From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164516AbeBOXRV (ORCPT ); Thu, 15 Feb 2018 18:17:21 -0500 Received: from mail-it0-f68.google.com ([209.85.214.68]:40648 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163785AbeBOXRT (ORCPT ); Thu, 15 Feb 2018 18:17:19 -0500 X-Google-Smtp-Source: AH8x224RsgrP07c7Q5qhZGtpfvLdBeQbU5NWeoZxUenrpMGio2DPXWB5/BnqasDEtLkwfcEyWE4lPg== Date: Thu, 15 Feb 2018 17:17:14 -0600 From: Dennis Zhou To: Tejun Heo Cc: Christoph Lameter , Daniel Borkmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] percpu: allow select gfp to be passed to underlying allocators Message-ID: <20180215231714.GB79973@localhost> References: <20180215214148.GV695913@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180215214148.GV695913@devbig577.frc2.facebook.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Thu, Feb 15, 2018 at 01:41:48PM -0800, Tejun Heo wrote: > On Thu, Feb 15, 2018 at 10:08:16AM -0600, Dennis Zhou wrote: > > +/* the whitelisted flags that can be passed to the backing allocators */ > > +#define gfp_percpu_mask(gfp) (((gfp) & (__GFP_NORETRY | __GFP_NOWARN)) | \ > > + GFP_KERNEL) > > Isn't there just one place where gfp comes in from outside? If so, > this looks like a bit of overkill. Can't we just filter there? > I agree, but it's also nice having a single place where flags can be added or removed. The primary motivator was for the "| GFP_KERNEL", but as suggested in the other patch this is getting removed. I guess I still lean towards having it as it's explicit and helps gate both the balance path and the user allocation path. Thanks, Dennis