From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 6 Apr 2007 21:40:10 +0200 From: Ingo Molnar Subject: Re: preemption and rwsems (was: Re: missing madvise functionality) Message-ID: <20070406194010.GA21322@elte.hu> References: <46128CC2.9090809@redhat.com> <20070403172841.GB23689@one.firstfloor.org> <20070403125903.3e8577f4.akpm@linux-foundation.org> <4612B645.7030902@redhat.com> <20070403202937.GE355@devserv.devel.redhat.com> <19526.1175777338@redhat.com> <20070405191129.GC22092@elte.hu> <20070405133742.88abc4f8.akpm@linux-foundation.org> <20070406090822.GA2425@elte.hu> <20070406123010.802c76b4.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070406123010.802c76b4.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: David Howells , Jakub Jelinek , Ulrich Drepper , Andi Kleen , Rik van Riel , Linux Kernel , linux-mm@kvack.org, Hugh Dickins List-ID: * Andrew Morton wrote: > > i've attached an updated version of trace-it.c, which will turn this > > off itself, using a sysctl. I also made WAKEUP_TIMING default-off. > > ok. http://userweb.kernel.org/~akpm/to-ingo.txt is the trace of > > taskset -c 0 ./jakubs-test-app > > while the system was doing the 150,000 context switches/sec. > > It isn't very interesting. this shows an idle CPU#7: you should taskset -c 0 trace-it too - it only traces the current CPU by default. (there's the /proc/sys/kernel/trace_all_cpus flag to trace all cpus, but in this case we really want the trace of CPU#0) Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org