From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 7180C6B0033 for ; Sun, 5 Feb 2017 09:21:04 -0500 (EST) Received: by mail-pf0-f197.google.com with SMTP id 204so80477367pfx.1 for ; Sun, 05 Feb 2017 06:21:04 -0800 (PST) Received: from lgeamrelo11.lge.com (LGEAMRELO11.lge.com. [156.147.23.51]) by mx.google.com with ESMTP id u17si26249085pgn.198.2017.02.05.06.21.02 for ; Sun, 05 Feb 2017 06:21:03 -0800 (PST) Date: Sun, 5 Feb 2017 23:21:00 +0900 From: Minchan Kim 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> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: zhouxianrong@huawei.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, sergey.senozhatsky@gmail.com, willy@infradead.org, iamjoonsoo.kim@lge.com, ngupta@vflare.org, Mi.Sophia.Wang@huawei.com, zhouxiyu@huawei.com, weidu.du@huawei.com, zhangshiming5@huawei.com, won.ho.park@huawei.com 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. -- 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