From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756274AbaEPH5g (ORCPT ); Fri, 16 May 2014 03:57:36 -0400 Received: from mail-ee0-f49.google.com ([74.125.83.49]:57055 "EHLO mail-ee0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755347AbaEPH5e (ORCPT ); Fri, 16 May 2014 03:57:34 -0400 Date: Fri, 16 May 2014 09:57:30 +0200 From: Michal Hocko To: Andrew Morton Cc: Jianyu Zhan , iamjoonsoo.kim@lge.com, aneesh.kumar@linux.vnet.ibm.com, n-horiguchi@ah.jp.nec.com, aarcange@redhat.com, steve.capper@linaro.org, davidlohr@hp.com, kirill.shutemov@linux.intel.com, dave.hansen@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm, hugetlb: move the error handle logic out of normal code path Message-ID: <20140516075730.GA22818@dhcp22.suse.cz> References: <1400051459-20578-1-git-send-email-nasa4836@gmail.com> <20140515090142.GB3938@dhcp22.suse.cz> <20140515153620.344fe054b6b8d054a28fbf82@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140515153620.344fe054b6b8d054a28fbf82@linux-foundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 15-05-14 15:36:20, Andrew Morton wrote: > On Thu, 15 May 2014 11:01:42 +0200 Michal Hocko wrote: > > > On Wed 14-05-14 15:10:59, Jianyu Zhan wrote: > > > alloc_huge_page() now mixes normal code path with error handle logic. > > > This patches move out the error handle logic, to make normal code > > > path more clean and redue code duplicate. > > > > I don't know. Part of the function returns and cleans up on its own and > > other part relies on clean up labels. This is not so much nicer than the > > previous state. > > That's actually a common pattern: > > foo() > { > if (check which doesn't change any state) > return -Efoo; > if (another check which doesn't change any state) > return -Ebar; > > do_something_which_changes_state() > > if (another check) > goto undo_that_state_chage; > ... > > undo_that_state_change: > ... > } Right. I have misread the previous vma_needs_reservation and hugepage_subpool_get_pages error path and already considered it as a changing state one. Sorry about the confusion. -- Michal Hocko SUSE Labs