Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754704Ab1BSXlc (ORCPT ); Sat, 19 Feb 2011 18:41:32 -0500 Received: from mail-pv0-f174.google.com ([74.125.83.174]:47476 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754075Ab1BSXla (ORCPT ); Sat, 19 Feb 2011 18:41:30 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=E6PbFhj8dvSLUYSo9B8nmnbNZfCHsKIEoesg7015xXoqLV3SiEaxJ1Gfgq2v2J51us WRe9bqBb9vSlgX8beH5hlJzed2Ll9zfJ4pHO8105Wfnk9cGT/EI0HwgT+YDfHzkJDFtT wtsISf6Omv+pC2hJDOzKfVh2joQYk86S1wY5c= Date: Sun, 20 Feb 2011 08:41:21 +0900 From: Minchan Kim To: Andrew Morton Cc: linux-mm , LKML , Miklos Szeredi , Rik van Riel , KAMEZAWA Hiroyuki , Mel Gorman Subject: Re: [PATCH] mm: optimize replace_page_cache_page Message-ID: <20110219234121.GA2546@barrios-desktop> References: <1297355626-5152-1-git-send-email-minchan.kim@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1297355626-5152-1-git-send-email-minchan.kim@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4178 Lines: 128 Resend. he patch is based on mmotm-2011-02-04 + mm-add-replace_page_cache_page-function-add-freepage-hook.patch. On Fri, Feb 11, 2011 at 01:33:46AM +0900, Minchan Kim wrote: > This patch optmizes replace_page_cache_page. > > 1) remove radix_tree_preload > 2) single radix_tree_lookup_slot and replace radix tree slot > 3) page accounting optimization if both pages are in same zone. > > Cc: Miklos Szeredi > Cc: Rik van Riel > Cc: KAMEZAWA Hiroyuki > Cc: Mel Gorman > Signed-off-by: Minchan Kim > --- > mm/filemap.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++--------- > 1 files changed, 51 insertions(+), 10 deletions(-) > > Hi Miklos, > This patch is totally not tested. > Could you test this patch? > > diff --git a/mm/filemap.c b/mm/filemap.c > index a25c898..918ef1e 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -148,6 +148,56 @@ void __remove_from_page_cache(struct page *page) > } > } > > +/* > + * Replace a page from the page cache with a new one. > + * Both the old and new page must be locked. > + * The caller must hold the mapping's tree_lock. > + */ > +void __replace_page_cache_page(struct page *old, struct page *new) > +{ > + void **pslot; > + struct address_space *mapping = old->mapping; > + struct zone *old_zone, *new_zone; > + > + old_zone = page_zone(old); > + new_zone = page_zone(new); > + /* > + * if we're uptodate, flush out into the cleancache, otherwise > + * invalidate any existing cleancache entries. We can't leave > + * stale data around in the cleancache once our page is gone > + */ > + if (PageUptodate(old)) > + cleancache_put_page(old); > + else > + cleancache_flush_page(mapping, old); > + > + pslot = radix_tree_lookup_slot(&mapping->page_tree, > + page_index(old)); > + get_page(new); /* add cache reference */ > + radix_tree_replace_slot(pslot, new); > + old->mapping = NULL; > + if (old_zone != new_zone) { > + __dec_zone_page_state(old, NR_FILE_PAGES); > + __inc_zone_page_state(new, NR_FILE_PAGES); > + if (PageSwapBacked(old)) { > + __dec_zone_page_state(old, NR_SHMEM); > + __inc_zone_page_state(new, NR_SHMEM); > + } > + } > + BUG_ON(page_mapped(old)); > + /* > + * Some filesystems seem to re-dirty the page even after > + * the VM has canceled the dirty bit (eg ext3 journaling). > + * > + * Fix it up by doing a final dirty accounting check after > + * having removed the page entirely. > + */ > + if (PageDirty(old) && mapping_cap_account_dirty(mapping)) { > + dec_zone_page_state(old, NR_FILE_DIRTY); > + dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE); > + } > +} > + > void remove_from_page_cache(struct page *page) > { > struct address_space *mapping = page->mapping; > @@ -433,7 +483,6 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) > if (error) > return error; > > - error = radix_tree_preload(gfp_mask & ~__GFP_HIGHMEM); > if (!error) { > struct address_space *mapping = old->mapping; > void (*freepage)(struct page *); > @@ -441,20 +490,12 @@ int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask) > pgoff_t offset = old->index; > freepage = mapping->a_ops->freepage; > > - page_cache_get(new); > new->mapping = mapping; > new->index = offset; > > spin_lock_irq(&mapping->tree_lock); > - __remove_from_page_cache(old); > - error = radix_tree_insert(&mapping->page_tree, offset, new); > - BUG_ON(error); > - mapping->nrpages++; > - __inc_zone_page_state(new, NR_FILE_PAGES); > - if (PageSwapBacked(new)) > - __inc_zone_page_state(new, NR_SHMEM); > + __replace_page_cache_page(old, new); > spin_unlock_irq(&mapping->tree_lock); > - radix_tree_preload_end(); > if (freepage) > freepage(old); > page_cache_release(old); > -- > 1.7.1 > -- Kind regards, Minchan Kim -- 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/