From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx206.postini.com [74.125.245.206]) by kanga.kvack.org (Postfix) with SMTP id 5D71B6B0002 for ; Mon, 3 Jun 2013 02:13:22 -0400 (EDT) Date: Mon, 3 Jun 2013 15:13:20 +0900 From: Minchan Kim Subject: Re: [v4][PATCH 2/6] mm: swap: make 'struct page' and swp_entry_t variants of swapcache_free(). Message-ID: <20130603061320.GA2795@blaptop> References: <20130531183855.44DDF928@viggo.jf.intel.com> <20130531183858.3C8C10C7@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130531183858.3C8C10C7@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, mgorman@suse.de, tim.c.chen@linux.intel.com Hello Dave, On Fri, May 31, 2013 at 11:38:58AM -0700, Dave Hansen wrote: > > From: Dave Hansen > > swapcache_free() takes two arguments: > > void swapcache_free(swp_entry_t entry, struct page *page) > > Most of its callers (5/7) are from error handling paths haven't even > instantiated a page, so they pass page=NULL. Both of the callers > that call in with a 'struct page' create and pass in a temporary > swp_entry_t. > > Now that we are deferring clearing page_private() until after > swapcache_free() has been called, we can just create a variant > that takes a 'struct page' and does the temporary variable in > the helper. > > That leaves all the other callers doing > > swapcache_free(entry, NULL) > > so create another helper for them that makes it clear that they > need only pass in a swp_entry_t. > > One downside here is that delete_from_swap_cache() now does > an extra swap_address_space() call. But, those are pretty > cheap (just some array index arithmetic). I lost from this description. Old behavior delete_from_swap_cache swap_address_space __delete_from_swap_cache swap_address_space New behavior delete_from_swap_cache __delete_from_swap_cache swap_address_space So you removes a swap_address_space, not adding a extra call. Am I missing something? > > Signed-off-by: Dave Hansen Otherwise, looks good to me Reviewed-by: Minchan Kim -- Kind regards, Minchan Kim -- 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