Re: [PATCH 08/18] io-controller: idle for sometime on sync queuebefore expiring it

From: Vivek Goyal
Date: Tue Jun 09 2009 - 13:52:38 EST


On Tue, Jun 09, 2009 at 03:56:38PM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> ...
> > +ssize_t elv_fairness_store(struct request_queue *q, const char *name,
> > + size_t count)
> > +{
> > + struct elv_fq_data *efqd;
> > + unsigned int data;
> > + unsigned long flags;
> > +
> > + char *p = (char *)name;
> > +
> > + data = simple_strtoul(p, &p, 10);
> > +
> > + if (data < 0)
> > + data = 0;
> > + else if (data > INT_MAX)
> > + data = INT_MAX;
>
> Hi Vivek,
>
> data might overflow on 64 bit systems. In addition, since "fairness" is nothing
> more than a switch, just let it be.
>
> Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
> ---

Hi Gui,

How about following patch? Currently this should apply at the end of the
patch series. If it looks good, I will merge the changes in higher level
patches.

Thanks
Vivek

o Previously common layer elevator parameters were appearing as request
queue parameters in sysfs. But actually these are io scheduler parameters
in hiearchical mode. Fix it.

o Use macros to define multiple sysfs C functions doing the same thing. Code
borrowed from CFQ. Helps reduce the number of lines of by 140.

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
block/as-iosched.c | 5
block/blk-sysfs.c | 39 -------
block/cfq-iosched.c | 5
block/deadline-iosched.c | 5
block/elevator-fq.c | 245 +++++++++++------------------------------------
block/elevator-fq.h | 26 ++--
block/noop-iosched.c | 10 +
7 files changed, 97 insertions(+), 238 deletions(-)

Index: linux18/block/elevator-fq.h
===================================================================
--- linux18.orig/block/elevator-fq.h 2009-06-09 10:34:59.000000000 -0400
+++ linux18/block/elevator-fq.h 2009-06-09 13:35:03.000000000 -0400
@@ -27,6 +27,9 @@ struct io_queue;

#ifdef CONFIG_ELV_FAIR_QUEUING

+#define ELV_ATTR(name) \
+ __ATTR(name, S_IRUGO|S_IWUSR, elv_##name##_show, elv_##name##_store)
+
/**
* struct bfq_service_tree - per ioprio_class service tree.
* @active: tree for active entities (i.e., those backlogged).
@@ -364,7 +367,7 @@ struct elv_fq_data {
* throughput and focus more on providing fairness for sync
* queues.
*/
- int fairness;
+ unsigned int fairness;
int only_root_group;
};

@@ -650,23 +653,22 @@ static inline struct io_queue *elv_looku

#endif /* GROUP_IOSCHED */

-/* Functions used by blksysfs.c */
-extern ssize_t elv_slice_idle_show(struct request_queue *q, char *name);
-extern ssize_t elv_slice_idle_store(struct request_queue *q, const char *name,
+extern ssize_t elv_slice_idle_show(struct elevator_queue *e, char *name);
+extern ssize_t elv_slice_idle_store(struct elevator_queue *e, const char *name,
size_t count);
-extern ssize_t elv_slice_sync_show(struct request_queue *q, char *name);
-extern ssize_t elv_slice_sync_store(struct request_queue *q, const char *name,
+extern ssize_t elv_slice_sync_show(struct elevator_queue *e, char *name);
+extern ssize_t elv_slice_sync_store(struct elevator_queue *e, const char *name,
size_t count);

-extern ssize_t elv_async_slice_idle_show(struct request_queue *q, char *name);
-extern ssize_t elv_async_slice_idle_store(struct request_queue *q,
+extern ssize_t elv_async_slice_idle_show(struct elevator_queue *e, char *name);
+extern ssize_t elv_async_slice_idle_store(struct elevator_queue *e,
const char *name, size_t count);

-extern ssize_t elv_slice_async_show(struct request_queue *q, char *name);
-extern ssize_t elv_slice_async_store(struct request_queue *q, const char *name,
+extern ssize_t elv_slice_async_show(struct elevator_queue *e, char *name);
+extern ssize_t elv_slice_async_store(struct elevator_queue *e, const char *name,
size_t count);
-extern ssize_t elv_fairness_show(struct request_queue *q, char *name);
-extern ssize_t elv_fairness_store(struct request_queue *q, const char *name,
+extern ssize_t elv_fairness_show(struct elevator_queue *e, char *name);
+extern ssize_t elv_fairness_store(struct elevator_queue *e, const char *name,
size_t count);

/* Functions used by elevator.c */
Index: linux18/block/elevator-fq.c
===================================================================
--- linux18.orig/block/elevator-fq.c 2009-06-09 10:34:59.000000000 -0400
+++ linux18/block/elevator-fq.c 2009-06-09 13:39:48.000000000 -0400
@@ -2618,201 +2618,72 @@ static inline int is_root_group_ioq(stru
return (ioq->entity.sched_data == &efqd->root_group->sched_data);
}

-/* Functions to show and store fairness value through sysfs */
-ssize_t elv_fairness_show(struct request_queue *q, char *name)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- data = efqd->fairness;
- spin_unlock_irqrestore(q->queue_lock, flags);
- return sprintf(name, "%d\n", data);
-}
-
-ssize_t elv_fairness_store(struct request_queue *q, const char *name,
- size_t count)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- char *p = (char *)name;
-
- data = simple_strtoul(p, &p, 10);
-
- if (data < 0)
- data = 0;
- else if (data > INT_MAX)
- data = INT_MAX;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- efqd->fairness = data;
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return count;
-}
-
-/* Functions to show and store elv_idle_slice value through sysfs */
-ssize_t elv_slice_idle_show(struct request_queue *q, char *name)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- data = jiffies_to_msecs(efqd->elv_slice_idle);
- spin_unlock_irqrestore(q->queue_lock, flags);
- return sprintf(name, "%d\n", data);
-}
-
-ssize_t elv_slice_idle_store(struct request_queue *q, const char *name,
- size_t count)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- char *p = (char *)name;
-
- data = simple_strtoul(p, &p, 10);
-
- if (data < 0)
- data = 0;
- else if (data > INT_MAX)
- data = INT_MAX;
-
- data = msecs_to_jiffies(data);
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- efqd->elv_slice_idle = data;
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return count;
-}
-
-/* Functions to show and store elv_idle_slice value through sysfs */
-ssize_t elv_async_slice_idle_show(struct request_queue *q, char *name)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- data = jiffies_to_msecs(efqd->elv_async_slice_idle);
- spin_unlock_irqrestore(q->queue_lock, flags);
- return sprintf(name, "%d\n", data);
-}
-
-ssize_t elv_async_slice_idle_store(struct request_queue *q, const char *name,
- size_t count)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- char *p = (char *)name;
-
- data = simple_strtoul(p, &p, 10);
-
- if (data < 0)
- data = 0;
- else if (data > INT_MAX)
- data = INT_MAX;
-
- data = msecs_to_jiffies(data);
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- efqd->elv_async_slice_idle = data;
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return count;
-}
-
-/* Functions to show and store elv_slice_sync value through sysfs */
-ssize_t elv_slice_sync_show(struct request_queue *q, char *name)
+/*
+ * sysfs parts below -->
+ */
+static ssize_t
+elv_var_show(unsigned int var, char *page)
{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- data = efqd->elv_slice[1];
- spin_unlock_irqrestore(q->queue_lock, flags);
- return sprintf(name, "%d\n", data);
+ return sprintf(page, "%d\n", var);
}

-ssize_t elv_slice_sync_store(struct request_queue *q, const char *name,
- size_t count)
+static ssize_t
+elv_var_store(unsigned int *var, const char *page, size_t count)
{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- char *p = (char *)name;
-
- data = simple_strtoul(p, &p, 10);
-
- if (data < 0)
- data = 0;
- /* 100ms is the limit for now*/
- else if (data > 100)
- data = 100;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- efqd->elv_slice[1] = data;
- spin_unlock_irqrestore(q->queue_lock, flags);
+ char *p = (char *) page;

+ *var = simple_strtoul(p, &p, 10);
return count;
}

-/* Functions to show and store elv_slice_async value through sysfs */
-ssize_t elv_slice_async_show(struct request_queue *q, char *name)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- data = efqd->elv_slice[0];
- spin_unlock_irqrestore(q->queue_lock, flags);
- return sprintf(name, "%d\n", data);
-}
-
-ssize_t elv_slice_async_store(struct request_queue *q, const char *name,
- size_t count)
-{
- struct elv_fq_data *efqd;
- unsigned int data;
- unsigned long flags;
-
- char *p = (char *)name;
-
- data = simple_strtoul(p, &p, 10);
-
- if (data < 0)
- data = 0;
- /* 100ms is the limit for now*/
- else if (data > 100)
- data = 100;
-
- spin_lock_irqsave(q->queue_lock, flags);
- efqd = &q->elevator->efqd;
- efqd->elv_slice[0] = data;
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return count;
-}
+#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
+ssize_t __FUNC(struct elevator_queue *e, char *page) \
+{ \
+ struct elv_fq_data *efqd = &e->efqd; \
+ unsigned int __data = __VAR; \
+ if (__CONV) \
+ __data = jiffies_to_msecs(__data); \
+ return elv_var_show(__data, (page)); \
+}
+SHOW_FUNCTION(elv_fairness_show, efqd->fairness, 0);
+EXPORT_SYMBOL(elv_fairness_show);
+SHOW_FUNCTION(elv_slice_idle_show, efqd->elv_slice_idle, 1);
+EXPORT_SYMBOL(elv_slice_idle_show);
+SHOW_FUNCTION(elv_async_slice_idle_show, efqd->elv_async_slice_idle, 1);
+EXPORT_SYMBOL(elv_async_slice_idle_show);
+SHOW_FUNCTION(elv_slice_sync_show, efqd->elv_slice[1], 1);
+EXPORT_SYMBOL(elv_slice_sync_show);
+SHOW_FUNCTION(elv_slice_async_show, efqd->elv_slice[0], 1);
+EXPORT_SYMBOL(elv_slice_async_show);
+#undef SHOW_FUNCTION
+
+#define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV) \
+ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) \
+{ \
+ struct elv_fq_data *efqd = &e->efqd; \
+ unsigned int __data; \
+ int ret = elv_var_store(&__data, (page), count); \
+ if (__data < (MIN)) \
+ __data = (MIN); \
+ else if (__data > (MAX)) \
+ __data = (MAX); \
+ if (__CONV) \
+ *(__PTR) = msecs_to_jiffies(__data); \
+ else \
+ *(__PTR) = __data; \
+ return ret; \
+}
+STORE_FUNCTION(elv_fairness_store, &efqd->fairness, 0, 1, 0);
+EXPORT_SYMBOL(elv_fairness_store);
+STORE_FUNCTION(elv_slice_idle_store, &efqd->elv_slice_idle, 0, UINT_MAX, 1);
+EXPORT_SYMBOL(elv_slice_idle_store);
+STORE_FUNCTION(elv_async_slice_idle_store, &efqd->elv_async_slice_idle, 0, UINT_MAX, 1);
+EXPORT_SYMBOL(elv_async_slice_idle_store);
+STORE_FUNCTION(elv_slice_sync_store, &efqd->elv_slice[1], 1, UINT_MAX, 1);
+EXPORT_SYMBOL(elv_slice_sync_store);
+STORE_FUNCTION(elv_slice_async_store, &efqd->elv_slice[0], 1, UINT_MAX, 1);
+EXPORT_SYMBOL(elv_slice_async_store);
+#undef STORE_FUNCTION

void elv_schedule_dispatch(struct request_queue *q)
{
Index: linux18/block/blk-sysfs.c
===================================================================
--- linux18.orig/block/blk-sysfs.c 2009-06-09 10:34:59.000000000 -0400
+++ linux18/block/blk-sysfs.c 2009-06-09 13:24:42.000000000 -0400
@@ -307,38 +307,6 @@ static struct queue_sysfs_entry queue_io
.store = queue_iostats_store,
};

-#ifdef CONFIG_ELV_FAIR_QUEUING
-static struct queue_sysfs_entry queue_slice_idle_entry = {
- .attr = {.name = "slice_idle", .mode = S_IRUGO | S_IWUSR },
- .show = elv_slice_idle_show,
- .store = elv_slice_idle_store,
-};
-
-static struct queue_sysfs_entry queue_async_slice_idle_entry = {
- .attr = {.name = "async_slice_idle", .mode = S_IRUGO | S_IWUSR },
- .show = elv_async_slice_idle_show,
- .store = elv_async_slice_idle_store,
-};
-
-static struct queue_sysfs_entry queue_slice_sync_entry = {
- .attr = {.name = "slice_sync", .mode = S_IRUGO | S_IWUSR },
- .show = elv_slice_sync_show,
- .store = elv_slice_sync_store,
-};
-
-static struct queue_sysfs_entry queue_slice_async_entry = {
- .attr = {.name = "slice_async", .mode = S_IRUGO | S_IWUSR },
- .show = elv_slice_async_show,
- .store = elv_slice_async_store,
-};
-
-static struct queue_sysfs_entry queue_fairness_entry = {
- .attr = {.name = "fairness", .mode = S_IRUGO | S_IWUSR },
- .show = elv_fairness_show,
- .store = elv_fairness_store,
-};
-#endif
-
static struct attribute *default_attrs[] = {
&queue_requests_entry.attr,
#ifdef CONFIG_GROUP_IOSCHED
@@ -353,13 +321,6 @@ static struct attribute *default_attrs[]
&queue_nomerges_entry.attr,
&queue_rq_affinity_entry.attr,
&queue_iostats_entry.attr,
-#ifdef CONFIG_ELV_FAIR_QUEUING
- &queue_slice_idle_entry.attr,
- &queue_async_slice_idle_entry.attr,
- &queue_slice_sync_entry.attr,
- &queue_slice_async_entry.attr,
- &queue_fairness_entry.attr,
-#endif
NULL,
};

Index: linux18/block/cfq-iosched.c
===================================================================
--- linux18.orig/block/cfq-iosched.c 2009-06-09 10:34:55.000000000 -0400
+++ linux18/block/cfq-iosched.c 2009-06-09 13:25:42.000000000 -0400
@@ -2095,6 +2095,11 @@ static struct elv_fs_entry cfq_attrs[] =
CFQ_ATTR(back_seek_max),
CFQ_ATTR(back_seek_penalty),
CFQ_ATTR(slice_async_rq),
+ ELV_ATTR(fairness),
+ ELV_ATTR(slice_idle),
+ ELV_ATTR(async_slice_idle),
+ ELV_ATTR(slice_sync),
+ ELV_ATTR(slice_async),
__ATTR_NULL
};

Index: linux18/block/as-iosched.c
===================================================================
--- linux18.orig/block/as-iosched.c 2009-06-09 10:34:58.000000000 -0400
+++ linux18/block/as-iosched.c 2009-06-09 13:27:38.000000000 -0400
@@ -1766,6 +1766,11 @@ static struct elv_fs_entry as_attrs[] =
AS_ATTR(antic_expire),
AS_ATTR(read_batch_expire),
AS_ATTR(write_batch_expire),
+#ifdef CONFIG_IOSCHED_AS_HIER
+ ELV_ATTR(fairness),
+ ELV_ATTR(slice_idle),
+ ELV_ATTR(slice_sync),
+#endif
__ATTR_NULL
};

Index: linux18/block/deadline-iosched.c
===================================================================
--- linux18.orig/block/deadline-iosched.c 2009-06-09 10:34:55.000000000 -0400
+++ linux18/block/deadline-iosched.c 2009-06-09 13:28:51.000000000 -0400
@@ -460,6 +460,11 @@ static struct elv_fs_entry deadline_attr
DD_ATTR(writes_starved),
DD_ATTR(front_merges),
DD_ATTR(fifo_batch),
+#ifdef CONFIG_IOSCHED_DEADLINE_HIER
+ ELV_ATTR(fairness),
+ ELV_ATTR(slice_idle),
+ ELV_ATTR(slice_sync),
+#endif
__ATTR_NULL
};

Index: linux18/block/noop-iosched.c
===================================================================
--- linux18.orig/block/noop-iosched.c 2009-06-09 10:34:52.000000000 -0400
+++ linux18/block/noop-iosched.c 2009-06-09 13:31:48.000000000 -0400
@@ -82,6 +82,15 @@ static void noop_free_noop_queue(struct
kfree(nq);
}

+#ifdef CONFIG_IOSCHED_NOOP_HIER
+static struct elv_fs_entry noop_attrs[] = {
+ ELV_ATTR(fairness),
+ ELV_ATTR(slice_idle),
+ ELV_ATTR(slice_sync),
+ __ATTR_NULL
+};
+#endif
+
static struct elevator_type elevator_noop = {
.ops = {
.elevator_merge_req_fn = noop_merged_requests,
@@ -94,6 +103,7 @@ static struct elevator_type elevator_noo
},
#ifdef CONFIG_IOSCHED_NOOP_HIER
.elevator_features = ELV_IOSCHED_NEED_FQ | ELV_IOSCHED_SINGLE_IOQ,
+ .elevator_attrs = noop_attrs,
#endif
.elevator_name = "noop",
.elevator_owner = THIS_MODULE,
--
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