From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <45DB51E3.8090909@redhat.com> Date: Tue, 20 Feb 2007 14:54:11 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] free swap space when (re)activating page References: <45D63445.5070005@redhat.com> <45DAF794.2000209@redhat.com> <45DB25E1.7030504@redhat.com> <45DB4C87.6050809@redhat.com> In-Reply-To: <45DB4C87.6050809@redhat.com> Content-Type: multipart/mixed; boundary="------------040204040601060701030304" Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Christoph Lameter , linux-kernel , linux-mm , Andrew Morton List-ID: This is a multi-part message in MIME format. --------------040204040601060701030304 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Rik van Riel wrote: > ... because I think this is what my patch does :) Never mind, I see it now. The attached patch should be correct. Btw, why do we not call pagevec_strip on the pages on l_active? I assume we want to reclaim their buffer heads, too... -- All Rights Reversed --------------040204040601060701030304 Content-Type: text/x-patch; name="linux-2.6-swapfree.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="linux-2.6-swapfree.patch" --- linux-2.6.20.noarch/mm/vmscan.c.swapfree 2007-02-20 06:44:13.000000000 -0500 +++ linux-2.6.20.noarch/mm/vmscan.c 2007-02-20 06:54:10.000000000 -0500 @@ -587,6 +587,9 @@ free_it: continue; activate_locked: + /* Not a candidate for swapping, so reclaim swap space. */ + if (PageSwapCache(page) && vm_swap_full()) + remove_exclusive_swap_page(page); SetPageActive(page); pgactivate++; keep_locked: @@ -889,6 +892,8 @@ force_reclaim_mapped: __mod_zone_page_state(zone, NR_ACTIVE, pgmoved); pgmoved = 0; spin_unlock_irq(&zone->lru_lock); + if (vm_swap_full()) + pagevec_swap_free(&pvec); __pagevec_release(&pvec); spin_lock_irq(&zone->lru_lock); } @@ -899,6 +904,8 @@ force_reclaim_mapped: __count_vm_events(PGDEACTIVATE, pgdeactivate); spin_unlock_irq(&zone->lru_lock); + if (vm_swap_full()) + pagevec_swap_free(&pvec); pagevec_release(&pvec); } --- linux-2.6.20.noarch/mm/swap.c.swapfree 2007-02-04 13:44:54.000000000 -0500 +++ linux-2.6.20.noarch/mm/swap.c 2007-02-20 06:44:17.000000000 -0500 @@ -420,6 +420,26 @@ void pagevec_strip(struct pagevec *pvec) } } +/* + * Try to free swap space from the pages in a pagevec + */ +void pagevec_swap_free(struct pagevec *pvec) +{ + int i; + + for (i = 0; i < pagevec_count(pvec); i++) { + struct page *page = pvec->pages[i]; + + if (PageSwapCache(page) && !TestSetPageLocked(page)) { + if (PageSwapCache(page)) + remove_exclusive_swap_page(page); + unlock_page(page); + if (printk_ratelimit()) + printk("kswapd freed a swap space\n"); + } + } +} + /** * pagevec_lookup - gang pagecache lookup * @pvec: Where the resulting pages are placed --- linux-2.6.20.noarch/include/linux/pagevec.h.swapfree 2007-02-04 13:44:54.000000000 -0500 +++ linux-2.6.20.noarch/include/linux/pagevec.h 2007-02-20 06:44:17.000000000 -0500 @@ -26,6 +26,7 @@ void __pagevec_free(struct pagevec *pvec void __pagevec_lru_add(struct pagevec *pvec); void __pagevec_lru_add_active(struct pagevec *pvec); void pagevec_strip(struct pagevec *pvec); +void pagevec_swap_free(struct pagevec *pvec); unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, pgoff_t start, unsigned nr_pages); unsigned pagevec_lookup_tag(struct pagevec *pvec, --------------040204040601060701030304-- -- 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