From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA25E23FC5A for ; Fri, 2 May 2025 11:11:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746184295; cv=none; b=DMBcuhrIu6EKummQi/ClI+OvBjaQFwGbV1mV5aGw5FlTDY3um93v/1f3/WCtNSKQfmg2jumf+EK3kDXllCTIEne8NL8vKr9dkWJ7BtNNw+k9M4Abnn3Q0ZwLPy1ktzqkRn3Xx8U/tP8gYnAUxrjux8aGXGoutDdqDJop9qee4OQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746184295; c=relaxed/simple; bh=lxjGHS3cfRSQaQe4SoSD/hzcMZPlcMfBcwBXxPqcwQ8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uN212A/jIFzcUUQMC3Fg9al/LO/oLLhiTJfp42kOscLlgszzR0zv0AWPfPuQ6Vz3y424evhuhw2eVzeaSCu8Fuu8vFZIRNP4ln7/zaq1O0nNFxnblPiT0q5FH1i4e5rYLlMYSZmdl5ec9PSeJmhRo6/LuVkDB0g4sMkHHEK1VLY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=UaWPp5Fu; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="UaWPp5Fu" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=rOcmUHivWm2VyijzsBx2fgbFNnH4PTajNysnSptcXWo=; b=UaWPp5FubR6G8XSifKUH5oHEqv 5FWN3MCNRlpz4lbl9v7mMT73rlWRj/zO98rUPFdgD6OiHRLwTJ/hwHqU9M6Zan7Ib1r3QT0UnsvKV aYIK+v8giP1CTbM6AIFa66XQVpmY4PecIoapK50uDsN8ZBKlVy4QyRvR21ei25DAcJx7f38NX9LRy GuCcJbEx+48GPuKUqxzhAtBWiGBbZkqv4Edb4lCiqpahu54sCVjbyk3uZ0kWwUwACengc0v1KC6BD T9Ugjf170jcrK/26huMOjF7lZvJdBXVoA8tMUd9byVJFAo6kEjicaJh77gY+ptGQuKdTF3gWkcr7d f2ni50fw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uAoIE-0000000F0w4-1kBh; Fri, 02 May 2025 11:10:59 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 602C030057C; Fri, 2 May 2025 13:10:44 +0200 (CEST) Date: Fri, 2 May 2025 13:10:44 +0200 From: Peter Zijlstra To: Sebastian Andrzej Siewior Cc: Prakash Sangappa , linux-kernel@vger.kernel.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, tglx@linutronix.de, kprateek.nayak@amd.com Subject: Re: [PATCH V3 4/4] Sched: Add tracepoint for sched time slice extension Message-ID: <20250502111044.GY4198@noisy.programming.kicks-ass.net> References: <20250502015955.3146733-1-prakash.sangappa@oracle.com> <20250502015955.3146733-5-prakash.sangappa@oracle.com> <20250502091434.GV4198@noisy.programming.kicks-ass.net> <20250502110210.rZX1iHcg@linutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250502110210.rZX1iHcg@linutronix.de> On Fri, May 02, 2025 at 01:02:10PM +0200, Sebastian Andrzej Siewior wrote: > On 2025-05-02 11:14:34 [+0200], Peter Zijlstra wrote: > > This is horrific coding style. But really why do we need this? I'm not, > > in general, a fan of tracepoints. > > I suggested a tracepoint so that we see why the NEED_RESCHED flag > disappeared. The trace would show a wakeup, the need_resched flag would > be set and the flag would disappear without an explanation. Would we not see a timer_start event for the hrtick or somesuch?