From: Shaohua Li <shaohua.li@intel.com>
To: linux-kernel@vger.kernel.org
Cc: axboe@kernel.dk, vgoyal@redhat.com, jmoyer@redhat.com,
Shaohua Li <shaohua.li@intel.com>
Subject: [RFC 3/3]block: fiops read/write request scale
Date: Wed, 04 Jan 2012 14:53:40 +0800 [thread overview]
Message-ID: <20120104065454.297272010@sli10-conroe.sh.intel.com> (raw)
In-Reply-To: 20120104065337.230911609@sli10-conroe.sh.intel.com
[-- Attachment #1: fiops-rw-scale.patch --]
[-- Type: text/plain, Size: 3614 bytes --]
read/write speed of Flash based storage usually is different. Add a scale
to differenate read and write. Also add a tunable, so user can assign
different scale for read and write. This can also be used to bias read
or write in the system
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
---
block/fiops-iosched.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 68 insertions(+), 1 deletion(-)
Index: linux/block/fiops-iosched.c
===================================================================
--- linux.orig/block/fiops-iosched.c 2012-01-04 14:01:26.000000000 +0800
+++ linux/block/fiops-iosched.c 2012-01-04 14:05:48.000000000 +0800
@@ -15,6 +15,9 @@
#define VIOS_SCALE_SHIFT 10
#define VIOS_SCALE (1 << VIOS_SCALE_SHIFT)
+#define VIOS_READ_SCALE (1)
+#define VIOS_WRITE_SCALE (1)
+
struct fiops_rb_root {
struct rb_root rb;
struct rb_node *left;
@@ -32,6 +35,9 @@ struct fiops_data {
unsigned int busy_queues;
struct work_struct unplug_work;
+
+ unsigned int read_scale;
+ unsigned int write_scale;
};
struct fiops_ioc {
@@ -268,7 +274,10 @@ static void fiops_remove_request(struct
static u64 fiops_scaled_vios(struct fiops_data *fiopsd,
struct fiops_ioc *ioc, struct request *rq)
{
- return VIOS_SCALE;
+ if (rq_data_dir(rq) == READ)
+ return VIOS_SCALE;
+ else
+ return VIOS_SCALE * fiopsd->write_scale / fiopsd->read_scale;
}
/* return vios dispatched */
@@ -540,6 +549,9 @@ static void *fiops_init_queue(struct req
INIT_WORK(&fiopsd->unplug_work, fiops_kick_queue);
+ fiopsd->read_scale = VIOS_READ_SCALE;
+ fiopsd->write_scale = VIOS_WRITE_SCALE;
+
return fiopsd;
}
@@ -610,6 +622,60 @@ static struct ioc_builder ioc_builder =
.cic_exit = fiops_exit_cic,
};
+/*
+ * sysfs parts below -->
+ */
+static ssize_t
+fiops_var_show(unsigned int var, char *page)
+{
+ return sprintf(page, "%d\n", var);
+}
+
+static ssize_t
+fiops_var_store(unsigned int *var, const char *page, size_t count)
+{
+ char *p = (char *) page;
+
+ *var = simple_strtoul(p, &p, 10);
+ return count;
+}
+
+#define SHOW_FUNCTION(__FUNC, __VAR) \
+static ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct fiops_data *fiopsd = e->elevator_data; \
+ return fiops_var_show(__VAR, (page)); \
+}
+SHOW_FUNCTION(fiops_read_scale_show, fiopsd->read_scale);
+SHOW_FUNCTION(fiops_write_scale_show, fiopsd->write_scale);
+#undef SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX) \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct fiops_data *fiopsd = e->elevator_data; \
+ unsigned int __data; \
+ int ret = fiops_var_store(&__data, (page), count); \
+ if (__data < (MIN)) \
+ __data = (MIN); \
+ else if (__data > (MAX)) \
+ __data = (MAX); \
+ *(__PTR) = __data; \
+ return ret; \
+}
+STORE_FUNCTION(fiops_read_scale_store, &fiopsd->read_scale, 1, 100);
+STORE_FUNCTION(fiops_write_scale_store, &fiopsd->write_scale, 1, 100);
+#undef STORE_FUNCTION
+
+#define FIOPS_ATTR(name) \
+ __ATTR(name, S_IRUGO|S_IWUSR, fiops_##name##_show, fiops_##name##_store)
+
+static struct elv_fs_entry fiops_attrs[] = {
+ FIOPS_ATTR(read_scale),
+ FIOPS_ATTR(write_scale),
+ __ATTR_NULL
+};
+
static struct elevator_type iosched_fiops = {
.ops = {
.elevator_merge_fn = fiops_merge,
@@ -626,6 +692,7 @@ static struct elevator_type iosched_fiop
.elevator_exit_fn = fiops_exit_queue,
.trim = queue_data_free_io_context,
},
+ .elevator_attrs = fiops_attrs,
.elevator_name = "fiops",
.elevator_owner = THIS_MODULE,
};
next prev parent reply other threads:[~2012-01-04 6:40 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 6:53 [RFC 0/3]block: An IOPS based ioscheduler Shaohua Li
2012-01-04 6:53 ` [RFC 1/3]block: seperate CFQ io context management code Shaohua Li
2012-01-04 8:19 ` Namhyung Kim
2012-01-04 6:53 ` [RFC 2/3]block: FIOPS ioscheduler core Shaohua Li
2012-01-06 6:05 ` Namjae Jeon
2012-01-07 1:06 ` Zhu Yanhai
2012-01-04 6:53 ` Shaohua Li [this message]
2012-01-04 7:19 ` [RFC 0/3]block: An IOPS based ioscheduler Dave Chinner
2012-01-05 6:50 ` Shaohua Li
2012-01-06 5:12 ` Shaohua Li
2012-01-06 9:10 ` Namhyung Kim
2012-01-06 14:37 ` Jan Kara
2012-01-09 1:26 ` Shaohua Li
2012-01-15 22:32 ` Vivek Goyal
2012-01-08 22:16 ` Dave Chinner
2012-01-09 1:09 ` Shaohua Li
2012-01-15 22:45 ` Vivek Goyal
2012-01-16 4:36 ` Shaohua Li
2012-01-16 7:11 ` Vivek Goyal
2012-01-16 7:55 ` Shaohua Li
2012-01-16 8:29 ` Vivek Goyal
2012-01-17 1:06 ` Shaohua Li
2012-01-17 9:02 ` Vivek Goyal
2012-01-18 1:20 ` Shaohua Li
2012-01-18 13:04 ` Vivek Goyal
2012-01-19 1:21 ` Shaohua Li
2012-01-15 22:28 ` Vivek Goyal
2012-01-06 9:41 ` Zhu Yanhai
2012-01-15 22:24 ` Vivek Goyal
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