From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E07CC433EF for ; Wed, 11 May 2022 17:30:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E4D5E6B0075; Wed, 11 May 2022 13:30:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD3706B0074; Wed, 11 May 2022 13:30:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C4E666B0075; Wed, 11 May 2022 13:30:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id B2D656B0073 for ; Wed, 11 May 2022 13:30:46 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 8236D320ED for ; Wed, 11 May 2022 17:30:46 +0000 (UTC) X-FDA: 79454152092.07.9790C4C Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf11.hostedemail.com (Postfix) with ESMTP id D5CCA400AC for ; Wed, 11 May 2022 17:30:40 +0000 (UTC) Date: Wed, 11 May 2022 10:30:37 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1652290243; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hGt3BnCoU4kW+K89I9JK4z3L3KmFUi2s6F9PRzSqJy4=; b=je+mlCfAdY+4OyJgDBp5E3GBVuEBLdvt6J+eoOdJnIYkin2GEDUy3o1Xu4pmthPdnADjnW y1H2V1XbN5Q/fcQSXljhOoimbX3DNpiiDGnDR+z0zWakiPMO6Msv/BaB0DNLnlU7MSn595 ruFFuRlABf7+uSqATZ77rTKjlERBqG0= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Vasily Averin Cc: Shakeel Butt , Steven Rostedt , Ingo Molnar , kernel@openvz.org, linux-kernel@vger.kernel.org, Vlastimil Babka , Michal Hocko , cgroups@vger.kernel.org, Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter , linux-mm@kvack.org Subject: Re: [PATCH v2] percpu: improve percpu_alloc_percpu event trace Message-ID: References: <2b388d09-940e-990f-1f8a-2fdaa9210fa0@openvz.org> <30a47b4e-7c4b-cd2d-998d-cfaf8d12d342@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <30a47b4e-7c4b-cd2d-998d-cfaf8d12d342@openvz.org> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: D5CCA400AC X-Stat-Signature: ihua4dymdij3kkiczhwhku1ftgaqkxkk Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=je+mlCfA; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf11.hostedemail.com: domain of roman.gushchin@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev X-Rspam-User: X-HE-Tag: 1652290240-225289 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, May 11, 2022 at 08:11:54AM +0300, Vasily Averin wrote: > 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. Ok, not a strong opinion, I think both options are acceptable. Thanks!