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=-9.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 05202C4338F for ; Mon, 16 Aug 2021 23:27:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A3F26606A5 for ; Mon, 16 Aug 2021 23:27:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A3F26606A5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 3F9076B0072; Mon, 16 Aug 2021 19:27:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3AA416B0073; Mon, 16 Aug 2021 19:27:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2BEF08D0001; Mon, 16 Aug 2021 19:27:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0217.hostedemail.com [216.40.44.217]) by kanga.kvack.org (Postfix) with ESMTP id 0FE896B0072 for ; Mon, 16 Aug 2021 19:27:52 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id BA4EC1815522D for ; Mon, 16 Aug 2021 23:27:51 +0000 (UTC) X-FDA: 78482533542.21.D0315BB Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf03.hostedemail.com (Postfix) with ESMTP id 67A2A3004A65 for ; Mon, 16 Aug 2021 23:27:51 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 5874B60F35; Mon, 16 Aug 2021 23:27:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1629156470; bh=OdMJAwPOuwuJZ7/QF/0/fC6Kak6vxLEJ4D/q/1SGn98=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=WCOKRmXg1hB/Q8MAwBJc2nIRAyNLQ+hdHoANuA5v1B7YXHUyI3e7TDOJ6RcKbjwTb C4UhqWI0koQskgJ8yY8iaHLJc+3nqaHQ7+iMQcq1IHUqxiP+hqbyH6Dc2LxlLG4pYG alNTlBWeB/LC2YLkSfra2NwA7maGCxptzupMPuyw= Date: Mon, 16 Aug 2021 16:27:49 -0700 From: Andrew Morton To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, David Hildenbrand , Michal Hocko , Oscar Salvador , Zi Yan , Muchun Song , Naoya Horiguchi , David Rientjes Subject: Re: [PATCH RESEND 0/8] hugetlb: add demote/split page functionality Message-Id: <20210816162749.22b921a61156a091f3e1d14d@linux-foundation.org> In-Reply-To: <20210816224953.157796-1-mike.kravetz@oracle.com> References: <20210816224953.157796-1-mike.kravetz@oracle.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf03.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=WCOKRmXg; spf=pass (imf03.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 67A2A3004A65 X-Stat-Signature: w7bikwbp8fni818mt9pqwowr3majkipm X-HE-Tag: 1629156471-527633 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: Also, pushback... On Mon, 16 Aug 2021 15:49:45 -0700 Mike Kravetz wrote: > > Real world use cases > -------------------- > There are groups today using hugetlb pages to back VMs on x86. Their > use case is as described above. They have experienced the issues with > performance and not necessarily getting the excepted number smaller huge ("number of") > pages after free/allocate cycle. > It really is a ton of new code. I think we're owed much more detail about the problem than the above. To be confident that all this material is truly justified? Also, some selftests and benchmarking code in tools/testing/selftests would be helpful?