From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754727Ab1CJAgh (ORCPT ); Wed, 9 Mar 2011 19:36:37 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:60149 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754563Ab1CJAge convert rfc822-to-8bit (ORCPT ); Wed, 9 Mar 2011 19:36:34 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=vrfy.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=b8dVwLs66po3XfIRsE25PHYLljUgWnZp2QegWE2PMyxf0NubtTKu+rDPGPsC0wxyK8 UrwPJ2qe4/88lWqTXBOhE4IXJ/I93xY8xtluj9WCisu4wNo/QMurJtR9MsH0qFhbwUBy aBAWHVWzCc69hmXVl65z4s15E6QOzTHzW6N38= MIME-Version: 1.0 In-Reply-To: <20110309162513.5058c824.akpm@linux-foundation.org> References: <1299681411-9227-1-git-send-email-virtuoso@slind.org> <20110309162513.5058c824.akpm@linux-foundation.org> From: Kay Sievers Date: Thu, 10 Mar 2011 01:36:18 +0100 Message-ID: Subject: Re: [RFCv4] timerfd: add TFD_NOTIFY_CLOCK_SET to watch for clock changes To: Andrew Morton Cc: Alexander Shishkin , linux-kernel@vger.kernel.org, Ken MacLeod , Shaun Reich , Thomas Gleixner , Alexander Viro , Greg Kroah-Hartman , Feng Tang , Michael Tokarev , Marcelo Tosatti , John Stultz , Chris Friesen , "Kirill A. Shutemov" , Artem Bityutskiy , Davide Libenzi , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, Michael Kerrisk Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 10, 2011 at 01:25, Andrew Morton wrote: > On Wed,  9 Mar 2011 16:36:51 +0200 > Alexander Shishkin wrote: > >> Changes since v3: >>  - changed timerfd_settime() semantics (see below) >> Changes since v2: >>  - replaced sysfs interface with a syscall >>  - added sysctl/procfs handle to set a limit to the number of users >>  - fixed issues pointed out by Greg. >> Changes since v1: >>  - updated against 2.6.36-rc1, >>  - added notification/filtering options, >>  - added Documentation/ABI/sysfs-kernel-time-notify interface description. > It would be helpful to know if the identified users of this feature > actually find it useful and adequate.  I guess the most common > application is the 1,001 desktop clock widgets.  Do you have any > feedback from any of the owners of those? We want it for systemd, to provide cron-like functionality but without the need to stupidly wake up every minute and check the system time for possible jumps. It also sounds useful for a generic resume (after system suspend) notification for applications, which isn't really possible today. Kay From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Subject: Re: [RFCv4] timerfd: add TFD_NOTIFY_CLOCK_SET to watch for clock changes Date: Thu, 10 Mar 2011 01:36:18 +0100 Message-ID: References: <1299681411-9227-1-git-send-email-virtuoso@slind.org> <20110309162513.5058c824.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Alexander Shishkin , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ken MacLeod , Shaun Reich , Thomas Gleixner , Alexander Viro , Greg Kroah-Hartman , Feng Tang , Michael Tokarev , Marcelo Tosatti , John Stultz , Chris Friesen , "Kirill A. Shutemov" , Artem Bityutskiy , Davide Libenzi , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michael Kerrisk To: Andrew Morton Return-path: In-Reply-To: <20110309162513.5058c824.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Mar 10, 2011 at 01:25, Andrew Morton wrote: > On Wed, =C2=A09 Mar 2011 16:36:51 +0200 > Alexander Shishkin wrote: > >> Changes since v3: >> =C2=A0- changed timerfd_settime() semantics (see below) >> Changes since v2: >> =C2=A0- replaced sysfs interface with a syscall >> =C2=A0- added sysctl/procfs handle to set a limit to the number of u= sers >> =C2=A0- fixed issues pointed out by Greg. >> Changes since v1: >> =C2=A0- updated against 2.6.36-rc1, >> =C2=A0- added notification/filtering options, >> =C2=A0- added Documentation/ABI/sysfs-kernel-time-notify interface d= escription. > It would be helpful to know if the identified users of this feature > actually find it useful and adequate. =C2=A0I guess the most common > application is the 1,001 desktop clock widgets. =C2=A0Do you have any > feedback from any of the owners of those? We want it for systemd, to provide cron-like functionality but without the need to stupidly wake up every minute and check the system time for possible jumps. It also sounds useful for a generic resume (after system suspend) notification for applications, which isn't really possible today. Kay