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 007716B0388 for ; Tue, 14 Mar 2017 19:13:35 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id q126so2331604pga.0 for ; Tue, 14 Mar 2017 16:13:34 -0700 (PDT) Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id w70si80107pgw.402.2017.03.14.16.13.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 14 Mar 2017 16:13:34 -0700 (PDT) Message-ID: <1489533213.2733.33.camel@linux.intel.com> Subject: Re: [PATCH -mm -v6 3/9] mm, THP, swap: Add swap cluster allocate/free functions From: Tim Chen Date: Tue, 14 Mar 2017 16:13:33 -0700 In-Reply-To: <20170308072613.17634-4-ying.huang@intel.com> References: <20170308072613.17634-1-ying.huang@intel.com> <20170308072613.17634-4-ying.huang@intel.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: "Huang, Ying" , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrea Arcangeli , "Kirill A . Shutemov" , Hugh Dickins , Shaohua Li , Minchan Kim , Rik van Riel 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. Tim -- 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