Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753343Ab0HIR1I (ORCPT ); Mon, 9 Aug 2010 13:27:08 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:60296 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752978Ab0HIR07 (ORCPT ); Mon, 9 Aug 2010 13:26:59 -0400 From: Nitin Gupta To: Pekka Enberg , Minchan Kim , Andrew Morton , Greg KH Cc: Linux Driver Project , linux-mm , linux-kernel Subject: [PATCH 03/10] Use percpu stats Date: Mon, 9 Aug 2010 22:56:49 +0530 Message-Id: <1281374816-904-4-git-send-email-ngupta@vflare.org> X-Mailer: git-send-email 1.7.2.1 In-Reply-To: <1281374816-904-1-git-send-email-ngupta@vflare.org> References: <1281374816-904-1-git-send-email-ngupta@vflare.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13028 Lines: 412 Also remove references to removed stats (ex: good_comress). Signed-off-by: Nitin Gupta --- drivers/staging/zram/zram_drv.c | 77 ++++++++++++++++-------------------- drivers/staging/zram/zram_drv.h | 33 +++++++++------- drivers/staging/zram/zram_sysfs.c | 46 +++++++++++++++------- 3 files changed, 84 insertions(+), 72 deletions(-) diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c index c5f84ee..f111b86 100644 --- a/drivers/staging/zram/zram_drv.c +++ b/drivers/staging/zram/zram_drv.c @@ -38,33 +38,27 @@ struct zram *devices; /* Module params (documentation at end) */ unsigned int num_devices; -static void zram_stat_inc(u32 *v) +static void zram_add_stat(struct zram *zram, + enum zram_stats_index idx, s64 val) { - *v = *v + 1; + struct zram_stats_cpu *stats; + + preempt_disable(); + stats = __this_cpu_ptr(zram->stats); + u64_stats_update_begin(&stats->syncp); + stats->count[idx] += val; + u64_stats_update_end(&stats->syncp); + preempt_enable(); } -static void zram_stat_dec(u32 *v) +static void zram_inc_stat(struct zram *zram, enum zram_stats_index idx) { - *v = *v - 1; + zram_add_stat(zram, idx, 1); } -static void zram_stat64_add(struct zram *zram, u64 *v, u64 inc) +static void zram_dec_stat(struct zram *zram, enum zram_stats_index idx) { - spin_lock(&zram->stat64_lock); - *v = *v + inc; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_sub(struct zram *zram, u64 *v, u64 dec) -{ - spin_lock(&zram->stat64_lock); - *v = *v - dec; - spin_unlock(&zram->stat64_lock); -} - -static void zram_stat64_inc(struct zram *zram, u64 *v) -{ - zram_stat64_add(zram, v, 1); + zram_add_stat(zram, idx, -1); } static int zram_test_flag(struct zram *zram, u32 index, @@ -131,7 +125,7 @@ static void zram_set_disksize(struct zram *zram, size_t totalram_bytes) static void zram_free_page(struct zram *zram, size_t index) { - u32 clen; + int clen; void *obj; struct page *page = zram->table[index].page; @@ -144,7 +138,7 @@ static void zram_free_page(struct zram *zram, size_t index) */ if (zram_test_flag(zram, index, ZRAM_ZERO)) { zram_clear_flag(zram, index, ZRAM_ZERO); - zram_stat_dec(&zram->stats.pages_zero); + zram_dec_stat(zram, ZRAM_STAT_PAGES_ZERO); } return; } @@ -153,7 +147,7 @@ static void zram_free_page(struct zram *zram, size_t index) clen = PAGE_SIZE; __free_page(page); zram_clear_flag(zram, index, ZRAM_UNCOMPRESSED); - zram_stat_dec(&zram->stats.pages_expand); + zram_dec_stat(zram, ZRAM_STAT_PAGES_EXPAND); goto out; } @@ -162,12 +156,10 @@ static void zram_free_page(struct zram *zram, size_t index) kunmap_atomic(obj, KM_USER0); xv_free(zram->mem_pool, page, offset); - if (clen <= PAGE_SIZE / 2) - zram_stat_dec(&zram->stats.good_compress); out: - zram_stat64_sub(zram, &zram->stats.compr_size, clen); - zram_stat_dec(&zram->stats.pages_stored); + zram_add_stat(zram, ZRAM_STAT_COMPR_SIZE, -clen); + zram_dec_stat(zram, ZRAM_STAT_PAGES_STORED); zram->table[index].page = NULL; zram->table[index].offset = 0; @@ -213,7 +205,7 @@ static int zram_read(struct zram *zram, struct bio *bio) return 0; } - zram_stat64_inc(zram, &zram->stats.num_reads); + zram_inc_stat(zram, ZRAM_STAT_NUM_READS); index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; bio_for_each_segment(bvec, bio, i) { @@ -262,7 +254,6 @@ static int zram_read(struct zram *zram, struct bio *bio) if (unlikely(ret != LZO_E_OK)) { pr_err("Decompression failed! err=%d, page=%u\n", ret, index); - zram_stat64_inc(zram, &zram->stats.failed_reads); goto out; } @@ -291,7 +282,7 @@ static int zram_write(struct zram *zram, struct bio *bio) goto out; } - zram_stat64_inc(zram, &zram->stats.num_writes); + zram_inc_stat(zram, ZRAM_STAT_NUM_WRITES); index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; bio_for_each_segment(bvec, bio, i) { @@ -318,7 +309,7 @@ static int zram_write(struct zram *zram, struct bio *bio) if (page_zero_filled(user_mem)) { kunmap_atomic(user_mem, KM_USER0); mutex_unlock(&zram->lock); - zram_stat_inc(&zram->stats.pages_zero); + zram_inc_stat(zram, ZRAM_STAT_PAGES_ZERO); zram_set_flag(zram, index, ZRAM_ZERO); continue; } @@ -331,7 +322,6 @@ static int zram_write(struct zram *zram, struct bio *bio) if (unlikely(ret != LZO_E_OK)) { mutex_unlock(&zram->lock); pr_err("Compression failed! err=%d\n", ret); - zram_stat64_inc(zram, &zram->stats.failed_writes); goto out; } @@ -347,14 +337,12 @@ static int zram_write(struct zram *zram, struct bio *bio) mutex_unlock(&zram->lock); pr_info("Error allocating memory for " "incompressible page: %u\n", index); - zram_stat64_inc(zram, - &zram->stats.failed_writes); goto out; } offset = 0; zram_set_flag(zram, index, ZRAM_UNCOMPRESSED); - zram_stat_inc(&zram->stats.pages_expand); + zram_inc_stat(zram, ZRAM_STAT_PAGES_EXPAND); zram->table[index].page = page_store; src = kmap_atomic(page, KM_USER0); goto memstore; @@ -366,7 +354,6 @@ static int zram_write(struct zram *zram, struct bio *bio) mutex_unlock(&zram->lock); pr_info("Error allocating memory for compressed " "page: %u, size=%zu\n", index, clen); - zram_stat64_inc(zram, &zram->stats.failed_writes); goto out; } @@ -392,10 +379,8 @@ memstore: kunmap_atomic(src, KM_USER0); /* Update stats */ - zram_stat64_add(zram, &zram->stats.compr_size, clen); - zram_stat_inc(&zram->stats.pages_stored); - if (clen <= PAGE_SIZE / 2) - zram_stat_inc(&zram->stats.good_compress); + zram_add_stat(zram, ZRAM_STAT_COMPR_SIZE, clen); + zram_inc_stat(zram, ZRAM_STAT_PAGES_STORED); mutex_unlock(&zram->lock); index++; @@ -436,7 +421,7 @@ static int zram_make_request(struct request_queue *queue, struct bio *bio) struct zram *zram = queue->queuedata; if (!valid_io_request(zram, bio)) { - zram_stat64_inc(zram, &zram->stats.invalid_io); + zram_inc_stat(zram, ZRAM_STAT_INVALID_IO); bio_io_error(bio); return 0; } @@ -542,6 +527,13 @@ int zram_init_device(struct zram *zram) /* zram devices sort of resembles non-rotational disks */ queue_flag_set_unlocked(QUEUE_FLAG_NONROT, zram->disk->queue); + zram->stats = alloc_percpu(struct zram_stats_cpu); + if (!zram->stats) { + pr_err("Error allocating percpu stats\n"); + ret = -ENOMEM; + goto fail; + } + zram->mem_pool = xv_create_pool(); if (!zram->mem_pool) { pr_err("Error creating memory pool\n"); @@ -569,7 +561,7 @@ void zram_slot_free_notify(struct block_device *bdev, unsigned long index) zram = bdev->bd_disk->private_data; zram_free_page(zram, index); - zram_stat64_inc(zram, &zram->stats.notify_free); + zram_inc_stat(zram, ZRAM_STAT_NOTIFY_FREE); } static const struct block_device_operations zram_devops = { @@ -583,7 +575,6 @@ static int create_device(struct zram *zram, int device_id) mutex_init(&zram->lock); mutex_init(&zram->init_lock); - spin_lock_init(&zram->stat64_lock); zram->queue = blk_alloc_queue(GFP_KERNEL); if (!zram->queue) { diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h index a481551..88fddb4 100644 --- a/drivers/staging/zram/zram_drv.h +++ b/drivers/staging/zram/zram_drv.h @@ -15,8 +15,8 @@ #ifndef _ZRAM_DRV_H_ #define _ZRAM_DRV_H_ -#include #include +#include #include "xvmalloc.h" @@ -83,18 +83,22 @@ struct table { u8 flags; } __attribute__((aligned(4))); -struct zram_stats { - u64 compr_size; /* compressed size of pages stored */ - u64 num_reads; /* failed + successful */ - u64 num_writes; /* --do-- */ - u64 failed_reads; /* should NEVER! happen */ - u64 failed_writes; /* can happen when memory is too low */ - u64 invalid_io; /* non-page-aligned I/O requests */ - u64 notify_free; /* no. of swap slot free notifications */ - u32 pages_zero; /* no. of zero filled pages */ - u32 pages_stored; /* no. of pages currently stored */ - u32 good_compress; /* % of pages with compression ratio<=50% */ - u32 pages_expand; /* % of incompressible pages */ +enum zram_stats_index { + ZRAM_STAT_COMPR_SIZE, /* compressed size of pages stored */ + ZRAM_STAT_NUM_READS, /* failed + successful */ + ZRAM_STAT_NUM_WRITES, /* --do-- */ + ZRAM_STAT_INVALID_IO, /* non-page-aligned I/O requests */ + ZRAM_STAT_NOTIFY_FREE, /* no. of swap slot free notifications */ + ZRAM_STAT_DISCARD, /* no. of block discard requests */ + ZRAM_STAT_PAGES_ZERO, /* no. of zero filled pages */ + ZRAM_STAT_PAGES_STORED, /* no. of pages currently stored */ + ZRAM_STAT_PAGES_EXPAND, /* no. of incompressible pages */ + ZRAM_STAT_NSTATS, +}; + +struct zram_stats_cpu { + s64 count[ZRAM_STAT_NSTATS]; + struct u64_stats_sync syncp; }; struct zram { @@ -102,7 +106,6 @@ struct zram { void *compress_workmem; void *compress_buffer; struct table *table; - spinlock_t stat64_lock; /* protect 64-bit stats */ struct mutex lock; /* protect compression buffers against * concurrent writes */ struct request_queue *queue; @@ -116,7 +119,7 @@ struct zram { */ u64 disksize; /* bytes */ - struct zram_stats stats; + struct zram_stats_cpu *stats; }; extern struct zram *devices; diff --git a/drivers/staging/zram/zram_sysfs.c b/drivers/staging/zram/zram_sysfs.c index 6c574a9..43bcdd4 100644 --- a/drivers/staging/zram/zram_sysfs.c +++ b/drivers/staging/zram/zram_sysfs.c @@ -19,14 +19,30 @@ #ifdef CONFIG_SYSFS -static u64 zram_stat64_read(struct zram *zram, u64 *v) +/* + * Individual percpu values can go negative but the sum across all CPUs + * must always be positive (we store various counts). So, return sum as + * unsigned value. + */ +static u64 zram_get_stat(struct zram *zram, enum zram_stats_index idx) { - u64 val; - - spin_lock(&zram->stat64_lock); - val = *v; - spin_unlock(&zram->stat64_lock); + int cpu; + s64 val = 0; + + for_each_possible_cpu(cpu) { + s64 temp; + unsigned int start; + struct zram_stats_cpu *stats; + + stats = per_cpu_ptr(zram->stats, cpu); + do { + start = u64_stats_fetch_begin(&stats->syncp); + temp = stats->count[idx]; + } while (u64_stats_fetch_retry(&stats->syncp, start)); + val += temp; + } + WARN_ON(val < 0); return val; } @@ -119,7 +135,7 @@ static ssize_t num_reads_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_reads)); + zram_get_stat(zram, ZRAM_STAT_NUM_READS)); } static ssize_t num_writes_show(struct device *dev, @@ -128,7 +144,7 @@ static ssize_t num_writes_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.num_writes)); + zram_get_stat(zram, ZRAM_STAT_NUM_WRITES)); } static ssize_t invalid_io_show(struct device *dev, @@ -137,7 +153,7 @@ static ssize_t invalid_io_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.invalid_io)); + zram_get_stat(zram, ZRAM_STAT_INVALID_IO)); } static ssize_t notify_free_show(struct device *dev, @@ -146,7 +162,7 @@ static ssize_t notify_free_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.notify_free)); + zram_get_stat(zram, ZRAM_STAT_NOTIFY_FREE)); } static ssize_t zero_pages_show(struct device *dev, @@ -154,7 +170,8 @@ static ssize_t zero_pages_show(struct device *dev, { struct zram *zram = dev_to_zram(dev); - return sprintf(buf, "%u\n", zram->stats.pages_zero); + return sprintf(buf, "%llu\n", + zram_get_stat(zram, ZRAM_STAT_PAGES_ZERO)); } static ssize_t orig_data_size_show(struct device *dev, @@ -163,7 +180,7 @@ static ssize_t orig_data_size_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - (u64)(zram->stats.pages_stored) << PAGE_SHIFT); + zram_get_stat(zram, ZRAM_STAT_PAGES_STORED) << PAGE_SHIFT); } static ssize_t compr_data_size_show(struct device *dev, @@ -172,7 +189,7 @@ static ssize_t compr_data_size_show(struct device *dev, struct zram *zram = dev_to_zram(dev); return sprintf(buf, "%llu\n", - zram_stat64_read(zram, &zram->stats.compr_size)); + zram_get_stat(zram, ZRAM_STAT_COMPR_SIZE)); } static ssize_t mem_used_total_show(struct device *dev, @@ -183,7 +200,8 @@ static ssize_t mem_used_total_show(struct device *dev, if (zram->init_done) { val = xv_get_total_size_bytes(zram->mem_pool) + - ((u64)(zram->stats.pages_expand) << PAGE_SHIFT); + (zram_get_stat(zram, ZRAM_STAT_PAGES_EXPAND) + << PAGE_SHIFT); } return sprintf(buf, "%llu\n", val); -- 1.7.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/