From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f71.google.com (mail-lf0-f71.google.com [209.85.215.71]) by kanga.kvack.org (Postfix) with ESMTP id ABBAF6B0069 for ; Fri, 25 Nov 2016 09:34:29 -0500 (EST) Received: by mail-lf0-f71.google.com with SMTP id 98so26827378lfs.0 for ; Fri, 25 Nov 2016 06:34:29 -0800 (PST) Received: from mail-lf0-x243.google.com (mail-lf0-x243.google.com. [2a00:1450:4010:c07::243]) by mx.google.com with ESMTPS id q19si20536640lff.406.2016.11.25.06.34.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 Nov 2016 06:34:28 -0800 (PST) Received: by mail-lf0-x243.google.com with SMTP id 98so3453261lfs.0 for ; Fri, 25 Nov 2016 06:34:28 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <20161103220058.3017148c790b352c0ec521d4@gmail.com> <20161103141404.2bb6b59435e560f0b82c0a18@linux-foundation.org> <20161103151700.73a98155238acff3f3f98e8b@linux-foundation.org> From: Dan Streetman Date: Fri, 25 Nov 2016 09:33:47 -0500 Message-ID: Subject: Re: [PATCH] z3fold: make pages_nr atomic Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Vitaly Wool Cc: Andrew Morton , Linux-MM , LKML On Fri, Nov 4, 2016 at 3:27 AM, Vitaly Wool wrote: > On Thu, Nov 3, 2016 at 11:17 PM, Andrew Morton > wrote: >> On Thu, 3 Nov 2016 22:24:07 +0100 Vitaly Wool wrote: >> >>> On Thu, Nov 3, 2016 at 10:14 PM, Andrew Morton >>> wrote: >>> > On Thu, 3 Nov 2016 22:00:58 +0100 Vitaly Wool wrote: >>> > >>> >> This patch converts pages_nr per-pool counter to atomic64_t. >>> > >>> > Which is slower. >>> > >>> > Presumably there is a reason for making this change. This reason >>> > should be described in the changelog. >>> >>> The reason [which I thought was somewhat obvious :) ] is that there >>> won't be a need to take a per-pool lock to read or modify that >>> counter. >> >> But the patch didn't change the locking. And as far as I can tell, >> neither does "z3fold: extend compaction function". > > Right. I'll come up with the locking rework shortly, but it will be a > RFC so I wanted to send it separately. this is still in mmotm, and it seems the later patches rely on it, so while i agree that the changelog should be clearer about why it's needed, the change itself looks ok. Acked-by: Dan Streetman > > ~vitaly -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org