From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 7EAB121D3F8 for ; Thu, 3 Jul 2025 12:36:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751546208; cv=none; b=C0fAyNRJxXn3UZ6Iq7c557PAY4eQpMeenpKRJOaajUqiDNJkMcOtjAMvTL5nIfDMFFSB75PIzRlesRv/O5Fvn7UnyHhhk++X9lCb8HAKBHM+47PintdJc19F6TErKDy/yV042+Etco5SguykLfUDSWjT/HpWC/yQ+vxhxYL5RWs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751546208; c=relaxed/simple; bh=HecbAPa3rncj39eTzk18tRqZ32VIPiiq0hhgnrl1Ywo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XF0TDX57WeLHPlQrZXshfHvP6U5fPy+BE06UxX4Vhj+CffxC9G8mL93F/dA4/kG5/7sDeZfvYtBQKn4zMwOALuJ0Yqya+DB18A/CWN34Jz+PRWkNL5vZK7vYxFR95gw+sLv7fQDV774JLhnRFUVBAmpEbKr8zzOXETRy5Z9wduw= 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=VhIAhpDt; arc=none smtp.client-ip=90.155.92.199 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="VhIAhpDt" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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=nYpNb66VmDnizjMo0fFecW51iy25oLQuiGDoq0i3Ea4=; b=VhIAhpDtnzEKp9Jb2MXfi6YdGf bL4nk9c/1EEaffJ8Ru3GPMKoLPaV3d7jLB6dR4+sCt0VMVBd6aIDxbB666PAmTjAJ86uwUOeE1hG2 7KgSmyXdq899QCFt1luzjMgwjG5Q+ESHc6v+xQNNBqFuTBFJINU43UZUcyk5rN6BHi8Fmh/roOkO4 xKDBIcscjn7WPzHxBOaR0t2AtZYnW3ZPtSc9BIOgyqdSguAeBPJ7c4rIx1CjDwMipQIPVpRptricg lmMyJKh4NF6gIcQfoyFmTSsP/fAyYtGUfvWjsiTELK+ktGu+BzeXSd7+apu+1UQmmh7/wJ1YaAb2R i6H+MD0A==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uXJAx-00000007gqS-1oTa; Thu, 03 Jul 2025 12:36:27 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4EA0A30017D; Thu, 03 Jul 2025 14:36:26 +0200 (CEST) Date: Thu, 3 Jul 2025 14:36:26 +0200 From: Peter Zijlstra To: Libo Chen Cc: "Chen, Yu C" , Michal Hocko , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Andrew Morton , Tim Chen , linux-kernel@vger.kernel.org, Jirka Hladky , Srikanth Aithal , Suneeth D Subject: Re: [PATCH] sched/numa: Fix NULL pointer access to mm_struct durng task swap Message-ID: <20250703123626.GW1613200@noisy.programming.kicks-ass.net> References: <20250702163247.324439-1-yu.c.chen@intel.com> <20250703072608.GS1613200@noisy.programming.kicks-ass.net> <20250703115006.GT1613200@noisy.programming.kicks-ass.net> 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: On Thu, Jul 03, 2025 at 05:20:47AM -0700, Libo Chen wrote: > I agree. The other parts, schedstat and vmstat, are still quite helpful. > Also tracepoints are more expensive than counters once enabled, I think > that's too much for just counting numbers. I'm not generally a fan of eBPF, but supposedly it is really good for stuff like this. Attaching to a tracepoint and distributing into cgroup buckets seems like it should be a trivial script.