From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933288AbdBVSvo (ORCPT ); Wed, 22 Feb 2017 13:51:44 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:54804 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754855AbdBVSvX (ORCPT ); Wed, 22 Feb 2017 13:51:23 -0500 Smtp-Origin-Hostprefix: devbig From: Shaohua Li Smtp-Origin-Hostname: devbig638.prn2.facebook.com To: , CC: , , , , , , , Smtp-Origin-Cluster: prn2c22 Subject: [PATCH V4 1/6] mm: delete unnecessary TTU_* flags Date: Wed, 22 Feb 2017 10:50:39 -0800 Message-ID: <6e99fbb58c019dac280dde73a96586c0eba880d0.1487788131.git.shli@fb.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: References: X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-02-22_12:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Johannes pointed out TTU_LZFREE is unnecessary. It's true because we always have the flag set if we want to do an unmap. For cases we don't do an unmap, the TTU_LZFREE part of code should never run. Also the TTU_UNMAP is unnecessary. If no other flags set (for example, TTU_MIGRATION), an unmap is implied. Cc: Michal Hocko Cc: Minchan Kim Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Andrew Morton Suggested-by: Johannes Weiner Signed-off-by: Shaohua Li --- include/linux/rmap.h | 2 -- mm/memory-failure.c | 2 +- mm/rmap.c | 2 +- mm/vmscan.c | 11 ++++------- 4 files changed, 6 insertions(+), 11 deletions(-) diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 8c89e90..e2cd8f9 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -83,10 +83,8 @@ struct anon_vma_chain { }; enum ttu_flags { - TTU_UNMAP = 1, /* unmap mode */ TTU_MIGRATION = 2, /* migration mode */ TTU_MUNLOCK = 4, /* munlock mode */ - TTU_LZFREE = 8, /* lazy free mode */ TTU_SPLIT_HUGE_PMD = 16, /* split huge PMD if any */ TTU_IGNORE_MLOCK = (1 << 8), /* ignore mlock */ diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 3d0f2fd..b78d080 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -906,7 +906,7 @@ EXPORT_SYMBOL_GPL(get_hwpoison_page); static int hwpoison_user_mappings(struct page *p, unsigned long pfn, int trapno, int flags, struct page **hpagep) { - enum ttu_flags ttu = TTU_UNMAP | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; + enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS; struct address_space *mapping; LIST_HEAD(tokill); int ret; diff --git a/mm/rmap.c b/mm/rmap.c index 8774791..96eb85c 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1418,7 +1418,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, */ VM_BUG_ON_PAGE(!PageSwapCache(page), page); - if (!PageDirty(page) && (flags & TTU_LZFREE)) { + if (!PageDirty(page)) { /* It's a freeable page by MADV_FREE */ dec_mm_counter(mm, MM_ANONPAGES); rp->lazyfreed++; diff --git a/mm/vmscan.c b/mm/vmscan.c index 26c3b40..68ea50d 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -971,7 +971,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, int may_enter_fs; enum page_references references = PAGEREF_RECLAIM_CLEAN; bool dirty, writeback; - bool lazyfree = false; int ret = SWAP_SUCCESS; cond_resched(); @@ -1125,7 +1124,6 @@ static unsigned long shrink_page_list(struct list_head *page_list, goto keep_locked; if (!add_to_swap(page, page_list)) goto activate_locked; - lazyfree = true; may_enter_fs = 1; /* Adding to swap updated mapping */ @@ -1143,9 +1141,8 @@ static unsigned long shrink_page_list(struct list_head *page_list, * processes. Try to unmap it here. */ if (page_mapped(page) && mapping) { - switch (ret = try_to_unmap(page, lazyfree ? - (ttu_flags | TTU_BATCH_FLUSH | TTU_LZFREE) : - (ttu_flags | TTU_BATCH_FLUSH))) { + switch (ret = try_to_unmap(page, + ttu_flags | TTU_BATCH_FLUSH)) { case SWAP_FAIL: nr_unmap_fail++; goto activate_locked; @@ -1353,7 +1350,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, } ret = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc, - TTU_UNMAP|TTU_IGNORE_ACCESS, NULL, true); + TTU_IGNORE_ACCESS, NULL, true); list_splice(&clean_pages, page_list); mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, -ret); return ret; @@ -1760,7 +1757,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, if (nr_taken == 0) return 0; - nr_reclaimed = shrink_page_list(&page_list, pgdat, sc, TTU_UNMAP, + nr_reclaimed = shrink_page_list(&page_list, pgdat, sc, 0, &stat, false); spin_lock_irq(&pgdat->lru_lock); -- 2.9.3