From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: From: Alexander Stein To: Guenter Roeck Cc: linux-watchdog@vger.kernel.org Subject: Re: watchdog timeout in sub-seconds? Date: Tue, 14 Apr 2015 10:15:44 +0200 Message-ID: <4398543.5EAQg64u7T@ws-stein> In-Reply-To: <552BCA3E.5010305@roeck-us.net> References: <3042537.C3OUI66IzY@ws-stein> <552BCA3E.5010305@roeck-us.net> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" List-ID: On Monday 13 April 2015 06:53:02, Guenter Roeck wrote: > On 04/13/2015 06:33 AM, Alexander Stein wrote: > > Hi, > > > > is there a specific reason that the timeout in the linux watchdog drivers is > > only provided in seconds resolution? What about timeouts in ms area/precision? > > > > The question would probably be why not. On a loaded system, sub-second > watchdog timeouts are quite unreasonable. > > In other words, you would have to provide a very good argument for > sub-second timeouts if you see the need for it. That some hardware > may require it is not really an argument here - this is all about > user space - kernel interface, not about limitations of specific > hardware. Well, after discussing this a bit why the hardware watchdog has ms resolution support it turns out this is mainly for safety related devices which seem to require such short timeouts. It doesn't seem to be required on this linux based board though. So this issue has been cleared itself. Best regards, Alexander -- Dipl.-Inf. Alexander Stein SYS TEC electronic GmbH Am Windrad 2 08468 Heinsdorfergrund Tel.: 03765 38600-1156 Fax: 03765 38600-4100 Email: alexander.stein@systec-electronic.com Website: www.systec-electronic.com Managing Director: Dipl.-Phys. Siegmar Schmidt Commercial registry: Amtsgericht Chemnitz, HRB 28082