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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9473DC433EF for ; Wed, 11 May 2022 12:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242804AbiEKMxL (ORCPT ); Wed, 11 May 2022 08:53:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240793AbiEKMxI (ORCPT ); Wed, 11 May 2022 08:53:08 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 23BEE68308 for ; Wed, 11 May 2022 05:53:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652273586; 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=VWjC9EG18AFZu2LY+9ZGj6V6UHYyFbBc8JjmrNiWDak=; b=i8kIZR1ok+MLIzEQAO9MSEkbZT4f4ODz6ENPtrPhNYxR8DFgNVFQnRS7v9glNDrKZvypdG WsG+VjXvlFAfHC54RZl4WXac07gVD8UkIGYRB1KK8jHrQL09hrZLtiH99dS0+7w+A2GKbe xIDFlSnmAPp1yTYFQtAfDFgpyPfHgCs= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-210-oyQjpJ-DOCmZsnp7SY3unw-1; Wed, 11 May 2022 08:53:05 -0400 X-MC-Unique: oyQjpJ-DOCmZsnp7SY3unw-1 Received: by mail-wm1-f71.google.com with SMTP id m26-20020a7bcb9a000000b0039455e871b6so667875wmi.8 for ; Wed, 11 May 2022 05:53:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=VWjC9EG18AFZu2LY+9ZGj6V6UHYyFbBc8JjmrNiWDak=; b=ntfEa+Z5l5SGdOwO9HLD/gDsPJZbitMdaaVZ4pZ7HU6q3f2hVB/UMoRdALj1j2C2HG J4dQZm+4IKVJYDqUbTz/Ryun1MSIwxxUyuOwZezeQteu71IDWqd+78ktU6tHExRhqtIT hoauwJSYVjcI3fyquxPjvEYKL1Wc3VwIMFXhVs+gpfITatBhQQ9h0c5n8ZXf2ADj6You PjXG0SvyirzooouV5nnNO1+lnHnduVEf3JfYdMH7uOivwGzCr68RV1ODn8J9/cQneq4R J8y5uW0sdIcqwh72Nc2Evjmo7e8ysWXoMk1K3zIxBqVCk4ekn8yMj39N5VHn5RYCUAhf XLCQ== X-Gm-Message-State: AOAM531ZvfUrn7JHmi+R4R8LODpBSLahaBfc6ojC2+ZUmuX3W7Qk+fth zLF+ftpKp5pLNjPvt6jodrnNqoFCErpCxQpMDyEDpJPJA9EG7qDxXLD40/RuQTxBNOpXlsbEJgU jDzrQ0gxsQsnMkinGINRev3Wr X-Received: by 2002:a05:6000:1809:b0:20a:cafc:fd39 with SMTP id m9-20020a056000180900b0020acafcfd39mr22516835wrh.255.1652273584551; Wed, 11 May 2022 05:53:04 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx+U/vXaQanU8gZEU8cQQaRcMVdpu6Mv5VSuen7ploYodJN7MTJe9l14NKBkawEE8+bN/BcPQ== X-Received: by 2002:a05:6000:1809:b0:20a:cafc:fd39 with SMTP id m9-20020a056000180900b0020acafcfd39mr22516814wrh.255.1652273584338; Wed, 11 May 2022 05:53:04 -0700 (PDT) Received: from vschneid.remote.csb ([185.11.37.247]) by smtp.gmail.com with ESMTPSA id c8-20020adfed88000000b0020c5253d909sm1661854wro.85.2022.05.11.05.53.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 May 2022 05:53:03 -0700 (PDT) From: Valentin Schneider To: Yajun Deng , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com Cc: linux-kernel@vger.kernel.org, Yajun Deng Subject: Re: [PATCH] sched/rt: fix the case where sched_rt_period_us is non-positive In-Reply-To: <20220511112140.103579-1-yajun.deng@linux.dev> References: <20220511112140.103579-1-yajun.deng@linux.dev> Date: Wed, 11 May 2022 13:53:03 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/05/22 19:21, Yajun Deng wrote: > The proc_dointvec() in sched_rt_handler() is for integer, but > sysctl_sched_rt_period is a unsigned integer. sched_rt_handler() would > cover a non-positive number to positive number, so both proc_dointvec() > and sched_rt_global_validate() aren't return error when we set a > non-positive number. > > Use proc_dointvec_minmax() instead of proc_dointvec(), and add extra > for sched_rt_period_us/sched_rt_runtime_us/sched_rr_timeslice_ms. > > Fixes: 391e43da797a ("sched: Move all scheduler bits into kernel/sched/") > Signed-off-by: Yajun Deng > --- > kernel/sched/rt.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index b491a0f8c25d..f20389aa6731 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -37,6 +37,7 @@ static struct ctl_table sched_rt_sysctls[] = { > .maxlen = sizeof(unsigned int), > .mode = 0644, > .proc_handler = sched_rt_handler, > + .extra1 = SYSCTL_ONE, > }, Err, what kernel is this based on? AFAICT those have always lived in kernel/sysctl.c, not kernel/sched/rt.c > { > .procname = "sched_rt_runtime_us", > @@ -44,6 +45,8 @@ static struct ctl_table sched_rt_sysctls[] = { > .maxlen = sizeof(int), > .mode = 0644, > .proc_handler = sched_rt_handler, > + .extra1 = SYSCTL_NEG_ONE, > + .extra2 = (void *)&sysctl_sched_rt_period, > }, > { > .procname = "sched_rr_timeslice_ms", > @@ -51,6 +54,7 @@ static struct ctl_table sched_rt_sysctls[] = { > .maxlen = sizeof(int), > .mode = 0644, > .proc_handler = sched_rr_handler, > + .extra1 = SYSCTL_ONE, Per upstream state of sched_rr_handler: * Also, writing zero resets the timeslice to default: which doesn't happen with that new constraint. > }, > {} > }; > @@ -2959,9 +2963,6 @@ static int sched_rt_global_constraints(void) > #ifdef CONFIG_SYSCTL > static int sched_rt_global_validate(void) > { > - if (sysctl_sched_rt_period <= 0) > - return -EINVAL; > - > if ((sysctl_sched_rt_runtime != RUNTIME_INF) && > ((sysctl_sched_rt_runtime > sysctl_sched_rt_period) || > ((u64)sysctl_sched_rt_runtime * > @@ -2992,7 +2993,7 @@ static int sched_rt_handler(struct ctl_table *table, int write, void *buffer, > old_period = sysctl_sched_rt_period; > old_runtime = sysctl_sched_rt_runtime; > > - ret = proc_dointvec(table, write, buffer, lenp, ppos); > + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); > > if (!ret && write) { > ret = sched_rt_global_validate(); > @@ -3027,14 +3028,13 @@ static int sched_rr_handler(struct ctl_table *table, int write, void *buffer, > static DEFINE_MUTEX(mutex); > > mutex_lock(&mutex); > - ret = proc_dointvec(table, write, buffer, lenp, ppos); > + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); > /* > * Make sure that internally we keep jiffies. > * Also, writing zero resets the timeslice to default: > */ > if (!ret && write) { > sched_rr_timeslice = > - sysctl_sched_rr_timeslice <= 0 ? RR_TIMESLICE : > msecs_to_jiffies(sysctl_sched_rr_timeslice); > } > mutex_unlock(&mutex); > -- > 2.25.1