From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 14 Aug 2001 03:41:41 -0300 (BRST) From: Rik van Riel Subject: [PATCH] "drop behind" for buffers Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Alan Cox Cc: linux-mm@kvack.org List-ID: Hi Alan, the patch below bypasses page aging and drops buffers directly onto the inactive_dirty list when we have an excessive amount of buffercache pages. This should provide some of the benefits of drop behind for buffercache pages, while still giving the buffercache pages a good chance to stay resident in memory by being referenced while on the inactive_dirty list (and moved back onto the active list). regards, Rik -- IA64: a worthy successor to i860. --- linux/mm/vmscan.c.buffer Thu Aug 9 17:54:24 2001 +++ linux/mm/vmscan.c Thu Aug 9 17:55:09 2001 @@ -708,6 +708,8 @@ * This function will scan a portion of the active list to find * unused pages, those pages will then be moved to the inactive list. */ +#define too_many_buffers (atomic_read(&buffermem_pages) > \ + (num_physpages * buffer_mem.borrow_percent / 100)) int refill_inactive_scan(zone_t *zone, unsigned int priority, int target) { struct list_head * page_lru; @@ -770,6 +772,18 @@ page_active = 1; } } + + /* + * If the amount of buffer cache pages is too + * high we just move every buffer cache page we + * find to the inactive list. Eventually they'll + * be reclaimed there... + */ + if (page->buffers && !page->mapping && too_many_buffers) { + deactivate_page_nolock(page); + page_active = 0; + } + /* * If the page is still on the active list, move it * to the other end of the list. Otherwise we exit if -- 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/