From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932330AbcGCX40 (ORCPT ); Sun, 3 Jul 2016 19:56:26 -0400 Received: from LGEAMRELO13.lge.com ([156.147.23.53]:46829 "EHLO lgeamrelo13.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932198AbcGCX4Y (ORCPT ); Sun, 3 Jul 2016 19:56:24 -0400 X-Original-SENDERIP: 156.147.1.151 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 165.244.98.76 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Mon, 4 Jul 2016 08:57:04 +0900 From: Minchan Kim To: Ganesh Mahendran CC: , , , , , , Subject: Re: [PATCH 3/8] mm/zsmalloc: take obj index back from find_alloced_obj Message-ID: <20160703235704.GB19044@bbox> References: <1467355266-9735-1-git-send-email-opensource.ganesh@gmail.com> <1467355266-9735-3-git-send-email-opensource.ganesh@gmail.com> MIME-Version: 1.0 In-Reply-To: <1467355266-9735-3-git-send-email-opensource.ganesh@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB08/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/04 08:56:21, Serialize by Router on LGEKRMHUB08/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2016/07/04 08:56:21, Serialize complete at 2016/07/04 08:56:21 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 01, 2016 at 02:41:01PM +0800, Ganesh Mahendran wrote: > the obj index value should be updated after return from > find_alloced_obj() to avoid CPU buring caused by unnecessary object scanning. Description should include what's the goal. > > Signed-off-by: Ganesh Mahendran > --- > mm/zsmalloc.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c > index 405baa5..5c96ed1 100644 > --- a/mm/zsmalloc.c > +++ b/mm/zsmalloc.c > @@ -1744,15 +1744,16 @@ static void zs_object_copy(struct size_class *class, unsigned long dst, > * return handle. > */ > static unsigned long find_alloced_obj(struct size_class *class, > - struct page *page, int index) > + struct page *page, int *index) > { > unsigned long head; > int offset = 0; > + int objidx = *index; Nit: We have used obj_idx so I prefer it for consistency with others. Suggestion: Could you mind changing index in zs_compact_control and migrate_zspage with obj_idx in this chance? Strictly speaking, such clean up is separate patch but I don't mind mixing them here(Of course, you will send it as another clean up patch, it would be better). If you mind, just let it leave as is. Sometime, I wil do it. > unsigned long handle = 0; > void *addr = kmap_atomic(page); > > offset = get_first_obj_offset(page); > - offset += class->size * index; > + offset += class->size * objidx; > > while (offset < PAGE_SIZE) { > head = obj_to_head(page, addr + offset); > @@ -1764,9 +1765,11 @@ static unsigned long find_alloced_obj(struct size_class *class, > } > > offset += class->size; > - index++; > + objidx++; > } > > + *index = objidx; We can do this out of kmap section right before returing handle. Thanks! > + > kunmap_atomic(addr); > return handle; > } > @@ -1794,11 +1797,11 @@ static int migrate_zspage(struct zs_pool *pool, struct size_class *class, > unsigned long handle; > struct page *s_page = cc->s_page; > struct page *d_page = cc->d_page; > - unsigned long index = cc->index; > + unsigned int index = cc->index; > int ret = 0; > > while (1) { > - handle = find_alloced_obj(class, s_page, index); > + handle = find_alloced_obj(class, s_page, &index); > if (!handle) { > s_page = get_next_page(s_page); > if (!s_page) > -- > 1.9.1 >