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Mon, 05 Sep 2022 06:00:31 -0700 (PDT) Date: Mon, 5 Sep 2022 15:00:24 +0200 From: Marco Elver To: Oscar Salvador Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Vlastimil Babka , Eric Dumazet , Waiman Long , Suren Baghdasaryan , Andrey Konovalov , Alexander Potapenko Subject: Re: [PATCH v2 2/3] mm, page_owner: Add page_owner_stacks file to print out only stacks and their counter Message-ID: References: <20220905031012.4450-1-osalvador@suse.de> <20220905031012.4450-3-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.6 (2022-06-05) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662382833; a=rsa-sha256; cv=none; b=f+C2jcQy/TsW6RHcLjlyaRpspOXfcdPw/MSEVTlszlDM1xG+FofunxNfuhZ9QCRJGnDx/G SCahGeVEDsPbDfuVqun5Lso8ZW5bXrrELPS2DuojQB7s01etJ6oEsq4snWO3CJbleR00tk isFq6GlKJ0zRzc+g44/5cF6y5wZq/M8= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="on/CTDUc"; 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dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam01 X-Rspam-User: X-Stat-Signature: 3fypbmqw1pzy7w1jmak3c9w7c8ubpq85 X-Rspamd-Queue-Id: 166E4C006A X-HE-Tag: 1662382832-260703 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 05, 2022 at 02:57PM +0200, Marco Elver wrote: [...] > > +{ > > + int i = *pos, ret = 0; > > + struct stack_record **stacks, *stack; > > + static struct stack_record *last = NULL; > > + unsigned long stack_table_entries = stack_hash_mask + 1; > > + > > + /* Continue from the last stack if we have one */ > > + if (last) { > > + stack = last->next; > > This is dead code? Oof, I just noticed that 'last' is static. Please avoid that, because it'll make this interface really tricky to use safely. I still don't quite understand why it needs to do this, and a kernel-doc comment would make this clearer.