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Date: Mon, 27 Aug 2018 15:55:35 +0800 From: Huang Ying <ying.huang@...el.com> To: Andrew Morton <akpm@...ux-foundation.org> Cc: linux-mm@...ck.org, linux-kernel@...r.kernel.org, Huang Ying <ying.huang@...el.com>, Dave Hansen <dave.hansen@...ux.intel.com>, Michal Hocko <mhocko@...e.com>, Johannes Weiner <hannes@...xchg.org>, Shaohua Li <shli@...nel.org>, Hugh Dickins <hughd@...gle.com>, Minchan Kim <minchan@...nel.org> Subject: [PATCH 3/3] swap: Clear si->swap_map[] in swap_free_cluster() si->swap_map[] of the swap entries in cluster needs to be cleared during freeing. Previously, this is done in the caller of swap_free_cluster(). This may cause code duplication (one user now, will add more users later) and lock/unlock cluster unnecessarily. In this patch, the clearing code is moved to swap_free_cluster() to avoid the downside. Signed-off-by: "Huang, Ying" <ying.huang@...el.com> Cc: Dave Hansen <dave.hansen@...ux.intel.com> Cc: Michal Hocko <mhocko@...e.com> Cc: Johannes Weiner <hannes@...xchg.org> Cc: Shaohua Li <shli@...nel.org> Cc: Hugh Dickins <hughd@...gle.com> Cc: Minchan Kim <minchan@...nel.org> --- mm/swapfile.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index ef974bbd7715..97a1bd1a7c9a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -933,6 +933,7 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx) struct swap_cluster_info *ci; ci = lock_cluster(si, offset); + memset(si->swap_map + offset, 0, SWAPFILE_CLUSTER); cluster_set_count_flag(ci, 0, 0); free_cluster(si, idx); unlock_cluster(ci); @@ -1309,9 +1310,6 @@ void put_swap_page(struct page *page, swp_entry_t entry) if (free_entries == SWAPFILE_CLUSTER) { unlock_cluster_or_swap_info(si, ci); spin_lock(&si->lock); - ci = lock_cluster(si, offset); - memset(map, 0, SWAPFILE_CLUSTER); - unlock_cluster(ci); mem_cgroup_uncharge_swap(entry, SWAPFILE_CLUSTER); swap_free_cluster(si, idx); spin_unlock(&si->lock); -- 2.16.4
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