From mboxrd@z Thu Jan 1 00:00:00 1970 References: From: Philippe Gerum Subject: Re: domain switch In-reply-to: Date: Sun, 03 Jan 2021 11:31:34 +0100 Message-ID: <87zh1qqpkp.fsf@xenomai.org> MIME-Version: 1.0 Content-Type: text/plain List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: steve freyder Cc: Leandro Bucci , xenomai@xenomai.org steve freyder via Xenomai writes: > Right. > > > AKA, "mode switch", a switch from "primary mode" to "secondary mode", > or vice versa. > > One place you can find that information is in: > > /proc/xenomai/sched/acct > > there are two fields MSW, and CSW which count mode/context switches > per-process. This requires an open, a read loop to locate the desired > pid and extract the desired information, then either rewind or > close/reopen to do it again - all of which will almost surely generate > more mode/context switching. > If that helps, there is also the option of getting the thread stats by program, using int cobalt_thread_stat(pid_t pid, struct cobalt_threadstat *stat), declared in sys/cobalt.h. pid refers to a thread identifier (as obtained from gettid(2) in the context of the target thread). It must refer to a Cobalt thread, otherwise the call would fail with -ESRCH. The mode switch count is present in the returned information block (->msw). cobalt_thread_stat() would not cause any mode switch. It can be called by any thread regardless of its type (i.e. regular or Cobalt). -- Philippe.