Re: [PATCH] mmc: block: Add MMC write packing statistics

From: merez
Date: Tue Apr 30 2013 - 16:29:17 EST

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Hi Chris,

Can we push this change to kernel-3.10?

Thanks,
Maya
> The write packing statistics are used for debug purposes, in order
> to get the amount of packing in different scenarios.
> The statistics also include the reason for stopping the creation of
> the packed request.
>
> Signed-off-by: Maya Erez <merez@xxxxxxxxxxxxxx>
>
> diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
> index e12a03c..2dc48ae 100644
> --- a/drivers/mmc/card/block.c
> +++ b/drivers/mmc/card/block.c
> @@ -64,6 +64,11 @@ MODULE_ALIAS("mmc:block");
> (rq_data_dir(req) == WRITE))
> #define PACKED_CMD_VER 0x01
> #define PACKED_CMD_WR 0x02
> +#define MMC_BLK_UPDATE_STOP_REASON(stats, reason) \
> + do { \
> + if (stats->enabled) \
> + stats->pack_stop_reason[reason]++; \
> + } while (0)
>
> static DEFINE_MUTEX(block_mutex);
>
> @@ -1405,6 +1410,35 @@ static inline u8 mmc_calc_packed_hdr_segs(struct
> request_queue *q,
> return nr_segs;
> }
>
> +struct mmc_wr_pack_stats *mmc_blk_get_packed_statistics(struct mmc_card
> *card)
> +{
> + if (!card)
> + return NULL;
> +
> + return &card->wr_pack_stats;
> +}
> +EXPORT_SYMBOL(mmc_blk_get_packed_statistics);
> +
> +void mmc_blk_init_packed_statistics(struct mmc_card *card)
> +{
> + int max_num_of_packed_reqs = 0;
> +
> + if (!card || !card->wr_pack_stats.packing_events)
> + return;
> +
> + max_num_of_packed_reqs = card->ext_csd.max_packed_writes;
> +
> + spin_lock(&card->wr_pack_stats.lock);
> + memset(card->wr_pack_stats.packing_events, 0,
> + (max_num_of_packed_reqs + 1) *
> + sizeof(*card->wr_pack_stats.packing_events));
> + memset(&card->wr_pack_stats.pack_stop_reason, 0,
> + sizeof(card->wr_pack_stats.pack_stop_reason));
> + card->wr_pack_stats.enabled = true;
> + spin_unlock(&card->wr_pack_stats.lock);
> +}
> +EXPORT_SYMBOL(mmc_blk_init_packed_statistics);
> +
> static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request
> *req)
> {
> struct request_queue *q = mq->queue;
> @@ -1418,6 +1452,7 @@ static u8 mmc_blk_prep_packed_list(struct mmc_queue
> *mq, struct request *req)
> bool put_back = true;
> u8 max_packed_rw = 0;
> u8 reqs = 0;
> + struct mmc_wr_pack_stats *stats = &card->wr_pack_stats;
>
> if (!(md->flags & MMC_BLK_PACKED_CMD))
> goto no_packed;
> @@ -1464,31 +1499,44 @@ static u8 mmc_blk_prep_packed_list(struct
> mmc_queue *mq, struct request *req)
> spin_unlock_irq(q->queue_lock);
> if (!next) {
> put_back = false;
> + MMC_BLK_UPDATE_STOP_REASON(stats, EMPTY_QUEUE);
> break;
> }
>
> if (mmc_large_sector(card) &&
> - !IS_ALIGNED(blk_rq_sectors(next), 8))
> + !IS_ALIGNED(blk_rq_sectors(next), 8)) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, LARGE_SEC_ALIGN);
> break;
> + }
>
> if (next->cmd_flags & REQ_DISCARD ||
> - next->cmd_flags & REQ_FLUSH)
> + next->cmd_flags & REQ_FLUSH) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, FLUSH_OR_DISCARD);
> break;
> + }
>
> - if (rq_data_dir(cur) != rq_data_dir(next))
> + if (rq_data_dir(cur) != rq_data_dir(next)) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, WRONG_DATA_DIR);
> break;
> + }
>
> if (mmc_req_rel_wr(next) &&
> - (md->flags & MMC_BLK_REL_WR) && !en_rel_wr)
> + (md->flags & MMC_BLK_REL_WR) && !en_rel_wr) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, REL_WRITE);
> break;
> + }
>
> req_sectors += blk_rq_sectors(next);
> - if (req_sectors > max_blk_count)
> + if (req_sectors > max_blk_count) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, EXCEEDS_SECTORS);
> break;
> + }
>
> phys_segments += next->nr_phys_segments;
> - if (phys_segments > max_phys_segs)
> + if (phys_segments > max_phys_segs) {
> + MMC_BLK_UPDATE_STOP_REASON(stats, EXCEEDS_SEGMENTS);
> break;
> + }
>
> list_add_tail(&next->queuelist, &mqrq->packed->list);
> cur = next;
> @@ -1501,6 +1549,15 @@ static u8 mmc_blk_prep_packed_list(struct mmc_queue
> *mq, struct request *req)
> spin_unlock_irq(q->queue_lock);
> }
>
> + if (stats->enabled) {
> + if (reqs + 1 <= card->ext_csd.max_packed_writes)
> + stats->packing_events[reqs + 1]++;
> + if (reqs + 1 == max_packed_rw)
> + MMC_BLK_UPDATE_STOP_REASON(stats, THRESHOLD);
> + }
> +
> + spin_unlock(&stats->lock);
> +
> if (reqs > 0) {
> list_add(&req->queuelist, &mqrq->packed->list);
> mqrq->packed->nr_entries = ++reqs;
> diff --git a/drivers/mmc/core/bus.c b/drivers/mmc/core/bus.c
> index e219c97..4417bf1 100644
> --- a/drivers/mmc/core/bus.c
> +++ b/drivers/mmc/core/bus.c
> @@ -250,6 +250,8 @@ struct mmc_card *mmc_alloc_card(struct mmc_host *host,
> struct device_type *type)
> card->dev.release = mmc_release_card;
> card->dev.type = type;
>
> + spin_lock_init(&card->wr_pack_stats.lock);
> +
> return card;
> }
>
> @@ -353,6 +355,8 @@ void mmc_remove_card(struct mmc_card *card)
> device_del(&card->dev);
> }
>
> + kfree(card->wr_pack_stats.packing_events);
> +
> put_device(&card->dev);
> }
>
> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
> index 35c2f85..054839d 100644
> --- a/drivers/mmc/core/debugfs.c
> +++ b/drivers/mmc/core/debugfs.c
> @@ -334,6 +334,176 @@ static const struct file_operations
> mmc_dbg_ext_csd_fops = {
> .llseek = default_llseek,
> };
>
> +static int mmc_wr_pack_stats_open(struct inode *inode, struct file *filp)
> +{
> + struct mmc_card *card = inode->i_private;
> +
> + filp->private_data = card;
> + card->wr_pack_stats.print_in_read = 1;
> + return 0;
> +}
> +
> +#define TEMP_BUF_SIZE 256
> +static ssize_t mmc_wr_pack_stats_read(struct file *filp, char __user
> *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + struct mmc_card *card = filp->private_data;
> + struct mmc_wr_pack_stats *pack_stats;
> + int i;
> + int max_num_of_packed_reqs = 0;
> + char *temp_buf;
> +
> + if (!card)
> + return cnt;
> +
> + if (!card->wr_pack_stats.print_in_read)
> + return 0;
> +
> + if (!card->wr_pack_stats.enabled) {
> + pr_info("%s: write packing statistics are disabled\n",
> + mmc_hostname(card->host));
> + goto exit;
> + }
> +
> + pack_stats = &card->wr_pack_stats;
> +
> + if (!pack_stats->packing_events) {
> + pr_info("%s: NULL packing_events\n", mmc_hostname(card->host));
> + goto exit;
> + }
> +
> + max_num_of_packed_reqs = card->ext_csd.max_packed_writes;
> +
> + temp_buf = kmalloc(TEMP_BUF_SIZE, GFP_KERNEL);
> + if (!temp_buf)
> + goto exit;
> +
> + spin_lock(&pack_stats->lock);
> +
> + snprintf(temp_buf, TEMP_BUF_SIZE, "%s: write packing statistics:\n",
> + mmc_hostname(card->host));
> + strlcat(ubuf, temp_buf, cnt);
> +
> + /*
> + * The statistics are kept in the index that equals the number of
> + * packed requests. Therefore we need to print the values in indexes
> + * 1 to max_num_of_packed_reqs.
> + */
> + for (i = 1 ; i <= max_num_of_packed_reqs ; ++i) {
> + if (pack_stats->packing_events[i]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: Packed %d reqs - %d times\n",
> + mmc_hostname(card->host), i,
> + pack_stats->packing_events[i]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + }
> +
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: stopped packing due to the following reasons:\n",
> + mmc_hostname(card->host));
> + strlcat(ubuf, temp_buf, cnt);
> +
> + if (pack_stats->pack_stop_reason[EXCEEDS_SEGMENTS]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: exceed max num of segments\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[EXCEEDS_SEGMENTS]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[EXCEEDS_SECTORS]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: exceed max num of sectors\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[EXCEEDS_SECTORS]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[WRONG_DATA_DIR]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: wrong data direction\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[WRONG_DATA_DIR]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[FLUSH_OR_DISCARD]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: flush or discard\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[FLUSH_OR_DISCARD]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[EMPTY_QUEUE]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: empty queue\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[EMPTY_QUEUE]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[REL_WRITE]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: rel write\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[REL_WRITE]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[THRESHOLD]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: Threshold\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[THRESHOLD]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> + if (pack_stats->pack_stop_reason[LARGE_SEC_ALIGN]) {
> + snprintf(temp_buf, TEMP_BUF_SIZE,
> + "%s: %d times: large sector alignment\n",
> + mmc_hostname(card->host),
> + pack_stats->pack_stop_reason[LARGE_SEC_ALIGN]);
> + strlcat(ubuf, temp_buf, cnt);
> + }
> +
> + spin_unlock(&pack_stats->lock);
> +
> + kfree(temp_buf);
> +
> + pr_info("%s", ubuf);
> +
> +exit:
> + if (card->wr_pack_stats.print_in_read == 1) {
> + card->wr_pack_stats.print_in_read = 0;
> + return strnlen(ubuf, cnt);
> + }
> +
> + return 0;
> +}
> +
> +static ssize_t mmc_wr_pack_stats_write(struct file *filp,
> + const char __user *ubuf, size_t cnt,
> + loff_t *ppos)
> +{
> + struct mmc_card *card = filp->private_data;
> + int value;
> +
> + if (!card)
> + return cnt;
> +
> + sscanf(ubuf, "%d", &value);
> + if (value) {
> + mmc_blk_init_packed_statistics(card);
> + } else {
> + spin_lock(&card->wr_pack_stats.lock);
> + card->wr_pack_stats.enabled = false;
> + spin_unlock(&card->wr_pack_stats.lock);
> + }
> +
> + return cnt;
> +}
> +
> +static const struct file_operations mmc_dbg_wr_pack_stats_fops = {
> + .open = mmc_wr_pack_stats_open,
> + .read = mmc_wr_pack_stats_read,
> + .write = mmc_wr_pack_stats_write,
> +};
> +
> void mmc_add_card_debugfs(struct mmc_card *card)
> {
> struct mmc_host *host = card->host;
> @@ -366,6 +536,12 @@ void mmc_add_card_debugfs(struct mmc_card *card)
> &mmc_dbg_ext_csd_fops))
> goto err;
>
> + if (mmc_card_mmc(card) && (card->ext_csd.rev >= 6) &&
> + (card->host->caps2 & MMC_CAP2_PACKED_WR))
> + if (!debugfs_create_file("wr_pack_stats", S_IRUSR, root, card,
> + &mmc_dbg_wr_pack_stats_fops))
> + goto err;
> +
> return;
>
> err:
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 0cbd1ef..ee8cdf7 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -1304,6 +1304,24 @@ static int mmc_init_card(struct mmc_host *host, u32
> ocr,
> } else {
> card->ext_csd.packed_event_en = 1;
> }
> +
> + }
> +
> + if (!oldcard) {
> + if ((host->caps2 & MMC_CAP2_PACKED_CMD) &&
> + (card->ext_csd.max_packed_writes > 0)) {
> + /*
> + * We would like to keep the statistics in an index
> + * that equals the num of packed requests
> + * (1 to max_packed_writes)
> + */
> + card->wr_pack_stats.packing_events = kzalloc(
> + (card->ext_csd.max_packed_writes + 1) *
> + sizeof(*card->wr_pack_stats.packing_events),
> + GFP_KERNEL);
> + if (!card->wr_pack_stats.packing_events)
> + goto free_card;
> + }
> }
>
> if (!oldcard)
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index f31725b..66732a7 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -226,6 +226,26 @@ struct mmc_part {
> #define MMC_BLK_DATA_AREA_RPMB (1<<3)
> };
>
> +enum mmc_packed_stop_reasons {
> + EXCEEDS_SEGMENTS = 0,
> + EXCEEDS_SECTORS,
> + WRONG_DATA_DIR,
> + FLUSH_OR_DISCARD,
> + EMPTY_QUEUE,
> + REL_WRITE,
> + THRESHOLD,
> + LARGE_SEC_ALIGN,
> + MAX_REASONS,
> +};
> +
> +struct mmc_wr_pack_stats {
> + u32 *packing_events;
> + u32 pack_stop_reason[MAX_REASONS];
> + spinlock_t lock;
> + bool enabled;
> + bool print_in_read;
> +};
> +
> /*
> * MMC device
> */
> @@ -294,6 +314,7 @@ struct mmc_card {
> struct dentry *debugfs_root;
> struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical partitions */
> unsigned int nr_parts;
> + struct mmc_wr_pack_stats wr_pack_stats; /* packed commands stats*/
> };
>
> /*
> @@ -520,4 +541,8 @@ extern void mmc_unregister_driver(struct mmc_driver
> *);
> extern void mmc_fixup_device(struct mmc_card *card,
> const struct mmc_fixup *table);
>
> +extern struct mmc_wr_pack_stats *mmc_blk_get_packed_statistics(
> + struct mmc_card *card);
> +extern void mmc_blk_init_packed_statistics(struct mmc_card *card);
> +
> #endif /* LINUX_MMC_CARD_H */
> --
> 1.7.3.3
> --
> QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

--
Maya Erez
QUALCOMM ISRAEL, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

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Next message: Daniel Vetter: "[PATCH] [RFC] mutex: w/w mutex slowpath debugging"
Previous message: Maya Erez: "[PATCH v4] mmc: card: Adding support for sanitize in eMMC 4.5"
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