Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756650AbaDVOTj (ORCPT ); Tue, 22 Apr 2014 10:19:39 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:37302 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756066AbaDVOTf (ORCPT ); Tue, 22 Apr 2014 10:19:35 -0400 MIME-Version: 1.0 In-Reply-To: <535679A4.4050507@kernel.dk> References: <1398144370-9236-1-git-send-email-nasa4836@gmail.com> <535679A4.4050507@kernel.dk> From: Jianyu Zhan Date: Tue, 22 Apr 2014 22:18:55 +0800 Message-ID: Subject: Re: [PATCH] blk-cgroup: explicitly init the early_init field To: Jens Axboe Cc: LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 22, 2014 at 10:16 PM, Jens Axboe wrote: > The rest of the members will be zero-filled by default, so your patch should > not change anything. Hi, Jens I'm sorry I should have made this more clear. Sure, for this global variable struct, if not initailized, its all fields will be initialized to 0 or null(depending on its type). The point here is no to deprive the rights of compiler/linker of doing this initialization, it is mainly for documentation reason. Actually this field's value would affect how ->css_alloc should implemented. Concretely, if early_init is nonzero, then ->css_alloc *must not* call kzalloc, because in cgroup implementation, ->css_alloc will be called earlier before mm_init(). I don't think that the value of one field(early_init) has a so subtle restrition on the another field(css_alloc) is a good thing, but since it is there, docment it should be needed. Thanks, Jianyu Zhan -- 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/