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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2641C432C0 for ; Mon, 2 Dec 2019 17:14:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 505D020865 for ; Mon, 2 Dec 2019 17:14:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 505D020865 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E28CC6B0005; Mon, 2 Dec 2019 12:14:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DD91E6B0008; Mon, 2 Dec 2019 12:14:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC7DA6B000A; Mon, 2 Dec 2019 12:14:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0047.hostedemail.com [216.40.44.47]) by kanga.kvack.org (Postfix) with ESMTP id B560E6B0005 for ; Mon, 2 Dec 2019 12:14:19 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 7BE5A181AEF09 for ; Mon, 2 Dec 2019 17:14:19 +0000 (UTC) X-FDA: 76220849838.07.screw03_7d08d77cab028 X-HE-Tag: screw03_7d08d77cab028 X-Filterd-Recvd-Size: 2627 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf08.hostedemail.com (Postfix) with ESMTP for ; Mon, 2 Dec 2019 17:14:19 +0000 (UTC) Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BFE8220848; Mon, 2 Dec 2019 17:14:16 +0000 (UTC) Date: Mon, 2 Dec 2019 12:14:15 -0500 From: Steven Rostedt To: akpm@linux-foundation.org Cc: aneesh.kumar@linux.ibm.com, carmenjackson@google.com, dan.j.williams@intel.com, dancol@google.com, jglisse@redhat.com, joel@joelfernandes.org, linux-mm@kvack.org, mayankgupta@google.com, mhocko@suse.com, minchan@kernel.org, mm-commits@vger.kernel.org, rcampbell@nvidia.com, timmurray@google.com, torvalds@linux-foundation.org, vbabka@suse.cz, willy@infradead.org Subject: Re: [patch 026/158] mm: emit tracepoint when RSS changes Message-ID: <20191202121415.1e64a461@gandalf.local.home> In-Reply-To: <20191201015030.MR-ux4mV1%akpm@linux-foundation.org> References: <20191201015030.MR-ux4mV1%akpm@linux-foundation.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 Sat, 30 Nov 2019 17:50:30 -0800 akpm@linux-foundation.org wrote: > /* Optimized variant when page is already known not to be PageAnon */ > --- a/include/trace/events/kmem.h~mm-emit-tracepoint-when-rss-changes > +++ a/include/trace/events/kmem.h > @@ -316,6 +316,27 @@ TRACE_EVENT(mm_page_alloc_extfrag, > __entry->change_ownership) > ); > > +TRACE_EVENT(rss_stat, > + > + TP_PROTO(int member, > + long count), > + > + TP_ARGS(member, count), > + > + TP_STRUCT__entry( > + __field(int, member) > + __field(long, size) > + ), > + > + TP_fast_assign( > + __entry->member = member; > + __entry->size = (count << PAGE_SHIFT); It's best to put all calculations (including shifts) in the print part, as that's the slow path. The TP_fast_assign() is done when the trace point is triggered (during the execution of the code). It's best to keep this in the slow path (TP_printk). __entry->count = count; > + ), > + > + TP_printk("member=%d size=%ldB", > + __entry->member, > + __entry->size) __entry->count << PAGE_SHIFT) -- Steve > + ); > #endif /* _TRACE_KMEM_H */ > > /* This part must be outside protection */ > --- a/mm/memory.c~mm-emit-tracepoint-when-rss-changes