Date: Wed, 19 Oct 2016 11:18:18 +0000 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: Andriy Gapon <avg@FreeBSD.org> Cc: freebsd-arch@FreeBSD.org Subject: Re: watchdog end-user interface Message-ID: <21377.1476875898@critter.freebsd.dk> In-Reply-To: <ec3dfab5-c3bc-e9e5-181e-8c2704f60acd@FreeBSD.org> References: <ec3dfab5-c3bc-e9e5-181e-8c2704f60acd@FreeBSD.org>
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-------- In message <ec3dfab5-c3bc-e9e5-181e-8c2704f60acd@FreeBSD.org>, Andriy Gapo= n wri tes: >I want to question if those options really belong to watchdogd. >When a watchdog timer expires that results in a system-wide action (like = a >system reset). To me, that implies that there should be a single system-= wide >configuration point. And I am not sure that the daemon is the best choic= e for it. The reason I originally put it in a daemon, was to have the watchdog implicitly test the kernels ability to schedule trivial processes. It used to be, and may still be so that, there are deadlocks where the kernel was twiddling its thumbs but userland did not progress. Typical triggers for this are disk-I/O errors, corrupt filesystems, memory overcommit etc. A kernel-only watchdog patter would not trigger in that case. -- = Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe = Never attribute to malice what can adequately be explained by incompetence= .
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