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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 AF681C49ED6 for ; Wed, 11 Sep 2019 15:15:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6C2D6206A5 for ; Wed, 11 Sep 2019 15:15:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="eqkcSKVD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6C2D6206A5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 02F816B0277; Wed, 11 Sep 2019 11:15:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F22096B0278; Wed, 11 Sep 2019 11:15:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E5FA46B0279; Wed, 11 Sep 2019 11:15:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0223.hostedemail.com [216.40.44.223]) by kanga.kvack.org (Postfix) with ESMTP id C68C96B0277 for ; Wed, 11 Sep 2019 11:15:05 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 26C441F238 for ; Wed, 11 Sep 2019 15:15:05 +0000 (UTC) X-FDA: 75922987770.12.mass54_839a9dc889060 X-HE-Tag: mass54_839a9dc889060 X-Filterd-Recvd-Size: 2694 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Sep 2019 15:15:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=9Ts7UUugH0BhHT6ILLki/cYvYfh0gbGfHUwu1u4OVw8=; b=eqkcSKVD5dOJFE9++guNrEOku ugiFibAd7qPBNs79ndiqk4OEMfpM6jqG9pkL4/PgcpCNl1VtuKFn9391adW0g8KjDRn/2DrF+1J6U Gr9Qok/kye4rT8b59JEpXjUD5TFaVMr1dMKnWFC1eFVqzm5ygXtuFoyp951ixiriwwS5gwhbBLUJi U94832VbTPNeOBMMpu72U5QpaeSWUmS1XVcFXhor3uG9GgdzzMslZ209al1WCJl3Y5KcH8iybTCOv TzToz2C27tIJC0cWry7yAwavYapdb8V1G9AK2EhVnWeXkTXCF7FjLQo30x4oe8pVDHIWBOhdbjt8s XWUFtI3tQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.2 #3 (Red Hat Linux)) id 1i84KZ-0008Ht-S4; Wed, 11 Sep 2019 15:14:51 +0000 Date: Wed, 11 Sep 2019 08:14:51 -0700 From: Matthew Wilcox To: Waiman Long Cc: Peter Zijlstra , Ingo Molnar , Will Deacon , Alexander Viro , Mike Kravetz , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Davidlohr Bueso Subject: Re: [PATCH 5/5] hugetlbfs: Limit wait time when trying to share huge PMD Message-ID: <20190911151451.GH29434@bombadil.infradead.org> References: <20190911150537.19527-1-longman@redhat.com> <20190911150537.19527-6-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190911150537.19527-6-longman@redhat.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000006, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Sep 11, 2019 at 04:05:37PM +0100, Waiman Long wrote: > When allocating a large amount of static hugepages (~500-1500GB) on a > system with large number of CPUs (4, 8 or even 16 sockets), performance > degradation (random multi-second delays) was observed when thousands > of processes are trying to fault in the data into the huge pages. The > likelihood of the delay increases with the number of sockets and hence > the CPUs a system has. This only happens in the initial setup phase > and will be gone after all the necessary data are faulted in. Can;t the application just specify MAP_POPULATE?