From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by kanga.kvack.org (Postfix) with ESMTP id 29F4F6B0035 for ; Fri, 22 Aug 2014 04:22:26 -0400 (EDT) Received: by mail-pa0-f49.google.com with SMTP id hz1so15848892pad.8 for ; Fri, 22 Aug 2014 01:22:25 -0700 (PDT) Received: from mailout1.samsung.com (mailout1.samsung.com. [203.254.224.24]) by mx.google.com with ESMTPS id x6si91585pas.223.2014.08.22.01.22.24 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Fri, 22 Aug 2014 01:22:24 -0700 (PDT) Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0NAP005DW8KYRGB0@mailout1.samsung.com> for linux-mm@kvack.org; Fri, 22 Aug 2014 17:22:10 +0900 (KST) From: Chao Yu Subject: [PATCH v3] zram: add num_discards for discarded pages stat Date: Fri, 22 Aug 2014 16:21:01 +0800 Message-id: <000201cfbde2$2ae08710$80a19530$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit Content-language: zh-cn Sender: owner-linux-mm@kvack.org List-ID: To: minchan@kernel.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, ngupta@vflare.org, 'Jerome Marchand' , 'Sergey Senozhatsky' , 'Andrew Morton' Since we have supported handling discard request in this commit f4659d8e620d08bd1a84a8aec5d2f5294a242764 (zram: support REQ_DISCARD), zram got one more chance to free unused memory whenever received discard request. But without stating for discard request, there is no method for user to know whether discard request has been handled by zram or how many blocks were discarded by zram when user wants to know the effect of discard. In this patch, we add num_discards to stat discarded pages, and export it to sysfs for users. * From v1 * Update zram document to show num_discards in statistics list. * From v2 * Update description of this patch with clear goal. Signed-off-by: Chao Yu --- Documentation/ABI/testing/sysfs-block-zram | 10 ++++++++++ Documentation/blockdev/zram.txt | 1 + drivers/block/zram/zram_drv.c | 3 +++ drivers/block/zram/zram_drv.h | 1 + 4 files changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index 70ec992..fa8936e 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -57,6 +57,16 @@ Description: The failed_writes file is read-only and specifies the number of failed writes happened on this device. + +What: /sys/block/zram/num_discards +Date: August 2014 +Contact: Chao Yu +Description: + The num_discards file is read-only and specifies the number of + physical blocks which are discarded by this device. These blocks + are included in discard request which is sended by filesystem as + the blocks are no longer used. + What: /sys/block/zram/max_comp_streams Date: February 2014 Contact: Sergey Senozhatsky diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 0595c3f..e50e18b 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -89,6 +89,7 @@ size of the disk when not in use so a huge zram is wasteful. num_writes failed_reads failed_writes + num_discards invalid_io notify_free zero_pages diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index d00831c..904e7a5 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -606,6 +606,7 @@ static void zram_bio_discard(struct zram *zram, u32 index, bit_spin_lock(ZRAM_ACCESS, &meta->table[index].value); zram_free_page(zram, index); bit_spin_unlock(ZRAM_ACCESS, &meta->table[index].value); + atomic64_inc(&zram->stats.num_discards); index++; n -= PAGE_SIZE; } @@ -866,6 +867,7 @@ ZRAM_ATTR_RO(num_reads); ZRAM_ATTR_RO(num_writes); ZRAM_ATTR_RO(failed_reads); ZRAM_ATTR_RO(failed_writes); +ZRAM_ATTR_RO(num_discards); ZRAM_ATTR_RO(invalid_io); ZRAM_ATTR_RO(notify_free); ZRAM_ATTR_RO(zero_pages); @@ -879,6 +881,7 @@ static struct attribute *zram_disk_attrs[] = { &dev_attr_num_writes.attr, &dev_attr_failed_reads.attr, &dev_attr_failed_writes.attr, + &dev_attr_num_discards.attr, &dev_attr_invalid_io.attr, &dev_attr_notify_free.attr, &dev_attr_zero_pages.attr, diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index e0f725c..2994aaf 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -86,6 +86,7 @@ struct zram_stats { atomic64_t num_writes; /* --do-- */ atomic64_t failed_reads; /* can happen when memory is too low */ atomic64_t failed_writes; /* can happen when memory is too low */ + atomic64_t num_discards; /* no. of discarded pages */ atomic64_t invalid_io; /* non-page-aligned I/O requests */ atomic64_t notify_free; /* no. of swap slot free notifications */ atomic64_t zero_pages; /* no. of zero filled pages */ -- 2.0.1.474.g72c7794 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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