Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756129Ab1EXRJe (ORCPT ); Tue, 24 May 2011 13:09:34 -0400 Received: from mail.perches.com ([173.55.12.10]:1962 "EHLO mail.perches.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755631Ab1EXRJd (ORCPT ); Tue, 24 May 2011 13:09:33 -0400 Subject: Re: [PATCH] drivers: Use kzalloc instead of 'kmalloc+memset', where possible. From: Joe Perches To: Rakib Mullick Cc: linux-kernel@vger.kernel.org, Andrew Morton In-Reply-To: References: <1306172407.8198.3.camel@localhost.localdomain> <1306173085.8687.38.camel@Joe-Laptop> Content-Type: text/plain; charset="UTF-8" Date: Tue, 24 May 2011 10:09:31 -0700 Message-ID: <1306256971.2298.37.camel@Joe-Laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1432 Lines: 33 On Tue, 2011-05-24 at 22:59 +0600, Rakib Mullick wrote: > On 5/23/11, Joe Perches wrote: > > On Mon, 2011-05-23 at 23:40 +0600, Rakib Mullick wrote: > >> Following patch removes the uses of 'kmalloc+memset' from various > >> drivers subsystems, which is replaced by kzalloc. kzalloc take care of > >> setting allocated memory with null, so it helps to get rid from using > >> memset. > >> diff --git a/drivers/gpu/drm/drm_scatter.c b/drivers/gpu/drm/drm_scatter.c > > [] > >> - entry->pagelist = kmalloc(pages * sizeof(*entry->pagelist), GFP_KERNEL); > >> + entry->pagelist = kzalloc(pages * sizeof(*entry->pagelist), GFP_KERNEL); > > Perhaps it's better to use: > > entry->pagelist = kcalloc(pages, sizeof(*entry->pagelist), GFP_KERNEL); > >> - entry->busaddr = kmalloc(pages * sizeof(*entry->busaddr), GFP_KERNEL); > >> + entry->busaddr = kzalloc(pages * sizeof(*entry->busaddr), GFP_KERNEL); > > here too. > Is there any significant benefit of using kcalloc here? Overflow and tradition. static inline void *kcalloc(size_t n, size_t size, gfp_t flags) { if (size != 0 && n > ULONG_MAX / size) return NULL; return __kmalloc(n * size, flags | __GFP_ZERO); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/