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Message-ID: <c84d6962-34fa-42e5-899c-925579cbfb26@kernel.org>
Date: Tue, 28 May 2024 15:44:51 +0200
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Subject: Re: [PATCH] memcg: Remove the lockdep assert from
 __mod_objcg_mlstate().
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To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeel.butt@linux.dev>,
 Andrew Morton <akpm@linux-foundation.org>,
 Johannes Weiner <hannes@cmpxchg.org>, Michal Hocko <mhocko@kernel.org>,
 Roman Gushchin <roman.gushchin@linux.dev>,
 Muchun Song <muchun.song@linux.dev>, linux-mm@kvack.org,
 linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
References: <20240528121928.i-Gu7Jvg@linutronix.de>
 <09e085bb-f09e-4901-a2dd-a0b789bb8a4d@kernel.org>
 <20240528134027.OxDASsS3@linutronix.de>
From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
In-Reply-To: <20240528134027.OxDASsS3@linutronix.de>
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On 5/28/24 3:40 PM, Sebastian Andrzej Siewior wrote:
> On 2024-05-28 14:34:55 [+0200], Vlastimil Babka (SUSE) wrote:
>> > The safety of the counter update is already ensured by
>> > VM_WARN_ON_IRQS_ENABLED() which is part of memcg_stats_lock() and does
>> > not require yet another check.
>> 
>> I think here it's __mod_memcg_lruvec_state() doing the VM_WARN_ON_ as we
>> don't go through memcg_stats_lock()?
> 
> It is either VM_WARN_ON_IRQS_ENABLED() directly as in
> __mod_memcg_lruvec_state() (which is special) or memcg_stats_lock().
> 
> Do you want me to rephrase this part?

I think just s/memcg_stats_lock()/__mod_memcg_lruvec_state()/ in your
phrasing, since we are removing the lockdep assert from path that calls
__mod_memcg_lruvec_state() and not memcg_stats_lock()?
Or am I missing something?

> Sebastian