From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEC751BC3F for ; Mon, 19 Aug 2024 02:18:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724033901; cv=none; b=pIneoi+Cxo/2yJEjKpvHbdznk6NsQys+Upyxs+NxGmqirFCOep/gY2j5KvTG8oLPFkkRwW1fb3asgknjroMeMqiPQdElnR3fKQooyspzy82e5s6t5F6iMzMqmyowrGM75XlsQDTHFSnOZDfuKN9NLEtYDqofDbQe6c3w2xXC5Ms= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724033901; c=relaxed/simple; bh=3odVzTPLqDJOmWI//z/O5XNxhyzdCP3ugylcNCVOyvs=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=cYvMcETSiVAK5GTVZOTlmfCXk5Bpn/4Y/Vq4UprQoVq176WLHx7sDu7ndU3cvUgKDORmbTe2HyfEWZ9wvzz+SnY+I0QXprcV0GXi1yN7x1FApOJSZSLrw7O7NEIsUNxqyVsO2hMhKPNZj0tgClPryuJVFirUyDc84MUHgIwQ51k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=F+CXjTTB; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="F+CXjTTB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1724033898; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Zy2n/iSTOmuSOtCCgNALCFYMM/+MYQpcLsQpKWzeBUA=; b=F+CXjTTBH321yoWGkejtDtHlZ0yY0ZC1nn1bpLUsL87yzCj0HHVTbwJzcMQIAYibvgoC/O b3t3osSzibFgRB4kTyFB0qB2ypPCzLHDSC9xRLEDbVyjh8Ey/61hLObEonTU6hSsimRBDZ LmyTtzzV6Z/z6pQHlF/VzXcusuKWhgs= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-448-SYOiRmuIPTq3BpxKxSpbfA-1; Sun, 18 Aug 2024 22:18:13 -0400 X-MC-Unique: SYOiRmuIPTq3BpxKxSpbfA-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 4751D1955BF1; Mon, 19 Aug 2024 02:18:11 +0000 (UTC) Received: from [10.2.16.4] (unknown [10.2.16.4]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 757FB1955F43; Mon, 19 Aug 2024 02:18:09 +0000 (UTC) Message-ID: Date: Sun, 18 Aug 2024 22:18:08 -0400 Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH -next 1/3] cgroup/cpuset: Correct invalid remote parition prs From: Waiman Long To: Chen Ridong , tj@kernel.org, lizefan.x@bytedance.com, hannes@cmpxchg.org, adityakali@google.com, sergeh@kernel.org, mkoutny@suse.com Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org References: <20240816082727.2779-1-chenridong@huawei.com> <20240816082727.2779-2-chenridong@huawei.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 8/18/24 22:14, Waiman Long wrote: > > On 8/16/24 04:27, Chen Ridong wrote: >> When enable a remote partition, I found that: >> >> cd /sys/fs/cgroup/ >> mkdir test >> mkdir test/test1 >> echo +cpuset > cgroup.subtree_control >> echo +cpuset >  test/cgroup.subtree_control >> echo 3 > test/test1/cpuset.cpus >> echo root > test/test1/cpuset.cpus.partition >> cat test/test1/cpuset.cpus.partition >> root invalid (Parent is not a partition root) >> >> The parent of a remote partition could not be a root. This is due to the >> emtpy effective_xcpus. It would be better to prompt the message "invalid >> cpu list in cpuset.cpus.exclusive". >> >> Signed-off-by: Chen Ridong >> --- >>   kernel/cgroup/cpuset.c | 42 +++++++++++++++++++++++------------------- >>   1 file changed, 23 insertions(+), 19 deletions(-) >> >> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c >> index e34fd6108b06..fdd5346616d3 100644 >> --- a/kernel/cgroup/cpuset.c >> +++ b/kernel/cgroup/cpuset.c >> @@ -80,6 +80,7 @@ enum prs_errcode { >>       PERR_HOTPLUG, >>       PERR_CPUSEMPTY, >>       PERR_HKEEPING, >> +    PERR_PMT, One more thing, the "PMT" acronym for the error code is hard to decode. I will suggest you either use the "PERMISSION" or "ACCESS" like the EACCESS errno. Cheers, Longman >>   }; >>     static const char * const perr_strings[] = { >> @@ -91,6 +92,7 @@ static const char * const perr_strings[] = { >>       [PERR_HOTPLUG]   = "No cpu available due to hotplug", >>       [PERR_CPUSEMPTY] = "cpuset.cpus and cpuset.cpus.exclusive are >> empty", >>       [PERR_HKEEPING]  = "partition config conflicts with >> housekeeping setup", >> +    [PERR_PMT]       = "Enable partition not permitted", >>   }; >>     struct cpuset { >> @@ -1669,7 +1671,7 @@ static int remote_partition_enable(struct >> cpuset *cs, int new_prs, >>        * The user must have sysadmin privilege. >>        */ >>       if (!capable(CAP_SYS_ADMIN)) >> -        return 0; >> +        return PERR_PMT; >>         /* >>        * The requested exclusive_cpus must not be allocated to other >> @@ -1683,7 +1685,7 @@ static int remote_partition_enable(struct >> cpuset *cs, int new_prs, >>       if (cpumask_empty(tmp->new_cpus) || >>           cpumask_intersects(tmp->new_cpus, subpartitions_cpus) || >>           cpumask_subset(top_cpuset.effective_cpus, tmp->new_cpus)) >> -        return 0; >> +        return PERR_INVCPUS; >>         spin_lock_irq(&callback_lock); >>       isolcpus_updated = partition_xcpus_add(new_prs, NULL, >> tmp->new_cpus); >> @@ -1698,7 +1700,7 @@ static int remote_partition_enable(struct >> cpuset *cs, int new_prs, >>        */ >>       update_tasks_cpumask(&top_cpuset, tmp->new_cpus); >>       update_sibling_cpumasks(&top_cpuset, NULL, tmp); >> -    return 1; >> +    return 0; >>   } > > Since you are changing the meaning of the function returned value, you > should also update the return value comment as well. > >>     /* >> @@ -3151,24 +3153,26 @@ static int update_prstate(struct cpuset *cs, >> int new_prs) >>           goto out; >>         if (!old_prs) { >> -        enum partition_cmd cmd = (new_prs == PRS_ROOT) >> -                       ? partcmd_enable : partcmd_enablei; >> - >>           /* >> -         * cpus_allowed and exclusive_cpus cannot be both empty. >> -         */ >> -        if (xcpus_empty(cs)) { >> -            err = PERR_CPUSEMPTY; >> -            goto out; >> -        } >> +        * If parent is valid partition, enable local partiion. >> +        * Otherwise, enable a remote partition. >> +        */ >> +        if (is_partition_valid(parent)) { >> +            enum partition_cmd cmd = (new_prs == PRS_ROOT) >> +                           ? partcmd_enable : partcmd_enablei; >>   -        err = update_parent_effective_cpumask(cs, cmd, NULL, >> &tmpmask); >> -        /* >> -         * If an attempt to become local partition root fails, >> -         * try to become a remote partition root instead. >> -         */ >> -        if (err && remote_partition_enable(cs, new_prs, &tmpmask)) >> -            err = 0; >> +            /* >> +             * cpus_allowed and exclusive_cpus cannot be both empty. >> +             */ >> +            if (xcpus_empty(cs)) { >> +                err = PERR_CPUSEMPTY; >> +                goto out; >> +            } > > The xcpus_empty() check should be done for both local and remote > partition. > > Cheers, > Longman > >> + >> +            err = update_parent_effective_cpumask(cs, cmd, NULL, >> &tmpmask); >> +        } else { >> +            err = remote_partition_enable(cs, new_prs, &tmpmask); >> +        } >>       } else if (old_prs && new_prs) { >>           /* >>            * A change in load balance state only, no change in cpumasks.