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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 166BAC433DF for ; Wed, 3 Jun 2020 02:57:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E54622072F for ; Wed, 3 Jun 2020 02:57:45 +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="lhrscTOz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725905AbgFCC5p (ORCPT ); Tue, 2 Jun 2020 22:57:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725780AbgFCC5o (ORCPT ); Tue, 2 Jun 2020 22:57:44 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7F5F8C08C5C0 for ; Tue, 2 Jun 2020 19:57:44 -0700 (PDT) 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; bh=PWX9BV+vrW0IrePlfAaDQhinjrn9zTJLBodSCt06FbY=; b=lhrscTOzVwIDVU9rOr3VjPrNLb DAFba5itcmMxU17lBm+QnpqXLrSY/e+XOeRTPlThZcYZx1ppCr2W8JTn2Jnne0JYqzwraWqrLdiAr JfQastEPDHKi2lzpo2eTzKD+R//w++FiRBv5/r5eivu0dXnPnQFIOO7MjbCpqP+4CM8MhWK3Ei0yW 9j6bDFdY2T8lVvdPx8vgdFcAWruRfm8HEKh0LMQMXa2yI3Q1Zs2rMEaaPo2OLoujHZEnmU04ucHAg m2vnQyXlyfCaer20yXFYn7wI14cAUNFWHKwtL/XhcC6ufHPCCN0iD3ljoxi5Yjskbf7njojeHQOT9 dbZYjmUA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jgJar-0001dn-SF; Wed, 03 Jun 2020 02:57:29 +0000 Date: Tue, 2 Jun 2020 19:57:29 -0700 From: Matthew Wilcox To: Anshuman Khandual Cc: linux-mm@kvack.org, hughd@google.com, Naoya Horiguchi , Zi Yan , John Hubbard , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmstat: Add events for PMD based THP migration without split Message-ID: <20200603025729.GO19604@bombadil.infradead.org> References: <1590118444-21601-1-git-send-email-anshuman.khandual@arm.com> <20200602150141.GN19604@bombadil.infradead.org> <2d4634ce-9167-6ca6-fb91-f3c671fff672@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2d4634ce-9167-6ca6-fb91-f3c671fff672@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 03, 2020 at 06:56:57AM +0530, Anshuman Khandual wrote: > On 06/02/2020 08:31 PM, Matthew Wilcox wrote: > > On Fri, May 22, 2020 at 09:04:04AM +0530, Anshuman Khandual wrote: > >> This adds the following two new VM events which will help in validating PMD > >> based THP migration without split. Statistics reported through these events > >> will help in performance debugging. > >> > >> 1. THP_PMD_MIGRATION_SUCCESS > >> 2. THP_PMD_MIGRATION_FAILURE > > > > There's nothing actually PMD specific about these events, is there? > > If we have a THP of a non-PMD size, you'd want that reported through the > > same statistic, wouldn't you? > > Yes, there is nothing PMD specific here and we would use the same statistics > for non-PMD size THP migration (if any) as well. But is THP migration really > supported for non-PMD sizes ? CONFIG_ARCH_ENABLE_THP_MIGRATION depends upon > CONFIG_TRANSPARENT_HUGEPAGE without being specific or denying about possible > PUD level support. Fair enough, will drop the PMD from the events and their > functions. I guess you haven't read my large pages patchset?