From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753985Ab3BDCCF (ORCPT ); Sun, 3 Feb 2013 21:02:05 -0500 Received: from mail-da0-f43.google.com ([209.85.210.43]:47555 "EHLO mail-da0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753728Ab3BDCCC (ORCPT ); Sun, 3 Feb 2013 21:02:02 -0500 Date: Sun, 3 Feb 2013 18:01:53 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Johannes Weiner cc: Andrew Morton , Konstantin Khlebnikov , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [patch] mm: shmem: use new radix tree iterator In-Reply-To: <1359699238-7327-1-git-send-email-hannes@cmpxchg.org> Message-ID: References: <1359699238-7327-1-git-send-email-hannes@cmpxchg.org> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 1 Feb 2013, Johannes Weiner wrote: > In shmem_find_get_pages_and_swap, use the faster radix tree iterator > construct from 78c1d78 "radix-tree: introduce bit-optimized iterator". > > Signed-off-by: Johannes Weiner Yes, that looks fine, and is testing out fine, thanks. Acked-by: Hugh Dickins > --- > mm/shmem.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index a368a1c..c5dc8ae 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -336,19 +336,19 @@ static unsigned shmem_find_get_pages_and_swap(struct address_space *mapping, > pgoff_t start, unsigned int nr_pages, > struct page **pages, pgoff_t *indices) > { > - unsigned int i; > - unsigned int ret; > - unsigned int nr_found; > + void **slot; > + unsigned int ret = 0; > + struct radix_tree_iter iter; > + > + if (!nr_pages) > + return 0; > > rcu_read_lock(); > restart: > - nr_found = radix_tree_gang_lookup_slot(&mapping->page_tree, > - (void ***)pages, indices, start, nr_pages); > - ret = 0; > - for (i = 0; i < nr_found; i++) { > + radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { > struct page *page; > repeat: > - page = radix_tree_deref_slot((void **)pages[i]); > + page = radix_tree_deref_slot(slot); > if (unlikely(!page)) > continue; > if (radix_tree_exception(page)) { > @@ -365,17 +365,16 @@ static unsigned shmem_find_get_pages_and_swap(struct address_space *mapping, > goto repeat; > > /* Has the page moved? */ > - if (unlikely(page != *((void **)pages[i]))) { > + if (unlikely(page != *slot)) { > page_cache_release(page); > goto repeat; > } > export: > - indices[ret] = indices[i]; > + indices[ret] = iter.index; > pages[ret] = page; > - ret++; > + if (++ret == nr_pages) > + break; > } > - if (unlikely(!ret && nr_found)) > - goto restart; > rcu_read_unlock(); > return ret; > } > -- > 1.7.11.7