From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 9E76D6B0038 for ; Tue, 14 Mar 2017 21:19:31 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id b2so6736468pgc.6 for ; Tue, 14 Mar 2017 18:19:31 -0700 (PDT) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id w127si253463pfw.347.2017.03.14.18.19.30 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Mar 2017 18:19:30 -0700 (PDT) From: "Huang\, Ying" Subject: Re: [PATCH -mm -v6 3/9] mm, THP, swap: Add swap cluster allocate/free functions References: <20170308072613.17634-1-ying.huang@intel.com> <20170308072613.17634-4-ying.huang@intel.com> <1489533213.2733.33.camel@linux.intel.com> Date: Wed, 15 Mar 2017 09:19:27 +0800 In-Reply-To: <1489533213.2733.33.camel@linux.intel.com> (Tim Chen's message of "Tue, 14 Mar 2017 16:13:33 -0700") Message-ID: <87wpbrcp5s.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Tim Chen Cc: "Huang, Ying" , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrea Arcangeli , "Kirill A . Shutemov" , Hugh Dickins , Shaohua Li , Minchan Kim , Rik van Riel Tim Chen writes: > On Wed, 2017-03-08 at 15:26 +0800, Huang, Ying wrote: >> From: Huang Ying >> >> The swap cluster allocation/free functions are added based on the >> existing swap cluster management mechanism for SSD.A A These functions >> don't work for the rotating hard disks because the existing swap cluster >> management mechanism doesn't work for them.A A The hard disks support may >> be added if someone really need it.A A But that needn't be included in >> this patchset. >> >> This will be used for the THP (Transparent Huge Page) swap support. >> Where one swap cluster will hold the contents of each THP swapped out. >> >> Cc: Andrea Arcangeli >> Cc: Kirill A. Shutemov >> Cc: Hugh Dickins >> Cc: Shaohua Li >> Cc: Minchan Kim >> Cc: Rik van Riel >> Signed-off-by: "Huang, Ying" >> --- >> A mm/swapfile.c | 217 +++++++++++++++++++++++++++++++++++++++++----------------- >> A 1 file changed, 156 insertions(+), 61 deletions(-) >> >> diff --git a/mm/swapfile.c b/mm/swapfile.c >> index a744604384ff..91876c33114b 100644 >> --- a/mm/swapfile.c >> +++ b/mm/swapfile.c >> @@ -378,6 +378,14 @@ static void swap_cluster_schedule_discard(struct swap_info_struct *si, >> A schedule_work(&si->discard_work); >> A } >> A >> +static void __free_cluster(struct swap_info_struct *si, unsigned long idx) >> +{ >> + struct swap_cluster_info *ci = si->cluster_info; >> + >> + cluster_set_flag(ci + idx, CLUSTER_FLAG_FREE); >> + cluster_list_add_tail(&si->free_clusters, ci, idx); >> +} >> + >> A /* >> A * Doing discard actually. After a cluster discard is finished, the cluster >> A * will be added to free cluster list. caller should hold si->lock. >> @@ -398,10 +406,7 @@ static void swap_do_scheduled_discard(struct swap_info_struct *si) >> A >> A spin_lock(&si->lock); >> A ci = lock_cluster(si, idx * SWAPFILE_CLUSTER); >> - cluster_set_flag(ci, CLUSTER_FLAG_FREE); >> - unlock_cluster(ci); >> - cluster_list_add_tail(&si->free_clusters, info, idx); >> - ci = lock_cluster(si, idx * SWAPFILE_CLUSTER); >> + __free_cluster(si, idx); >> A memset(si->swap_map + idx * SWAPFILE_CLUSTER, >> A 0, SWAPFILE_CLUSTER); >> A unlock_cluster(ci); > > The __free_cluster definition and the above change to eliminate > the extra unlock_cluster and lock_cluster can perhaps be broken up > as a separate patch. A It can be independent of THP changes. I think the change may have no value by itself without THP changes. There will be only 1 user of __free_cluster() and the lock change is trivial too. So I think it may be better just to keep it as that? Best Regards, Huang, Ying -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org