From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751829AbdBEOVH (ORCPT ); Sun, 5 Feb 2017 09:21:07 -0500 Received: from LGEAMRELO11.lge.com ([156.147.23.51]:44840 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751261AbdBEOVG (ORCPT ); Sun, 5 Feb 2017 09:21:06 -0500 X-Original-SENDERIP: 156.147.1.121 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 165.244.249.25 X-Original-MAILFROM: minchan@kernel.org X-Original-SENDERIP: 10.177.223.161 X-Original-MAILFROM: minchan@kernel.org Date: Sun, 5 Feb 2017 23:21:00 +0900 From: Minchan Kim To: CC: , , , , , , , , , , , Subject: Re: [PATCH] mm: extend zero pages to same element pages for zram Message-ID: <20170205142100.GA9611@bbox> References: <1483692145-75357-1-git-send-email-zhouxianrong@huawei.com> <1486111347-112972-1-git-send-email-zhouxianrong@huawei.com> MIME-Version: 1.0 In-Reply-To: <1486111347-112972-1-git-send-email-zhouxianrong@huawei.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-MIMETrack: Itemize by SMTP Server on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/02/05 23:20:59, Serialize by Router on LGEKRMHUB03/LGE/LG Group(Release 8.5.3FP6|November 21, 2013) at 2017/02/05 23:21:00, Serialize complete at 2017/02/05 23:21:00 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 Hi zhouxianrong, On Fri, Feb 03, 2017 at 04:42:27PM +0800, zhouxianrong@huawei.com wrote: > From: zhouxianrong > > test result as listed below: > > zero pattern_char pattern_short pattern_int pattern_long total (unit) > 162989 14454 3534 23516 2769 3294399 (page) > > statistics for the result: > > zero pattern_char pattern_short pattern_int pattern_long > AVERAGE 0.745696298 0.085937175 0.015957701 0.131874915 0.020533911 > STDEV 0.035623777 0.016892402 0.004454534 0.021657123 0.019420072 > MAX 0.973813421 0.222222222 0.021409518 0.211812245 0.176512625 > MIN 0.645431905 0.004634398 0 0 0 The description in old version was better for justifying same page merging feature. > > Signed-off-by: zhouxianrong > --- > drivers/block/zram/zram_drv.c | 124 +++++++++++++++++++++++++++++++---------- > drivers/block/zram/zram_drv.h | 11 ++-- > 2 files changed, 103 insertions(+), 32 deletions(-) > > diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c > index e5ab7d9..6a8c9c5 100644 > --- a/drivers/block/zram/zram_drv.c > +++ b/drivers/block/zram/zram_drv.c > @@ -95,6 +95,17 @@ static void zram_clear_flag(struct zram_meta *meta, u32 index, > meta->table[index].value &= ~BIT(flag); > } > > +static inline void zram_set_element(struct zram_meta *meta, u32 index, > + unsigned long element) > +{ > + meta->table[index].element = element; > +} > + > +static inline void zram_clear_element(struct zram_meta *meta, u32 index) > +{ > + meta->table[index].element = 0; > +} > + > static size_t zram_get_obj_size(struct zram_meta *meta, u32 index) > { > return meta->table[index].value & (BIT(ZRAM_FLAG_SHIFT) - 1); > @@ -167,31 +178,78 @@ static inline void update_used_max(struct zram *zram, > } while (old_max != cur_max); > } > > -static bool page_zero_filled(void *ptr) > +static inline void zram_fill_page(char *ptr, unsigned long value) > +{ > + int i; > + unsigned long *page = (unsigned long *)ptr; > + > + if (likely(value == 0)) { > + clear_page(ptr); > + } else { > + for (i = 0; i < PAGE_SIZE / sizeof(*page); i++) > + page[i] = value; > + } > +} > + > +static inline void zram_fill_page_partial(char *ptr, unsigned int size, > + unsigned long value) > +{ > + int i; > + unsigned long *page; > + > + if (likely(value == 0)) { > + memset(ptr, 0, size); > + return; > + } > + > + i = ((unsigned long)ptr) % sizeof(*page); > + if (i) { > + while (i < sizeof(*page)) { > + *ptr++ = (value >> (i * 8)) & 0xff; > + --size; > + ++i; > + } > + } > + I don't think we need this part because block layer works with sector size or multiple times of it so it must be aligned unsigned long.