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[209.85.220.65]) by mx.google.com with SMTPS id v22sor10594721pgb.31.2019.05.07.14.04.46 for (Google Transport Security); Tue, 07 May 2019 14:04:47 -0700 (PDT) Received-SPF: pass (google.com: domain of yury.norov@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=KTfyAoLB; spf=pass (google.com: domain of yury.norov@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=yury.norov@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=Tp9MHM6S82XiPQpC6c6jLekBkf9kgfqCZQyGw89KOqE=; b=KTfyAoLB21CgLn4vV+DeWm27Z0NxxbAZXzSaXHMVtSC6cam9l8ioBG5uvVhsSKhamD 5O8P15XSzgMcT/aYJ6UID2M634g4V0M18eMkOog2O/53+5MJUBFoNjUQ9F7KCvtIlc4F B7frY+UwvuCyqkixc99UccY4Q4r/WBFLetyaU1tp/0auaUSzitr5YJbs0NRr/EXsA/jO Qyum4xwKpBUibLnDJd56JqbnQhzMKlTw48Fm+bceoOk5CPJFQlg4L/CGlS/yDMrG3cxg d0npEcAiUhLIsWEerZF+tsXsVCqSY4NIlXXm2r0szlHmhPy19eJTu1TlNSwo9/sG4/Cs +ZSw== X-Google-Smtp-Source: APXvYqzflAmUTQydzxJ4cjPRW0WIecf2bKx2yQBktISYk/b4xLlIZ0c6pxz/B7pjskqQcN+h0MZuiQ== X-Received: by 2002:a65:6496:: with SMTP id e22mr42445689pgv.249.1557263086677; Tue, 07 May 2019 14:04:46 -0700 (PDT) Received: from localhost ([2601:640:2:82fb:19d3:11c4:475e:3daa]) by smtp.gmail.com with ESMTPSA id u66sm5867753pfa.36.2019.05.07.14.04.45 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 May 2019 14:04:45 -0700 (PDT) Date: Tue, 7 May 2019 14:04:44 -0700 From: Yury Norov To: Aaron Tomlin , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Cc: Yury Norov , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/slub: avoid double string traverse in kmem_cache_flags() Message-ID: <20190507210444.GB8935@yury-thinkpad> References: <20190501053111.7950-1-ynorov@marvell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190501053111.7950-1-ynorov@marvell.com> User-Agent: Mutt/1.9.4 (2018-02-28) 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 Tue, Apr 30, 2019 at 10:31:11PM -0700, Yury Norov wrote: > If ',' is not found, kmem_cache_flags() calls strlen() to find the end > of line. We can do it in a single pass using strchrnul(). Ping? > Signed-off-by: Yury Norov > --- > mm/slub.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 4922a0394757..85f90370a293 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1317,9 +1317,7 @@ slab_flags_t kmem_cache_flags(unsigned int object_size, > char *end, *glob; > size_t cmplen; > > - end = strchr(iter, ','); > - if (!end) > - end = iter + strlen(iter); > + end = strchrnul(iter, ','); > > glob = strnchr(iter, end - iter, '*'); > if (glob) > -- > 2.17.1