Messages in this thread Patch in this message | | | From | Minchan Kim <> | Subject | [PATCH 5/6] zram: add bd_stat statistics | Date | Fri, 16 Nov 2018 16:20:34 +0900 |
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bd_stat reprenents things happened in backing device. Currently, it supports bd_counts, bd_reads and bd_writes which are helpful to understand wearout of flash and memory saving.
Signed-off-by: Minchan Kim <minchan@kernel.org> --- Documentation/ABI/testing/sysfs-block-zram | 8 ++++++ Documentation/blockdev/zram.txt | 11 ++++++++ drivers/block/zram/zram_drv.c | 31 ++++++++++++++++++++++ drivers/block/zram/zram_drv.h | 5 ++++ 4 files changed, 55 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-block-zram b/Documentation/ABI/testing/sysfs-block-zram index d1f80b077885..a4daca7e5043 100644 --- a/Documentation/ABI/testing/sysfs-block-zram +++ b/Documentation/ABI/testing/sysfs-block-zram @@ -113,3 +113,11 @@ Contact: Minchan Kim <minchan@kernel.org> Description: The writeback file is write-only and trigger idle and/or huge page writeback to backing device. + +What: /sys/block/zram<id>/bd_stat +Date: November 2018 +Contact: Minchan Kim <minchan@kernel.org> +Description: + The bd_stat file is read-only and represents backing device's + statistics (bd_count, bd_reads, bd_writes.) in a format + similar to block layer statistics file format. diff --git a/Documentation/blockdev/zram.txt b/Documentation/blockdev/zram.txt index 60b585dab6e0..1f4907307a0d 100644 --- a/Documentation/blockdev/zram.txt +++ b/Documentation/blockdev/zram.txt @@ -221,6 +221,17 @@ The stat file represents device's mm statistics. It consists of a single pages_compacted the number of pages freed during compaction huge_pages the number of incompressible pages +File /sys/block/zram<id>/bd_stat + +The stat file represents device's backing device statistics. It consists of +a single line of text and contains the following stats separated by whitespace: + bd_count size of data written in backing device. + Unit: pages + bd_reads the number of reads from backing device + Unit: pages + bd_writes the number of writes to backing device + Unit: pages + 9) Deactivate: swapoff /dev/zram0 umount /dev/zram1 diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index b7b5c9e5f0cd..17d566d9a321 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -505,6 +505,8 @@ static unsigned long alloc_block_bdev(struct zram *zram) ret = blk_idx; out: spin_unlock_irq(&zram->bitmap_lock); + if (ret != 0) + atomic64_inc(&zram->stats.bd_count); return ret; } @@ -518,6 +520,7 @@ static void free_block_bdev(struct zram *zram, unsigned long blk_idx) was_set = test_and_clear_bit(blk_idx, zram->bitmap); spin_unlock_irqrestore(&zram->bitmap_lock, flags); WARN_ON_ONCE(!was_set); + atomic64_dec(&zram->stats.bd_count); } static void zram_page_end_io(struct bio *bio) @@ -661,6 +664,7 @@ static ssize_t writeback_store(struct device *dev, continue; } + atomic64_inc(&zram->stats.bd_writes); /* * We released zram_slot_lock so need to check if the slot was * changed. If there is freeing for the slot, we can catch it @@ -748,6 +752,7 @@ static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec, static int read_from_bdev(struct zram *zram, struct bio_vec *bvec, unsigned long entry, struct bio *parent, bool sync) { + atomic64_inc(&zram->stats.bd_reads); if (sync) return read_from_bdev_sync(zram, bvec, entry, parent); else @@ -790,6 +795,7 @@ static int write_to_bdev(struct zram *zram, struct bio_vec *bvec, submit_bio(bio); *pentry = entry; + atomic64_inc(&zram->stats.bd_writes); return 0; } @@ -1053,6 +1059,25 @@ static ssize_t mm_stat_show(struct device *dev, return ret; } +#ifdef CONFIG_ZRAM_WRITEBACK +static ssize_t bd_stat_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zram *zram = dev_to_zram(dev); + ssize_t ret; + + down_read(&zram->init_lock); + ret = scnprintf(buf, PAGE_SIZE, + "%8llu %8llu %8llu\n", + (u64)atomic64_read(&zram->stats.bd_count), + (u64)atomic64_read(&zram->stats.bd_reads), + (u64)atomic64_read(&zram->stats.bd_writes)); + up_read(&zram->init_lock); + + return ret; +} +#endif + static ssize_t debug_stat_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -1073,6 +1098,9 @@ static ssize_t debug_stat_show(struct device *dev, static DEVICE_ATTR_RO(io_stat); static DEVICE_ATTR_RO(mm_stat); +#ifdef CONFIG_ZRAM_WRITEBACK +static DEVICE_ATTR_RO(bd_stat); +#endif static DEVICE_ATTR_RO(debug_stat); static void zram_meta_free(struct zram *zram, u64 disksize) @@ -1813,6 +1841,9 @@ static struct attribute *zram_disk_attrs[] = { #endif &dev_attr_io_stat.attr, &dev_attr_mm_stat.attr, +#ifdef CONFIG_ZRAM_WRITEBACK + &dev_attr_bd_stat.attr, +#endif &dev_attr_debug_stat.attr, NULL, }; diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h index 07695fe70e17..487ff283fb31 100644 --- a/drivers/block/zram/zram_drv.h +++ b/drivers/block/zram/zram_drv.h @@ -82,6 +82,11 @@ struct zram_stats { atomic_long_t max_used_pages; /* no. of maximum pages stored */ atomic64_t writestall; /* no. of write slow paths */ atomic64_t miss_free; /* no. of missed free */ +#ifdef CONFIG_ZRAM_WRITEBACK + atomic64_t bd_count; /* no. of pages in backing device */ + atomic64_t bd_reads; /* no. of read from backing device */ + atomic64_t bd_writes; /* no. of write from backing device */ +#endif }; struct zram { -- 2.19.1.1215.g8438c0b245-goog
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