Hi Chris,
Do you have any concerns about this patch? Or another advice?
Thanks.
-----Original Message-----
From: Liu Qiang-B32616
Sent: Wednesday, December 21, 2011 3:10 PM
To: cjb@xxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx
Cc: Li Yang-R58472; Liu Qiang-B32616; Liu Qiang-B32616
Subject: [PATCH V2 1/2] SD/MMC: add an interface to re-initialize bounce buffer
Add bounce_size under /sys/block/mmcblk0/bouncesz.
Support dynamic adjustment of bounce buffer in run-time (include mounted or unmounted filesystem).
/sys/block/mmcblk0/bouncesz should be integer multiple of 512, the value should be range from 4096 to 4194304.
1. use variable instead of MMC_QUEUE_BOUNCESZ; 2. Re-initialize bounce buffer accorinding to new bounce size at run-time;
Signed-off-by: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
---
changes for V2
merge former 2 patches to 1
Here is the test results with different mmc bounce size, IOzone is used to test performance of mass data transmission.
Environment:
PowerPC P1022DS platform, Sandisk Class 10, 4G memory card, EXT4 filesystem
[root@p2020ds root]# cat /sys/fs/ block/mmcblk0/bouncesz
65536
[root@p2020ds root]# mount /dev/mmcblk0p1 /mnt/ EXT4-fs (mmcblk0p1): mounted filesystem without journal. Opts:
[root@p2020ds root]# iozone -Rab result -i0 -i1 -r64 =- -n1g -g4g -f /mnt/ff ........
KB reclen write rewrite read reread
1048576 64 14229 13286 662028 663372
2097152 64 13758 12605 49549 47443
4194304 64 13435 12215 21974 22096
........
[root@p2020ds root]# echo 262144 > /sys/block/mmcblk0/bouncesz [root@p2020ds root]# cat /sys/block/mmcblk0/bouncesz
262144
[root@p2020ds root]# iozone -Rab result -i0 -i1 -r64 -n1g -g4g -f /mnt/ff ........
KB reclen write rewrite read reread
1048576 64 19228 19416 676659 677785
2097152 64 18512 18499 26978 27055
4194304 64 17932 18185 21945 21805
........
[root@p2020ds root]# echo 8192 > /sys/block/mmcblk0/bouncesz [root@p2020ds root]# cat /sys/block/mmcblk0/bouncesz
8192
[root@p2020ds root]# iozone -Rab result -i0 -i1 -r64 -n1g -g1g -f /mnt/ff
KB reclen write rewrite read reread
1048576 64 5068 3324 640266 641609
-------------------------------------------------------------------------------
drivers/mmc/card/block.c | 43 +++++++++++++++++++
drivers/mmc/card/queue.c | 102 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/mmc/card/queue.h | 6 +++
3 files changed, 149 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 0c959c9..790abe2 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -59,6 +59,9 @@ MODULE_ALIAS("mmc:block"); #define INAND_CMD38_ARG_SECTRIM1 0x81 #define INAND_CMD38_ARG_SECTRIM2 0x88
+#define MMC_MIN_QUEUE_BOUNCESZ 4096
+#define MMC_MAX_QUEUE_BOUNCESZ 4194304
+
static DEFINE_MUTEX(block_mutex);
/*
@@ -108,6 +111,7 @@ struct mmc_blk_data {
unsigned int part_curr;
struct device_attribute force_ro;
struct device_attribute power_ro_lock;
+ struct device_attribute bouncesz;
int area_type;
};
@@ -1633,6 +1637,7 @@ static void mmc_blk_remove_req(struct mmc_blk_data *md)
del_gendisk(md->disk);
}
+ device_remove_file(disk_to_dev(md->disk), &md->bouncesz);
/* Then flush out any already in there */
mmc_cleanup_queue(&md->queue);
mmc_blk_put(md);
@@ -1739,6 +1744,33 @@ static const struct mmc_fixup blk_fixups[] =
END_FIXUP
};
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+static ssize_t mmc_bouncesz_show(struct device *dev,
+ struct device_attribute *attr, char *buf) {
+ return sprintf(buf, "%u\n", mmc_queue_bouncesz); }
+
+static ssize_t mmc_bouncesz_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ unsigned int bouncesz;
+ struct mmc_blk_data *md;
+
+ if ((sscanf(buf, "%d", &bouncesz) != 1) ||
+ (bouncesz < MMC_MIN_QUEUE_BOUNCESZ) ||
+ (bouncesz > MMC_MAX_QUEUE_BOUNCESZ) ||
+ (bouncesz % 512 != 0))
+ return -EINVAL;
+
+ md = mmc_blk_get(dev_to_disk(dev));
+ mmc_reinit_bounce_queue(&md->queue, md->queue.card, bouncesz);
+ mmc_blk_put(md);
+ return mmc_queue_bouncesz;
+}
+#endif
+
static int mmc_blk_probe(struct mmc_card *card) {
struct mmc_blk_data *md, *part_md;
@@ -1771,6 +1803,17 @@ static int mmc_blk_probe(struct mmc_card *card)
mmc_set_drvdata(card, md);
mmc_fixup_device(card, blk_fixups);
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+ md->bouncesz.show = mmc_bouncesz_show;
+ md->bouncesz.store = mmc_bouncesz_store;
+ sysfs_attr_init(&md->bouncesz.attr);
+ md->bouncesz.attr.name = "bouncesz";
+ md->bouncesz.attr.mode = S_IRUGO | S_IWUSR;
+ err = device_create_file(disk_to_dev(md->disk), &md->bouncesz);
+ if (err)
+ goto out;
+#endif
+
if (mmc_add_disk(md))
goto out;
diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c index dcad59c..c563e33 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -21,7 +21,9 @@
#include "queue.h"
#define MMC_QUEUE_BOUNCESZ 65536
-
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+unsigned mmc_queue_bouncesz = MMC_QUEUE_BOUNCESZ; #endif
#define MMC_QUEUE_SUSPENDED (1 << 0)
/*
@@ -185,7 +187,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
if (host->max_segs == 1) {
unsigned int bouncesz;
- bouncesz = MMC_QUEUE_BOUNCESZ;
+ bouncesz = mmc_queue_bouncesz;
if (bouncesz > host->max_req_size)
bouncesz = host->max_req_size;
@@ -329,6 +331,102 @@ void mmc_cleanup_queue(struct mmc_queue *mq)
EXPORT_SYMBOL(mmc_cleanup_queue);
/**
+ * mmc_reinit_bounce_queue - re-initialise a bounce buffer.
+ * @mq: mmc queue
+ * @card: mmc card to attach this queue
+ * @bouncesz: the bounce size that need re-initializing
+ *
+ * Initialise a MMC card request queue.
+ */
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+int mmc_reinit_bounce_queue(struct mmc_queue *mq, struct mmc_card *card,
+ unsigned int bouncesz)
+{
+ struct mmc_host *host = card->host;
+ struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
+ struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
+ int ret;
+ struct scatterlist *curr_bounce_sg, *prev_bounce_sg;
+ char *curr_bounce_buf, *prev_bounce_buf;
+
+ mmc_claim_host(card->host);
+
+ bouncesz = min(bouncesz, host->max_req_size);
+ bouncesz = min(bouncesz, host->max_seg_size);
+ bouncesz = min(bouncesz, host->max_blk_count * 512);
+
+ /* store current using addr of bounce_buf and bounce_sg */
+ curr_bounce_sg = mqrq_cur->bounce_sg;
+ prev_bounce_sg = mqrq_prev->bounce_sg;
+ curr_bounce_buf = mqrq_cur->bounce_buf;
+ prev_bounce_buf = mqrq_prev->bounce_buf;
+
+ if (host->max_segs != 1)
+ goto restore_queue;
+
+ /* realloc bounce queue use given bounce size */
+ mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+ if (!mqrq_cur->bounce_buf) {
+ printk(KERN_WARNING "%s: unable to "
+ "allocate bounce cur buffer\n",
+ mmc_card_name(card));
+ ret = -ENOMEM;
+ goto restore_queue;
+ }
+
+ mqrq_prev->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
+ if (!mqrq_prev->bounce_buf) {
+ printk(KERN_WARNING "%s: unable to "
+ "allocate bounce prev buffer\n",
+ mmc_card_name(card));
+ kfree(mqrq_cur->bounce_buf);
+ mqrq_cur->bounce_buf = NULL;
+ ret = -ENOMEM;
+ goto restore_queue;
+ }
+
+ mqrq_cur->bounce_sg =
+ mmc_alloc_sg(bouncesz / 512, &ret);
+ if (ret)
+ goto cleanup_queue;
+
+ mqrq_prev->bounce_sg =
+ mmc_alloc_sg(bouncesz / 512, &ret);
+ if (ret)
+ goto cleanup_queue;
+
+ blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
+ blk_queue_max_segments(mq->queue, bouncesz / 512);
+ blk_queue_max_segment_size(mq->queue, bouncesz);
+ mmc_queue_bouncesz = bouncesz;
+
+ kfree(curr_bounce_sg);
+ kfree(prev_bounce_sg);
+ kfree(curr_bounce_buf);
+ kfree(prev_bounce_buf);
+
+ mmc_release_host(card->host);
+ return 0;
+
+cleanup_queue:
+ /* cleanup bounce queue first */
+ kfree(mqrq_cur->sg);
+ kfree(mqrq_cur->bounce_buf);
+ kfree(mqrq_prev->sg);
+ kfree(mqrq_prev->bounce_buf);
+
+restore_queue:
+ mqrq_cur->bounce_buf = curr_bounce_buf;
+ mqrq_prev->bounce_buf = prev_bounce_buf;
+ mqrq_cur->bounce_sg = curr_bounce_sg;
+ mqrq_prev->bounce_sg = prev_bounce_sg;
+
+ mmc_release_host(card->host);
+ return ret;
+}
+#endif
+
+/**
* mmc_queue_suspend - suspend a MMC request queue
* @mq: MMC queue to suspend
*
diff --git a/drivers/mmc/card/queue.h b/drivers/mmc/card/queue.h
index d2a1eb4..c1dee6d 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -46,4 +46,10 @@ extern unsigned int mmc_queue_map_sg(struct mmc_queue *,
extern void mmc_queue_bounce_pre(struct mmc_queue_req *);
extern void mmc_queue_bounce_post(struct mmc_queue_req *);
+#ifdef CONFIG_MMC_BLOCK_BOUNCE
+extern int mmc_reinit_bounce_queue(struct mmc_queue *, struct mmc_card *,
+ unsigned int);
+extern unsigned mmc_queue_bouncesz;
+#endif
+
#endif
--
1.6.4
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