Hi Chris,
What's your opinion about this patch?
I changed to adjust bounce size at run time through
echo /sys/block/mmcblk0/bouncesz.
Thanks.
-----Original Message-----
From: Liu Qiang-B32616
Sent: Thursday, November 24, 2011 11:06 AM
To: cjb@xxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx
Cc: Li Yang-R58472; Liu Qiang-B32616
Subject: [PATCH 1/2] SD/MMC: add an interface to re-initialize bounce buffer
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>
---
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/queue.c | 102 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/mmc/card/queue.h | 6 +++
2 files changed, 106 insertions(+), 2 deletions(-)
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..468356f 100644
--- a/drivers/mmc/card/queue.h
+++ b/drivers/mmc/card/queue.h
@@ -37,6 +37,8 @@ struct mmc_queue {
extern int mmc_init_queue(struct mmc_queue *, struct mmc_card *, spinlock_t *,
const char *);
+extern int mmc_reinit_bounce_queue(struct mmc_queue *, struct mmc_card *,
+ unsigned int);
extern void mmc_cleanup_queue(struct mmc_queue *);
extern void mmc_queue_suspend(struct mmc_queue *);
extern void mmc_queue_resume(struct mmc_queue *);
@@ -46,4 +48,8 @@ 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 unsigned mmc_queue_bouncesz;
+#endif
+
#endif
--
1.6.4
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