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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B476BC4332F for ; Wed, 2 Nov 2022 02:11:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229695AbiKBCLZ (ORCPT ); Tue, 1 Nov 2022 22:11:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230133AbiKBCLT (ORCPT ); Tue, 1 Nov 2022 22:11:19 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC1021F2C0 for ; Tue, 1 Nov 2022 19:11:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667355078; x=1698891078; h=from:to:cc:subject:references:date:in-reply-to: message-id:mime-version; bh=O6XTGElfGoUAX2ClG0cppHS3e2wQBWvL3CUDavNdeKk=; b=JIhHNitfqjqG8JTwkYg5PUbi20LuErEfdb56vXyZE6DPgmXDnLec/rI1 KSQs709gQNXJ3+P993GdIcJZdY7S6dkFztazbPnw9zsgKKypmfXCxnWXf Q28U6NfK2Z+6TpMtJs7rsCOPY56UIfuFl2AYzV/+JkQbd5tigWueS5zl0 Hx3KvGvlvVqiHLmbgnz1EOo0EuVBV3awmv/uOnMzVMsSGHqElOkZAFXX3 rnCABbis5HwxNIdwRJT0C5pnCUA/R/dVCD2Ucvknf61zYd6+U1V3RpZsf l66C1vouzi/axjqckKJ1w+dMZZLEQ+dn5kBRqljsHzreKt2yDzPyLLgTN Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10518"; a="289679550" X-IronPort-AV: E=Sophos;i="5.95,232,1661842800"; d="scan'208";a="289679550" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2022 19:11:18 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10518"; a="776716072" X-IronPort-AV: E=Sophos;i="5.95,232,1661842800"; d="scan'208";a="776716072" Received: from yhuang6-desk2.sh.intel.com (HELO yhuang6-desk2.ccr.corp.intel.com) ([10.238.208.55]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Nov 2022 19:11:16 -0700 From: "Huang, Ying" To: Matthew Wilcox Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Zi Yan , Yang Shi , Baolin Wang , Oscar Salvador Subject: Re: [RFC 2/2] migrate: convert migrate_pages() to use folios References: <20221101062137.83649-1-ying.huang@intel.com> <20221101062137.83649-3-ying.huang@intel.com> Date: Wed, 02 Nov 2022 10:10:37 +0800 In-Reply-To: (Matthew Wilcox's message of "Tue, 1 Nov 2022 13:02:47 +0000") Message-ID: <8735b2cdia.fsf@yhuang6-desk2.ccr.corp.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Matthew Wilcox writes: > On Tue, Nov 01, 2022 at 02:21:37PM +0800, Huang Ying wrote: >> - is_thp = PageTransHuge(page) && !PageHuge(page); >> - nr_subpages = compound_nr(page); >> + is_large = folio_test_large(folio) && !PageHuge(&folio->page); > > We have folio_test_hugetlb() to replace PageHuge(). Thanks! Will change this in the next version. >> count_vm_events(PGMIGRATE_SUCCESS, nr_succeeded); >> count_vm_events(PGMIGRATE_FAIL, nr_failed_pages); >> - count_vm_events(THP_MIGRATION_SUCCESS, nr_thp_succeeded); >> - count_vm_events(THP_MIGRATION_FAIL, nr_thp_failed); >> - count_vm_events(THP_MIGRATION_SPLIT, nr_thp_split); >> - trace_mm_migrate_pages(nr_succeeded, nr_failed_pages, nr_thp_succeeded, >> - nr_thp_failed, nr_thp_split, mode, reason); >> + count_vm_events(THP_MIGRATION_SUCCESS, nr_large_succeeded); >> + count_vm_events(THP_MIGRATION_FAIL, nr_large_failed); >> + count_vm_events(THP_MIGRATION_SPLIT, nr_split); >> + trace_mm_migrate_pages(nr_succeeded, nr_failed_pages, nr_large_succeeded, >> + nr_large_failed, nr_split, mode, reason); > > I think this is the biggest question with this patch -- how (or whether) > to account folios in size between PMD and PTE size. Since it's > _called_ THP, I've tended to make the statistics conditional on > folio_test_pmd_mappable() rather than simply being folio_test_large(). Yes. This is my biggest concern during development too. In the next version, I will distinguish THP and other large folios (between PMD and PTE size) and do statistics accordingly. Best Regards, Huang, Ying