From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: linux-next: add utrace tree Date: Tue, 26 Jan 2010 23:03:01 +0100 Message-ID: <20100126220301.GG6567@basil.fritz.box> References: <20100122221348.GA4263@redhat.com> <877hr4g49l.fsf@basil.nowhere.org> <20100126210232.GF6567@basil.fritz.box> <20100126215349.GB19146@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20100126215349.GB19146@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Oleg Nesterov Cc: Andi Kleen , Linus Torvalds , tromey@redhat.com, Stephen Rothwell , Kyle Moffett , Peter Zijlstra , Peter Zijlstra , Fr??d??ric Weisbecker , Steven Rostedt , LKML , Arnaldo Carvalho de Melo , "Frank Ch. Eigler" , linux-next@vger.kernel.org, "H. Peter Anvin" , utrace-devel@redhat.com, Thomas Gleixner List-Id: linux-next.vger.kernel.org > Simple example. Try to debug/strace strace ot gdb itself. Not trivial, > you can't attach to strace's tracees. Recently I spent 2 days trying to > understand why strace -f hangs. I was able to attach to strace, but > I wasn't able to see what its tracees do. But what would the semantics be inside the tracees even if you could? > And, it was not possible to even trace strace until it hangs, with > ptrace the tracee (strace) must stop to report the event and this > shadowed the race. "Shadowing the race" was the second surname of strace I thought anyways @) Basically if you care about races never use strace in the first place. -Andi -- ak@linux.intel.com -- Speaking for myself only.