Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932970AbaFLJix (ORCPT ); Thu, 12 Jun 2014 05:38:53 -0400 Received: from mail-pd0-f175.google.com ([209.85.192.175]:35364 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932740AbaFLJiv (ORCPT ); Thu, 12 Jun 2014 05:38:51 -0400 From: Chen Yucong To: akpm@linux-foundation.org Cc: mgorman@suse.de, hannes@cmpxchg.org, mhocko@suse.cz, riel@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chen Yucong Subject: [PATCH] mm/vmscan.c: wrap five parameters into arg_container in shrink_page_list() Date: Thu, 12 Jun 2014 17:36:35 +0800 Message-Id: <1402565795-706-1-git-send-email-slaoub@gmail.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org shrink_page_list() has too many arguments that have already reached ten. Some of those arguments and temporary variables introduces extra 80 bytes on the stack. This patch wraps five parameters into arg_container and removes some temporary variables, thus making shrink_page_list() to consume fewer stack space. Before mm/vmscan.c is modified: text data bss dec hex filename 6876698 957224 966656 8800578 864942 vmlinux-3.15 After mm/vmscan.c is changed: text data bss dec hex filename 6876506 957224 966656 8800386 864882 vmlinux-3.15 Signed-off-by: Chen Yucong --- mm/vmscan.c | 64 +++++++++++++++++++++++++++-------------------------------- 1 file changed, 29 insertions(+), 35 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index a8ffe4e..538cdcf 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -790,6 +790,14 @@ static void page_check_dirty_writeback(struct page *page, mapping->a_ops->is_dirty_writeback(page, dirty, writeback); } +struct arg_container { + unsigned long nr_dirty; + unsigned long nr_unqueued_dirty; + unsigned long nr_congested; + unsigned long nr_writeback; + unsigned long nr_immediate; +}; + /* * shrink_page_list() returns the number of reclaimed pages */ @@ -797,22 +805,13 @@ static unsigned long shrink_page_list(struct list_head *page_list, struct zone *zone, struct scan_control *sc, enum ttu_flags ttu_flags, - unsigned long *ret_nr_dirty, - unsigned long *ret_nr_unqueued_dirty, - unsigned long *ret_nr_congested, - unsigned long *ret_nr_writeback, - unsigned long *ret_nr_immediate, + struct arg_container *ac, bool force_reclaim) { LIST_HEAD(ret_pages); LIST_HEAD(free_pages); int pgactivate = 0; - unsigned long nr_unqueued_dirty = 0; - unsigned long nr_dirty = 0; - unsigned long nr_congested = 0; unsigned long nr_reclaimed = 0; - unsigned long nr_writeback = 0; - unsigned long nr_immediate = 0; cond_resched(); @@ -858,10 +857,10 @@ static unsigned long shrink_page_list(struct list_head *page_list, */ page_check_dirty_writeback(page, &dirty, &writeback); if (dirty || writeback) - nr_dirty++; + ac->nr_dirty++; if (dirty && !writeback) - nr_unqueued_dirty++; + ac->nr_unqueued_dirty++; /* * Treat this page as congested if the underlying BDI is or if @@ -872,7 +871,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, mapping = page_mapping(page); if ((mapping && bdi_write_congested(mapping->backing_dev_info)) || (writeback && PageReclaim(page))) - nr_congested++; + ac->nr_congested++; /* * If a page at the tail of the LRU is under writeback, there @@ -916,7 +915,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, if (current_is_kswapd() && PageReclaim(page) && zone_is_reclaim_writeback(zone)) { - nr_immediate++; + ac->nr_immediate++; goto keep_locked; /* Case 2 above */ @@ -934,7 +933,7 @@ static unsigned long shrink_page_list(struct list_head *page_list, * and it's also appropriate in global reclaim. */ SetPageReclaim(page); - nr_writeback++; + ac->nr_writeback++; goto keep_locked; @@ -1132,11 +1131,6 @@ keep: list_splice(&ret_pages, page_list); count_vm_events(PGACTIVATE, pgactivate); mem_cgroup_uncharge_end(); - *ret_nr_dirty += nr_dirty; - *ret_nr_congested += nr_congested; - *ret_nr_unqueued_dirty += nr_unqueued_dirty; - *ret_nr_writeback += nr_writeback; - *ret_nr_immediate += nr_immediate; return nr_reclaimed; } @@ -1148,7 +1142,8 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, .priority = DEF_PRIORITY, .may_unmap = 1, }; - unsigned long ret, dummy1, dummy2, dummy3, dummy4, dummy5; + unsigned long ret; + struct arg_container dummy; struct page *page, *next; LIST_HEAD(clean_pages); @@ -1161,8 +1156,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, } ret = shrink_page_list(&clean_pages, zone, &sc, - TTU_UNMAP|TTU_IGNORE_ACCESS, - &dummy1, &dummy2, &dummy3, &dummy4, &dummy5, true); + TTU_UNMAP|TTU_IGNORE_ACCESS, &dummy, true); list_splice(&clean_pages, page_list); mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret); return ret; @@ -1469,11 +1463,13 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, unsigned long nr_scanned; unsigned long nr_reclaimed = 0; unsigned long nr_taken; - unsigned long nr_dirty = 0; - unsigned long nr_congested = 0; - unsigned long nr_unqueued_dirty = 0; - unsigned long nr_writeback = 0; - unsigned long nr_immediate = 0; + struct arg_container ac = { + .nr_dirty = 0, + .nr_congested = 0, + .nr_unqueued_dirty = 0, + .nr_writeback = 0, + .nr_immediate = 0, + }; isolate_mode_t isolate_mode = 0; int file = is_file_lru(lru); struct zone *zone = lruvec_zone(lruvec); @@ -1515,9 +1511,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, return 0; nr_reclaimed = shrink_page_list(&page_list, zone, sc, TTU_UNMAP, - &nr_dirty, &nr_unqueued_dirty, &nr_congested, - &nr_writeback, &nr_immediate, - false); + &ac, false); spin_lock_irq(&zone->lru_lock); @@ -1554,7 +1548,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, * of pages under pages flagged for immediate reclaim and stall if any * are encountered in the nr_immediate check below. */ - if (nr_writeback && nr_writeback == nr_taken) + if (ac.nr_writeback && ac.nr_writeback == nr_taken) zone_set_flag(zone, ZONE_WRITEBACK); /* @@ -1566,7 +1560,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, * Tag a zone as congested if all the dirty pages scanned were * backed by a congested BDI and wait_iff_congested will stall. */ - if (nr_dirty && nr_dirty == nr_congested) + if (ac.nr_dirty && ac.nr_dirty == ac.nr_congested) zone_set_flag(zone, ZONE_CONGESTED); /* @@ -1576,7 +1570,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, * pages from reclaim context. It will forcibly stall in the * next check. */ - if (nr_unqueued_dirty == nr_taken) + if (ac.nr_unqueued_dirty == nr_taken) zone_set_flag(zone, ZONE_TAIL_LRU_DIRTY); /* @@ -1585,7 +1579,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, * implies that pages are cycling through the LRU faster than * they are written so also forcibly stall. */ - if ((nr_unqueued_dirty == nr_taken || nr_immediate) && + if ((ac.nr_unqueued_dirty == nr_taken || ac.nr_immediate) && current_may_throttle()) congestion_wait(BLK_RW_ASYNC, HZ/10); } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/