From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Authentication-Results: smtp.codeaurora.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="q99Vup58" DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org BA9CB60764 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752491AbeFFPEo (ORCPT + 25 others); Wed, 6 Jun 2018 11:04:44 -0400 Received: from mail-yw0-f194.google.com ([209.85.161.194]:35201 "EHLO mail-yw0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752322AbeFFPEm (ORCPT ); Wed, 6 Jun 2018 11:04:42 -0400 X-Google-Smtp-Source: ADUXVKIFe077I1c8/DA/3G+pOIItv+7SshjxWq//VO15PSKH76qIbqVtpwUyS7+kj/JTSnnk7EINWQ== Date: Wed, 6 Jun 2018 08:04:38 -0700 From: Tejun Heo To: Linus Torvalds Cc: Linux Kernel Mailing List , Li Zefan , Johannes Weiner , cgroups Subject: Re: [GIT PULL] cgroup changes for v4.18-rc1 Message-ID: <20180606150438.GM1351649@devbig577.frc2.facebook.com> References: <20180605192157.GG1351649@devbig577.frc2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Linus. On Tue, Jun 05, 2018 at 05:13:55PM -0700, Linus Torvalds wrote: > On Tue, Jun 5, 2018 at 12:22 PM Tejun Heo wrote: > > > > * cgroup uses file modified events to notify certain events. A rate > > limiting mechanism is added. > > This "explanation" didn't really parse for me at all. > > I edited the merge message to something that I think is correct and > made more sense to me. Heh, yeah, yours reads a lot better. Sorry about that. The background is that the mechanism was first added to generate notifications on events like cgroup becoming empty, which is very low frequency. Since then, we've expanded its usage to cover things like memory.high breached events which can be a lot higher frequency. The notification implementation isn't super light weight, so the patch ratelimits the notifications by capping minimum notification interval interval to 10ms. Thanks. -- tejun