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[2620:137:e000::1:20]) by mx.google.com with ESMTP id hb20-20020a170907161400b0073da6628a3esi13466011ejc.682.2022.09.01.01.07.31; Thu, 01 Sep 2022 01:07:56 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=CRTVAsmA; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233472AbiIAHGn (ORCPT + 99 others); Thu, 1 Sep 2022 03:06:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233601AbiIAHGJ (ORCPT ); Thu, 1 Sep 2022 03:06:09 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E88F7A9252; Thu, 1 Sep 2022 00:05:38 -0700 (PDT) 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=PMcMlRof4aBmW9ZRc+eOO/2dgQwguo+jd6/zOIwkXz4=; b=CRTVAsmAK2cWYW898rb6ABFc5M uLACuGzlIMyaVe8YmnHdnMTCzaRgU/yORC/GoxdMYsKfSqUkdBcV9CHFquRDxtBp1mrHH1Ek8iUcr mn1JgrUbBdWhUq0dshggnSScCFSCXwzSSm1KuWPF7x5mOnsP+VDfpzlLoRknLlMRFYgTP9KQNHlgH CH7qbZF+ZmtxkOzs27I6vkqhMH23AuEUp5/xcLcIfVX3lpAkPrSHOObJikPLlUvDymQfq9PPQJW2d ahsXPS2phTb5F2Rtarg5EDnzM/T3m8B4GVcztEaB4FRglzTR7JDiDhZuuZYYAbZtb5/Iw4ZAPbP6X Wmout+LA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1oTeGf-005oq2-M2; Thu, 01 Sep 2022 07:05:37 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 2996330010B; Thu, 1 Sep 2022 09:05:36 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 110AE20981381; Thu, 1 Sep 2022 09:05:36 +0200 (CEST) Date: Thu, 1 Sep 2022 09:05:35 +0200 From: Peter Zijlstra To: Kent Overstreet Cc: Mel Gorman , Suren Baghdasaryan , akpm@linux-foundation.org, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, roman.gushchin@linux.dev, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, void@manifault.com, juri.lelli@redhat.com, ldufour@linux.ibm.com, peterx@redhat.com, david@redhat.com, axboe@kernel.dk, mcgrof@kernel.org, masahiroy@kernel.org, nathan@kernel.org, changbin.du@intel.com, ytcoode@gmail.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, bristot@redhat.com, vschneid@redhat.com, cl@linux.com, penberg@kernel.org, iamjoonsoo.kim@lge.com, 42.hyeyoo@gmail.com, glider@google.com, elver@google.com, dvyukov@google.com, shakeelb@google.com, songmuchun@bytedance.com, arnd@arndb.de, jbaron@akamai.com, rientjes@google.com, minchan@google.com, kaleshsingh@google.com, kernel-team@android.com, linux-mm@kvack.org, iommu@lists.linux.dev, kasan-dev@googlegroups.com, io-uring@vger.kernel.org, linux-arch@vger.kernel.org, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 00/30] Code tagging framework and applications Message-ID: References: <20220830214919.53220-1-surenb@google.com> <20220831084230.3ti3vitrzhzsu3fs@moria.home.lan> <20220831101948.f3etturccmp5ovkl@suse.de> <20220831155941.q5umplytbx6offku@moria.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220831155941.q5umplytbx6offku@moria.home.lan> X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 31, 2022 at 11:59:41AM -0400, Kent Overstreet wrote: > Also, ftrace can drop events. Not really ideal if under system load your memory > accounting numbers start to drift. You could attach custom handlers to tracepoints. If you were to replace these unconditional code hooks of yours with tracepoints then you could conditionally (say at boot) register custom handlers that do the accounting you want. Nobody is mandating you use the ftrace ringbuffer to consume tracepoints. Many people these days attach eBPF scripts to them and do whatever they want.