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 60ACEC2BBCA for ; Tue, 25 Jun 2024 14:08:26 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E84076B02D4; Tue, 25 Jun 2024 10:08:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E33906B02D5; Tue, 25 Jun 2024 10:08:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D225C6B02D6; Tue, 25 Jun 2024 10:08:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id B37AA6B02D4 for ; Tue, 25 Jun 2024 10:08:25 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 61746161A4C for ; Tue, 25 Jun 2024 14:08:25 +0000 (UTC) X-FDA: 82269590970.03.CD7F2AB Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf15.hostedemail.com (Postfix) with ESMTP id 9E978A0028 for ; Tue, 25 Jun 2024 14:08:23 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=none; spf=pass (imf15.hostedemail.com: domain of "SRS0=txrS=N3=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=txrS=N3=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1719324496; a=rsa-sha256; cv=none; b=Yoi6ukLIL1KcHQGm0OrFBoqsAc0FssDXteC9uNTOzzvUcpuArqZMRwZKJXuEgC2TtKSPev vX31jsTiCvJqwaoGO8dqigfKfDsTZP1orWeCMclu2tiqXUZD+xWVSrwzF2FGdF3Mu9qTKx G1ELfp/+DzFQulCAVqYx5C/8OnxzJy4= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=none; spf=pass (imf15.hostedemail.com: domain of "SRS0=txrS=N3=goodmis.org=rostedt@kernel.org" designates 139.178.84.217 as permitted sender) smtp.mailfrom="SRS0=txrS=N3=goodmis.org=rostedt@kernel.org"; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1719324496; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=k24fAeSMI0THC9TP1NtrcjVbUiMsx5Xsp8hmNxG4tPk=; b=Qe4X5y7w3hzBLtdDxzOq8t/EKiQpnUFKzAT6VkZL29tciOvxdTJ9N19GzE1u6eubVsr54D kDBgrGyDI13S2JlDorraMjgQ5U8WfJ24/KeZ9FeYrbKNdYUC94mNX0Xd6oKdlkoK5dm7T9 kzXwY7R9AQzRH9nnRLbRjs13GyrYpZY= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id A18CF61462; Tue, 25 Jun 2024 14:08:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2768DC32781; Tue, 25 Jun 2024 14:08:19 +0000 (UTC) Date: Tue, 25 Jun 2024 10:08:17 -0400 From: Steven Rostedt To: Vlastimil Babka Cc: Akinobu Mita , Christoph Lameter , David Rientjes , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , Masami Hiramatsu , Mark Rutland , Jiri Olsa , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/7] fault-inject: add support for static keys around fault injection sites Message-ID: <20240625100817.078318bf@rorschach.local.home> In-Reply-To: <20240620-fault-injection-statickeys-v2-1-e23947d3d84b@suse.cz> References: <20240620-fault-injection-statickeys-v2-0-e23947d3d84b@suse.cz> <20240620-fault-injection-statickeys-v2-1-e23947d3d84b@suse.cz> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: c5y7wupp5j4qqsp5sn8j1kmfrywsje8j X-Rspamd-Queue-Id: 9E978A0028 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1719324503-39788 X-HE-Meta: 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 8Biv9qtB GB7mZeai1UG7XUlbbFZoQI8cj1PNR3b27He7S9Xws/+LrmP1kWRXecFo+Jitcm665uGji87pRIVviTwq/ouSZmXvcKc1gmpsV7lged+KwNCgLZoCRlGm93B9SteuRdKxfs2wQiAVfJCgKGR8OkqLSWm8vLDjrSdNmqZnJHZIK/+OGs8csKaAIl1MbvJnbaU00waU8808+cC+4DsFnPvnFoGozhItLtzZiGyKNUYP9FB4nnxYJua7r5YYDvOyuKiZRckkcDG0WBP34p40y9RJDtpV8o5+7xbP43QUF8fUbGNsGI+OMtFqnVpyEggW8M55rItHm 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: List-Subscribe: List-Unsubscribe: On Thu, 20 Jun 2024 00:48:55 +0200 Vlastimil Babka wrote: > +static int debugfs_prob_set(void *data, u64 val) > +{ > + struct fault_attr *attr = data; > + > + mutex_lock(&probability_mutex); > + > + if (attr->active) { > + if (attr->probability != 0 && val == 0) { > + static_key_slow_dec(attr->active); > + } else if (attr->probability == 0 && val != 0) { > + static_key_slow_inc(attr->active); > + } > + } So basically the above is testing if val to probability is going from zero or non-zero. For such cases, I find it less confusing to have: if (attr->active) { if (!!attr->probability != !!val) { if (val) static_key_slow_inc(attr->active); else static_key_slow_dec(attr->active); } } This does add a layer of nested ifs, but IMO it's a bit more clear in what is happening, and it gets rid of the "else if". Not saying you need to change it. This is more of an FYI. -- Steve > + > + attr->probability = val; > + > + mutex_unlock(&probability_mutex); > + > + return 0; > +}