Salvador <osalvador@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Vlastimil Babka <vbabka@suse.cz>,
        Eric Dumazet <edumazet@google.com>,
        Waiman Long <longman@redhat.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Alexander Potapenko <glider@google.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>, kasan-dev@googlegroups.com
Subject: Re: [PATCH 1/3] lib/stackdepot: Add a refcount field in stack_record
Message-ID: <YxBvcDFSsLqn3i87@dhcp22.suse.cz>
References: <20220901044249.4624-1-osalvador@suse.de>
 <20220901044249.4624-2-osalvador@suse.de>
 <YxBsWu36eqUw03Dy@elver.google.com>
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On Thu 01-09-22 10:24:58, Marco Elver wrote:
> On Thu, Sep 01, 2022 at 06:42AM +0200, Oscar Salvador wrote:
[...]
> > diff --git a/lib/stackdepot.c b/lib/stackdepot.c
> > index 5ca0d086ef4a..aeb59d3557e2 100644
> > --- a/lib/stackdepot.c
> > +++ b/lib/stackdepot.c
> > @@ -63,6 +63,7 @@ struct stack_record {
> >  	u32 hash;			/* Hash in the hastable */
> >  	u32 size;			/* Number of frames in the stack */
> >  	union handle_parts handle;
> > +	refcount_t count;		/* Number of the same repeated stacks */
> 
> This will increase stack_record size for every user, even if they don't
> care about the count.

Couldn't this be used for garbage collection?
-- 
Michal Hocko
SUSE Labs