From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: Re: [PATCH v2] percpu: improve percpu_alloc_percpu event trace Date: Wed, 11 May 2022 08:11:54 +0300 Message-ID: <30a47b4e-7c4b-cd2d-998d-cfaf8d12d342@openvz.org> References: <2b388d09-940e-990f-1f8a-2fdaa9210fa0@openvz.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=openvz-org.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=FsqMLvYhC8qarZmsr+129u+7sKwrIH+JPr+bFWl7+5k=; b=0aG7kU3eWAaKIv/Td9eRJ5q6oW+7HIa6nEf1s1DtvmoURqmTGUjIfod6WyVpZrOLQG edcTzONtr1MlDcl4mYXZXlsIlXhzvwUxwe7+C22rF9/+P8fccOBzqemsYOYv9io4jg/Q ZgiPvF/qI3UxE9/Jabe8hGdEibI51Ou1/0olIozn+yzyLafL/VSUFC/vqkEt/EM112RX JZcFcxwbJrUGmZwAYuNCS4ajsGwlkMVLFLO0ecCSpRxV5PwCaCzILghm/8EO5CELGx8d qxMOR0ACQ4+iZMB4bvvnZ73gAsuc+A36M7mRsYxpGgDt2PYVqARDUdyhG0vim6eZh8WI nPOA== Content-Language: en-US In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" To: Roman Gushchin Cc: Shakeel Butt , Steven Rostedt , Ingo Molnar , kernel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Vlastimil Babka , Michal Hocko , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org On 5/11/22 05:33, Roman Gushchin wrote: > On Fri, May 06, 2022 at 10:29:25PM +0300, Vasily Averin wrote: >> TRACE_EVENT(percpu_alloc_percpu, >> >> - TP_PROTO(bool reserved, bool is_atomic, size_t size, >> - size_t align, void *base_addr, int off, void __percpu *ptr), >> + TP_PROTO(unsigned long call_site, >> + bool reserved, bool is_atomic, size_t size, >> + size_t align, void *base_addr, int off, >> + void __percpu *ptr, size_t bytes_alloc, gfp_t gfp_flags), > > Don't we want to preserve the order and add the call_site at the end? > Trace events are not ABI, but if we don't have a strong reason to break it, > I'd preserve the old order. I checked recent trace patches and found that order changes is acceptable. commit 8c39b8bc82aafcc8dd378bd79c76fac8e8a89c8d Author: David Howells Date: Fri Jan 14 11:44:54 2022 +0000 cachefiles: Make some tracepoint adjustments - TP_printk("o=%08x i=%lx e=%d", - __entry->obj, __entry->ino, __entry->error) + TP_printk("o=%08x dB=%lx B=%lx e=%d", + __entry->obj, __entry->dino, __entry->ino, __entry->error) On the other hand I'm agree to keep old order by default. that's why I added bytes_alloc and gfp_flags to end of output. However I think call_site is an exception. In all cases found, call_site is output first. For me personally it simplified output parsing. So I would like to know Steven's position on this question. Thank you, Vasily Averin