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=-11.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 A9E56C433E5 for ; Tue, 21 Jul 2020 09:55:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 478F920684 for ; Tue, 21 Jul 2020 09:55:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JssAjKyY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 478F920684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 94E3B6B000E; Tue, 21 Jul 2020 05:55:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8FF556B0010; Tue, 21 Jul 2020 05:55:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 814DD6B0022; Tue, 21 Jul 2020 05:55:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 6BA446B000E for ; Tue, 21 Jul 2020 05:55:30 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id DEF1A82499B9 for ; Tue, 21 Jul 2020 09:55:29 +0000 (UTC) X-FDA: 77061625578.22.goat32_030875a26f2c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id 8F225180A0941 for ; Tue, 21 Jul 2020 09:55:29 +0000 (UTC) X-HE-Tag: goat32_030875a26f2c X-Filterd-Recvd-Size: 5933 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Tue, 21 Jul 2020 09:55:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595325328; 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=1XnvnThZnc7BMSa0y7ll+MrXkseUeXuMgZvuNS+LSeM=; b=JssAjKyYrUIHx+LsQscreSY36VDaLTXITInvkFnw7t7Ew/NwUCvQX5uXAgKyZQ17Jqy0Ec 0wwl5MGmkFs32mPg+x6IsR5hvZpEUaQr3Nd/AarVm6uGp6YnQJj9KLLPhD440Oo03U6SL2 uPsKX3GD9E81a39aydQVZ0XXXvai/EM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-475-AdemcYfsN6Wr2Mh9BhQkmQ-1; Tue, 21 Jul 2020 05:55:24 -0400 X-MC-Unique: AdemcYfsN6Wr2Mh9BhQkmQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5A1FE1B2C980; Tue, 21 Jul 2020 09:55:23 +0000 (UTC) Received: from localhost (ovpn-12-170.pek2.redhat.com [10.72.12.170]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AECD7C0060; Tue, 21 Jul 2020 09:55:22 +0000 (UTC) Date: Tue, 21 Jul 2020 17:55:20 +0800 From: Baoquan He To: Mike Kravetz Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org Subject: Re: [PATCH 5/5] mm/hugetl.c: warn out if expected count of huge pages adjustment is not achieved Message-ID: <20200721095520.GN32539@MiWiFi-R3L-srv> References: <20200720062623.13135-1-bhe@redhat.com> <20200720062623.13135-6-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Rspamd-Queue-Id: 8F225180A0941 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 07/20/20 at 05:38pm, Mike Kravetz wrote: > On 7/19/20 11:26 PM, Baoquan He wrote: > > A customer complained that no any message is printed out when failed to > > allocate explicitly specified number of persistent huge pages. That > > specifying can be done by writing into /proc/sys/vm/nr_hugepages to > > increase the persisten huge pages. > > > > In the current code, it takes the best effort way to allocate the expected > > number of huge pages. If only succeeding to get part of them, no any > > information is printed out. > > > > Here try to send out warning message if the expected number of huge pages > > adjustment is not achieved, including increasing and decreasing the count > > of persistent huge pages. > > Perhaps change the wording a bit, > > A customer complained that no message is logged when the number of > persistent huge pages is not changed to the exact value written to > the sysfs or proc nr_hugepages file. > > In the current code, a best effort is made to satisfy requests made > via the nr_hugepages file. However, requests may be only partially > satisfied. > > Log a message if the code was unsuccessful in fully satisfying a > request. This includes both increasing and decreasing the number > of persistent huge pages. Thanks, sounds much better, I will use these to replace the old log. > > > > > Signed-off-by: Baoquan He > > --- > > mm/hugetlb.c | 13 ++++++++++++- > > 1 file changed, 12 insertions(+), 1 deletion(-) > > I am not opposed to this patch. However, I believe the best way for a user > to determine if their request was successful is to compare the value of > nr_hugepages to the value which was written. Agree. While from our customer's request, they told the log can help 'Easily detect and analyse previous reservation failures'. > > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 467894d8332a..1dfb5d9e4e06 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -2661,7 +2661,7 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed, > > static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, > > nodemask_t *nodes_allowed) > > { > > - unsigned long min_count, ret; > > + unsigned long min_count, ret, old_max; > > NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL); > > > > /* > > @@ -2723,6 +2723,7 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, > > * pool might be one hugepage larger than it needs to be, but > > * within all the constraints specified by the sysctls. > > */ > > + old_max = persistent_huge_pages(h); > > while (h->surplus_huge_pages && count > persistent_huge_pages(h)) { > > if (!adjust_pool_surplus(h, nodes_allowed, -1)) > > break; > > @@ -2779,6 +2780,16 @@ static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid, > > } > > out: > > h->max_huge_pages = persistent_huge_pages(h); > > + if (count != h->max_huge_pages) { > > + char buf[32]; > > + > > + string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32); > > + pr_warn("HugeTLB: %s %lu of page size %s failed. Only %s %lu hugepages.\n", > > + count > old_max ? "increasing" : "decreasing", > > + abs(count - old_max), buf, > > + count > old_max ? "increased" : "decreased", > > + abs(old_max - h->max_huge_pages)); > > + } > > spin_unlock(&hugetlb_lock); > > I would prefer if we drop the lock before logging the message. That would > involve grabbing the value of h->max_huge_pages before dropping the lock. Sure, will change. We should try to release the lock's burden. Thanks.