From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f197.google.com (mail-wr0-f197.google.com [209.85.128.197]) by kanga.kvack.org (Postfix) with ESMTP id A9A446B0006 for ; Fri, 20 Apr 2018 08:01:04 -0400 (EDT) Received: by mail-wr0-f197.google.com with SMTP id a38-v6so8502167wra.10 for ; Fri, 20 Apr 2018 05:01:04 -0700 (PDT) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id l14si14169edc.12.2018.04.20.05.01.02 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 20 Apr 2018 05:01:03 -0700 (PDT) From: Goldwyn Rodrigues Subject: [PATCH v11 19/63] page cache: Convert page deletion to XArray References: <20180414141316.7167-1-willy@infradead.org> <20180414141316.7167-20-willy@infradead.org> Message-ID: <979c1602-42e3-349d-a5e4-d28de14112dd@suse.de> Date: Fri, 20 Apr 2018 07:00:57 -0500 MIME-Version: 1.0 In-Reply-To: <20180414141316.7167-20-willy@infradead.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Cc: Matthew Wilcox , Jan Kara , Jeff Layton , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Nicholas Piggin , Ryusuke Konishi , linux-nilfs@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net, Oleg Drokin , Andreas Dilger , James Simmons , Mike Kravetz On 04/14/2018 09:12 AM, Matthew Wilcox wrote: > From: Matthew Wilcox > > The code is slightly shorter and simpler. > > Signed-off-by: Matthew Wilcox > --- > mm/filemap.c | 30 ++++++++++++++---------------- > 1 file changed, 14 insertions(+), 16 deletions(-) > > diff --git a/mm/filemap.c b/mm/filemap.c > index 070b5e4527ac..4af06a1a9818 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -111,30 +111,28 @@ > * ->tasklist_lock (memory_failure, collect_procs_ao) > */ > > -static void page_cache_tree_delete(struct address_space *mapping, > +static void page_cache_delete(struct address_space *mapping, > struct page *page, void *shadow) > { > - int i, nr; > + XA_STATE(xas, &mapping->i_pages, page->index); > + unsigned int i, nr; > > - /* hugetlb pages are represented by one entry in the radix tree */ > + mapping_set_update(&xas, mapping); > + > + /* hugetlb pages are represented by a single entry in the xarray */ > nr = PageHuge(page) ? 1 : hpage_nr_pages(page); > > VM_BUG_ON_PAGE(!PageLocked(page), page); > VM_BUG_ON_PAGE(PageTail(page), page); > VM_BUG_ON_PAGE(nr != 1 && shadow, page); > > - for (i = 0; i < nr; i++) { > - struct radix_tree_node *node; > - void **slot; > - > - __radix_tree_lookup(&mapping->i_pages, page->index + i, > - &node, &slot); > - > - VM_BUG_ON_PAGE(!node && nr != 1, page); > - > - radix_tree_clear_tags(&mapping->i_pages, node, slot); > - __radix_tree_replace(&mapping->i_pages, node, slot, shadow, > - workingset_lookup_update(mapping)); > + i = nr; > +repeat: > + xas_store(&xas, shadow); > + xas_init_tags(&xas); > + if (--i) { > + xas_next(&xas); > + goto repeat; > } Can this be converted into a do {} while (or even for) loop instead? Loops are easier to read and understand in such a situation. > > page->mapping = NULL; > @@ -234,7 +232,7 @@ void __delete_from_page_cache(struct page *page, void *shadow) > trace_mm_filemap_delete_from_page_cache(page); > > unaccount_page_cache_page(mapping, page); > - page_cache_tree_delete(mapping, page, shadow); > + page_cache_delete(mapping, page, shadow); > } > > static void page_cache_free_page(struct address_space *mapping, > -- Goldwyn