Hi Christoph:
On Tue, Jul 19, 2011 at 9:46 AM, Curt Wohlgemuth <curtw@xxxxxxxxxx> wrote:
> On Fri, Jul 15, 2011 at 4:44 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
>> On Fri, Jul 15, 2011 at 04:41:38PM -0700, Curt Wohlgemuth wrote:
>>> $ cat /proc/writeback/stats
>>> call: balance_dirty_pages 2253
>>> call: background_writeout 45
>>> call: try_to_free_pages 0
>>> call: sync 14
>>> call: kupdate 228
>>> call: shrink_page_list 0
>>> call: fdatawrite 6755
>>> call: laptop_periodic 0
>>> call: free_more_memory 0
>>> page: balance_dirty_pages 455830
>>> page: background_writeout 391568
>>> page: try_to_free_pages 0
>>> page: sync 133
>>> page: kupdate 1158779
>>> page: shrink_page_list 0
>>> page: fdatawrite 777320
>>> page: laptop_periodic 0
>>> page: free_more_memory 0
>>> periodic writeback 241
>>> single inode wait 0
>>> writeback_wb wait 7
>>> metadata pages cleaned 19473
>>
>> A fair amount of the page stats should be provided by Wu and Jan's
>> recent patches, shouldn't they? I don't think the calls stats
>> are such a good idea. We can triviall get these stats by using
>> perf - just place a probe at the function and then count it using
>> perf record.
>
> Well, sure, you can get all these stats via perf/ftrace/whatever, if
> you want to place the probes in the right spot, and count them up. I
> personally think that having total counts (that are monotonically
> increasing) always available is pretty convenient, including the call
> counts. But I agree, the page counts and the "metadata pages cleaned"
> are the most valuable.
>
> I looked through Jan's and Fengguang's recent patches for such stats,
> but didn't see anything -- though I could easily have missed them.
>
>> But if would be good to get the remaining page stats in, as they
>> seems pretty useful.
>
> I'll resend another patch without the call counts, see what people think.
Here's a version of the writeback stats patch without call counts, and
is hence a bit simpler. I retained the 'why' field in a
wb_writeback_work because it's simple :-) .
This patch is based on Fengguang's tree at
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback.git , not
on the kernel.org tree.
Thanks,
Curt
From 8e8eec4aa8c0a5b8ea3363be23da406581586cfa Mon Sep 17 00:00:00 2001
From: Curt Wohlgemuth <curtw@xxxxxxxxxx>
Date: Fri, 15 Jul 2011 15:50:13 -0700
Subject: [PATCH 1/2] writeback: Add writeback stats
This creates a global file,
/proc/writeback/stats
which displays global data about the writeback subsystem:
$ cat /proc/writeback/stats
call: balance_dirty_pages 2253
call: background_writeout 45
call: try_to_free_pages 0
call: sync 14
call: kupdate 228
call: shrink_page_list 0
call: fdatawrite 6755
call: laptop_periodic 0
call: free_more_memory 0
page: balance_dirty_pages 455830
page: background_writeout 391568
page: try_to_free_pages 0
page: sync 133
page: kupdate 1158779
page: shrink_page_list 0
page: fdatawrite 777320
page: laptop_periodic 0
page: free_more_memory 0
periodic writeback 241
single inode wait 0
writeback_wb wait 7
metadata pages cleaned 19473
Per-BDI stats are available as well, in
/sys/block/<device>/bdi/writeback_stats
Signed-off-by: Curt Wohlgemuth <curtw@xxxxxxxxxx>
---
fs/buffer.c | 2 +-
fs/fs-writeback.c | 37 ++++++++++--
fs/proc/Makefile | 1 +
fs/proc/internal.h | 1 +
fs/proc/proc_writeback.c | 145 +++++++++++++++++++++++++++++++++++++++++++
fs/proc/root.c | 1 +
fs/sync.c | 2 +-
include/linux/backing-dev.h | 8 ++-
include/linux/writeback.h | 50 +++++++++++++++-
mm/backing-dev.c | 41 ++++++++++++
mm/filemap.c | 7 ++
mm/page-writeback.c | 7 ++-
mm/vmscan.c | 10 +++-
13 files changed, 301 insertions(+), 11 deletions(-)
create mode 100644 fs/proc/proc_writeback.c
diff --git a/fs/buffer.c b/fs/buffer.c
index 1a80b04..cfca642 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -285,7 +285,7 @@ static void free_more_memory(void)
struct zone *zone;
int nid;
- wakeup_flusher_threads(1024);
+ wakeup_flusher_threads(1024, WB_STAT_FREE_MORE_MEM);
yield();
for_each_online_node(nid) {
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 0f015a0..472ec44 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -39,6 +39,7 @@ struct wb_writeback_work {
unsigned int for_kupdate:1;
unsigned int range_cyclic:1;
unsigned int for_background:1;
+ int why;
struct list_head list; /* pending work list */
struct completion *done; /* set if the caller waits */
@@ -113,7 +114,7 @@ static void bdi_queue_work(struct backing_dev_info *bdi,
static void
__bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
- bool range_cyclic)
+ bool range_cyclic, enum wb_stats stat)
{
struct wb_writeback_work *work;
@@ -133,6 +134,7 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
work->sync_mode = WB_SYNC_NONE;
work->nr_pages = nr_pages;
work->range_cyclic = range_cyclic;
+ work->why = stat;
bdi_queue_work(bdi, work);
}
@@ -148,9 +150,10 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
* completion. Caller need not hold sb s_umount semaphore.
*
*/
-void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages)
+void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
+ enum wb_stats stat)
{
- __bdi_start_writeback(bdi, nr_pages, true);
+ __bdi_start_writeback(bdi, nr_pages, true, stat);
}
/**
@@ -374,6 +377,8 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
/*
* It's a data-integrity sync. We must wait.
*/
+ bdi_writeback_stat_inc(inode->i_mapping->backing_dev_info,
+ WB_STAT_SINGLE_INODE_WAIT);
inode_wait_for_writeback(inode);
}
@@ -501,6 +506,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
{
while (!list_empty(&wb->b_io)) {
long pages_skipped;
+ int req, wrote;
struct inode *inode = wb_inode(wb->b_io.prev);
if (inode->i_sb != sb) {
@@ -546,7 +552,9 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
__iget(inode);
pages_skipped = wbc->pages_skipped;
+ req = wbc->nr_to_write;
writeback_single_inode(inode, wbc);
+ wrote = req - wbc->nr_to_write;
if (wbc->pages_skipped != pages_skipped) {
/*
* writeback is not making progress due to locked
@@ -554,6 +562,9 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
*/
redirty_tail(inode);
}
+ if (inode->i_ino == 0)
+ bdi_writeback_stat_add(wb->bdi,
+ WB_STAT_METADATA_PAGES_CLEANED, wrote);
spin_unlock(&inode->i_lock);
spin_unlock(&inode_wb_list_lock);
iput(inode);
@@ -688,6 +699,8 @@ static long wb_writeback(struct bdi_writeback *wb,
else
write_chunk = LONG_MAX;
+ bdi_writeback_stat_inc(wb->bdi, work->why);
+
wbc.wb_start = jiffies; /* livelock avoidance */
for (;;) {
/*
@@ -724,6 +737,12 @@ static long wb_writeback(struct bdi_writeback *wb,
writeback_inodes_wb(wb, &wbc);
trace_wbc_writeback_written(&wbc, wb->bdi);
+ if (work->why < WB_STAT_PG_COUNT_BASE) {
+ bdi_writeback_stat_add(wb->bdi,
+ work->why + WB_STAT_PG_COUNT_BASE,
+ write_chunk - wbc.nr_to_write);
+ }
+
work->nr_pages -= write_chunk - wbc.nr_to_write;
wrote += write_chunk - wbc.nr_to_write;
@@ -752,6 +771,9 @@ static long wb_writeback(struct bdi_writeback *wb,
inode = wb_inode(wb->b_more_io.prev);
trace_wbc_writeback_wait(&wbc, wb->bdi);
spin_lock(&inode->i_lock);
+ bdi_writeback_stat_inc(
+ inode->i_mapping->backing_dev_info,
+ WB_STAT_WRITEBACK_WB_WAIT);
inode_wait_for_writeback(inode);
spin_unlock(&inode->i_lock);
}
@@ -799,6 +821,7 @@ static long wb_check_background_flush(struct bdi_writeback *wb)
.sync_mode = WB_SYNC_NONE,
.for_background = 1,
.range_cyclic = 1,
+ .why = WB_STAT_BG_WRITEOUT,
};
return wb_writeback(wb, &work);
@@ -832,6 +855,7 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
.sync_mode = WB_SYNC_NONE,
.for_kupdate = 1,
.range_cyclic = 1,
+ .why = WB_STAT_KUPDATE,
};
return wb_writeback(wb, &work);
@@ -910,6 +934,7 @@ int bdi_writeback_thread(void *data)
*/
del_timer(&wb->wakeup_timer);
+ bdi_writeback_stat_inc(bdi, WB_STAT_PERIODIC);
pages_written = wb_do_writeback(wb, 0);
trace_writeback_pages_written(pages_written);
@@ -950,7 +975,7 @@ int bdi_writeback_thread(void *data)
* Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back
* the whole world.
*/
-void wakeup_flusher_threads(long nr_pages)
+void wakeup_flusher_threads(long nr_pages, enum wb_stats stat)
{
struct backing_dev_info *bdi;
@@ -963,7 +988,7 @@ void wakeup_flusher_threads(long nr_pages)
list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
if (!bdi_has_dirty_io(bdi))
continue;
- __bdi_start_writeback(bdi, nr_pages, false);
+ __bdi_start_writeback(bdi, nr_pages, false, stat);
}
rcu_read_unlock();
}
@@ -1192,6 +1217,7 @@ void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr)
.sync_mode = WB_SYNC_NONE,
.done = &done,
.nr_pages = nr,
+ .why = WB_STAT_SYNC, /* XXX: Not always correct */
};
WARN_ON(!rwsem_is_locked(&sb->s_umount));
@@ -1270,6 +1296,7 @@ void sync_inodes_sb(struct super_block *sb)
.nr_pages = LONG_MAX,
.range_cyclic = 0,
.done = &done,
+ .why = WB_STAT_SYNC,
};
WARN_ON(!rwsem_is_locked(&sb->s_umount));
diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index c1c7293..edac008 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -21,6 +21,7 @@ proc-y += uptime.o
proc-y += version.o
proc-y += softirqs.o
proc-y += namespaces.o
+proc-y += proc_writeback.o
proc-$(CONFIG_PROC_SYSCTL) += proc_sysctl.o
proc-$(CONFIG_NET) += proc_net.o
proc-$(CONFIG_PROC_KCORE) += kcore.o
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 7838e5c..43797ec 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -23,6 +23,7 @@ extern int proc_net_init(void);
static inline int proc_net_init(void) { return 0; }
#endif
+extern void proc_writeback_init(void);
struct vmalloc_info {
unsigned long used;
unsigned long largest_chunk;
diff --git a/fs/proc/proc_writeback.c b/fs/proc/proc_writeback.c
new file mode 100644
index 0000000..4614697
--- /dev/null
+++ b/fs/proc/proc_writeback.c
@@ -0,0 +1,145 @@
+/*
+ * linux/fs/proc/proc_writeback.c
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/mm.h>
+#include <linux/percpu.h>
+#include <linux/writeback.h>
+#include <linux/uaccess.h>
+#include <linux/backing-dev.h>
+#include "internal.h"
+
+struct writeback_stats *writeback_sys_stats;
+
+enum writeback_op {
+ WB_STATS_OP,
+};
+
+static const char *wb_stats_labels[WB_STAT_MAX] = {
+ [WB_STAT_BALANCE_DIRTY] = "call: balance_dirty_pages",
+ [WB_STAT_BG_WRITEOUT] = "call: background_writeout",
+ [WB_STAT_TRY_TO_FREE_PAGES] = "call: try_to_free_pages",
+ [WB_STAT_SYNC] = "call: sync",
+ [WB_STAT_KUPDATE] = "call: kupdate",
+ [WB_STAT_SHRINK_PAGE_LIST] = "call: shrink_page_list",
+ [WB_STAT_FDATAWRITE] = "call: fdatawrite",
+ [WB_STAT_LAPTOP_TIMER] = "call: laptop_periodic",
+ [WB_STAT_FREE_MORE_MEM] = "call: free_more_memory",
+
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_BALANCE_DIRTY] =
+ "page: balance_dirty_pages",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_BG_WRITEOUT] =
+ "page: background_writeout",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_TRY_TO_FREE_PAGES] =
+ "page: try_to_free_pages",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_SYNC] =
+ "page: sync",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_KUPDATE] =
+ "page: kupdate",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_SHRINK_PAGE_LIST] =
+ "page: shrink_page_list",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_FDATAWRITE] =
+ "page: fdatawrite",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_LAPTOP_TIMER] =
+ "page: laptop_periodic",
+ [WB_STAT_PG_COUNT_BASE + WB_STAT_FREE_MORE_MEM] =
+ "page: free_more_memory",
+
+ [WB_STAT_PERIODIC] = "periodic writeback",
+ [WB_STAT_SINGLE_INODE_WAIT] = "single inode wait",
+ [WB_STAT_WRITEBACK_WB_WAIT] = "writeback_wb wait",
+ [WB_STAT_METADATA_PAGES_CLEANED] = "metadata pages cleaned",
+};
+
+static void writeback_stats_collect(struct writeback_stats *src,
+ struct writeback_stats *target)
+{
+ int cpu;
+ for_each_online_cpu(cpu) {
+ int stat;
+ struct writeback_stats *stats = per_cpu_ptr(src, cpu);
+ for (stat = 0; stat < WB_STAT_MAX; stat++)
+ target->stats[stat] += stats->stats[stat];
+ }
+}
+
+static size_t writeback_stats_to_str(struct writeback_stats *stats,
+ char *buf, size_t len)
+{
+ int bufsize = len - 1;
+ int i, printed = 0;
+ for (i = 0; i < WB_STAT_MAX; i++) {
+ const char *label = wb_stats_labels[i];
+ if (label == NULL)
+ continue;
+ printed += snprintf(buf + printed, bufsize - printed,
+ "%-32s %10llu\n", label, stats->stats[i]);
+ if (printed >= bufsize) {
+ buf[len - 1] = '\n';
+ return len;
+ }
+ }
+
+ buf[printed - 1] = '\n';
+ return printed;
+}
+
+size_t writeback_stats_print(struct writeback_stats *stats,
+ char *buf, size_t len)
+{
+ struct writeback_stats total;
+ memset(&total, 0, sizeof(total));
+ writeback_stats_collect(stats, &total);
+ return writeback_stats_to_str(&total, buf, len);
+}
+
+
+static int writeback_seq_show(struct seq_file *m, void *data)
+{
+ char *buf;
+ size_t size;
+ switch ((enum writeback_op)m->private) {
+ case WB_STATS_OP:
+ size = seq_get_buf(m, &buf);
+ if (size == 0)
+ return 0;
+ size = writeback_stats_print(writeback_sys_stats, buf, size);
+ seq_commit(m, size);
+ break;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static int writeback_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, writeback_seq_show, PDE(inode)->data);
+}
+
+static const struct file_operations writeback_ops = {
+ .open = writeback_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+
+void __init proc_writeback_init(void)
+{
+ struct proc_dir_entry *base_dir;
+ base_dir = proc_mkdir("writeback", NULL);
+ if (base_dir == NULL) {
+ printk(KERN_ERR "Creating /proc/writeback/ failed");
+ return;
+ }
+
+ writeback_sys_stats = alloc_percpu(struct writeback_stats);
+
+ proc_create_data("stats", S_IRUGO|S_IWUSR, base_dir,
+ &writeback_ops, (void *)WB_STATS_OP);
+}
diff --git a/fs/proc/root.c b/fs/proc/root.c
index d6c3b41..a44e166 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -125,6 +125,7 @@ void __init proc_root_init(void)
#endif
proc_mkdir("bus", NULL);
proc_sys_init();
+ proc_writeback_init();
}
static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
diff --git a/fs/sync.c b/fs/sync.c
index c38ec16..f4c7085 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -98,7 +98,7 @@ static void sync_filesystems(int wait)
*/
SYSCALL_DEFINE0(sync)
{
- wakeup_flusher_threads(0);
+ wakeup_flusher_threads(0, WB_STAT_SYNC);
sync_filesystems(0);
sync_filesystems(1);
if (unlikely(laptop_mode))
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 96f4094..648b06f 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -70,6 +70,7 @@ struct backing_dev_info {
char *name;
struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS];
+ struct writeback_stats *wb_stat;
struct prop_local_percpu completions;
int dirty_exceeded;
@@ -100,7 +101,8 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
void bdi_unregister(struct backing_dev_info *bdi);
int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
-void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages);
+void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
+ enum wb_stats stat);
void bdi_start_background_writeback(struct backing_dev_info *bdi);
int bdi_writeback_thread(void *data);
int bdi_has_dirty_io(struct backing_dev_info *bdi);
@@ -181,6 +183,10 @@ static inline s64 bdi_stat_sum(struct backing_dev_info *bdi,
return sum;
}
+void bdi_writeback_stat_inc(struct backing_dev_info *bdi, enum wb_stats stat);
+void bdi_writeback_stat_add(struct backing_dev_info *bdi, enum wb_stats stat,
+ unsigned long value);
+
extern void bdi_writeout_inc(struct backing_dev_info *bdi);
/*
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 17e7ccc..6fe2247 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -20,6 +20,54 @@ enum writeback_sync_modes {
};
/*
+ * why this writeback was initiated
+ */
+enum wb_stats {
+ WB_STAT_BALANCE_DIRTY,
+ WB_STAT_BG_WRITEOUT,
+ WB_STAT_TRY_TO_FREE_PAGES,
+ WB_STAT_SYNC,
+ WB_STAT_KUPDATE,
+ WB_STAT_SHRINK_PAGE_LIST,
+ WB_STAT_FDATAWRITE,
+ WB_STAT_LAPTOP_TIMER,
+ WB_STAT_FREE_MORE_MEM,
+
+ /*
+ * For event that you want both call count and pages associated
+ * with the call, add them above.
+ *
+ * [0 : WB_STAT_PAGES_COUNT_BASE - 1] stores number of calls
+ * pages count will be stored starting from WB_STAT_PAGES_COUNT_BASE
+ */
+ WB_STAT_PG_COUNT_BASE,
+
+ WB_STAT_PERIODIC = WB_STAT_PG_COUNT_BASE * 2,
+ WB_STAT_SINGLE_INODE_WAIT,
+ WB_STAT_WRITEBACK_WB_WAIT,
+ WB_STAT_METADATA_PAGES_CLEANED,
+ WB_STAT_MAX,
+};
+
+struct writeback_stats {
+ u64 stats[WB_STAT_MAX];
+};
+
+extern struct writeback_stats *writeback_sys_stats;
+
+static inline struct writeback_stats *writeback_stats_alloc(void)
+{
+ return alloc_percpu(struct writeback_stats);
+}
+
+static inline void writeback_stats_free(struct writeback_stats *stats)
+{
+ free_percpu(stats);
+}
+
+size_t writeback_stats_print(struct writeback_stats *, char *buf, size_t);
+
+/*
* A control structure which tells the writeback code what to do. These are
* always on the stack, and hence need no locking. They are always initialised
* in a manner such that unspecified fields are set to zero.
@@ -65,7 +113,7 @@ void sync_inodes_sb(struct super_block *);
void writeback_inodes_wb(struct bdi_writeback *wb,
struct writeback_control *wbc);
long wb_do_writeback(struct bdi_writeback *wb, int force_wait);
-void wakeup_flusher_threads(long nr_pages);
+void wakeup_flusher_threads(long nr_pages, enum wb_stats stat);
/* writeback.h requires fs.h; it, too, is not included from here. */
static inline void wait_on_inode(struct inode *inode)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f032e6e..e69e492 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -138,6 +138,13 @@ static inline void bdi_debug_unregister(struct backing_dev_info *bdi)
}
#endif
+static ssize_t writeback_stats_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct backing_dev_info *bdi = dev_get_drvdata(dev);
+ return writeback_stats_print(bdi->wb_stat, buf, PAGE_SIZE);
+}
+
static ssize_t read_ahead_kb_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
@@ -210,6 +217,7 @@ static struct device_attribute bdi_dev_attrs[] = {
__ATTR_RW(read_ahead_kb),
__ATTR_RW(min_ratio),
__ATTR_RW(max_ratio),
+ __ATTR_RO(writeback_stats),
__ATTR_NULL,
};
@@ -652,11 +660,18 @@ int bdi_init(struct backing_dev_info *bdi)
goto err;
}
+ bdi->wb_stat = writeback_stats_alloc();
+ if (bdi->wb_stat == NULL) {
+ err = -ENOMEM;
+ goto err;
+ }
+
bdi->dirty_exceeded = 0;
err = prop_local_init_percpu(&bdi->completions);
if (err) {
err:
+ writeback_stats_free(bdi->wb_stat);
while (i--)
percpu_counter_destroy(&bdi->bdi_stat[i]);
}
@@ -688,6 +703,8 @@ void bdi_destroy(struct backing_dev_info *bdi)
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
percpu_counter_destroy(&bdi->bdi_stat[i]);
+ writeback_stats_free(bdi->wb_stat);
+
prop_local_destroy_percpu(&bdi->completions);
}
EXPORT_SYMBOL(bdi_destroy);
@@ -830,3 +847,27 @@ out:
return ret;
}
EXPORT_SYMBOL(wait_iff_congested);
+
+void bdi_writeback_stat_add(struct backing_dev_info *bdi, enum wb_stats stat,
+ unsigned long value)
+{
+ if (bdi) {
+ struct writeback_stats *stats = bdi->wb_stat;
+
+ BUG_ON(stat >= WB_STAT_MAX);
+ preempt_disable();
+ stats = per_cpu_ptr(stats, smp_processor_id());
+ stats->stats[stat] += value;
+ if (likely(writeback_sys_stats)) {
+ stats = per_cpu_ptr(writeback_sys_stats,
+ smp_processor_id());
+ stats->stats[stat] += value;
+ }
+ preempt_enable();
+ }
+}
+
+void bdi_writeback_stat_inc(struct backing_dev_info *bdi, enum wb_stats stat)
+{
+ bdi_writeback_stat_add(bdi, stat, 1);
+}
diff --git a/mm/filemap.c b/mm/filemap.c
index a8251a8..6ac8ce2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -218,7 +218,14 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
if (!mapping_cap_writeback_dirty(mapping))
return 0;
+ bdi_writeback_stat_inc(mapping->backing_dev_info,
+ WB_STAT_FDATAWRITE);
+
ret = do_writepages(mapping, &wbc);
+
+ bdi_writeback_stat_add(mapping->backing_dev_info,
+ WB_STAT_FDATAWRITE + WB_STAT_PG_COUNT_BASE,
+ LONG_MAX - wbc.nr_to_write);
return ret;
}
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 31f6988..5333968 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -559,7 +559,11 @@ static void balance_dirty_pages(struct address_space *mapping,
*/
trace_wbc_balance_dirty_start(&wbc, bdi);
if (bdi_nr_reclaimable > bdi_thresh) {
+ bdi_writeback_stat_inc(bdi, WB_STAT_BALANCE_DIRTY);
writeback_inodes_wb(&bdi->wb, &wbc);
+ bdi_writeback_stat_add(bdi,
+ WB_STAT_BALANCE_DIRTY + WB_STAT_PG_COUNT_BASE,
+ write_chunk - wbc.nr_to_write);
pages_written += write_chunk - wbc.nr_to_write;
trace_wbc_balance_dirty_written(&wbc, bdi);
if (pages_written >= write_chunk)
@@ -703,7 +707,8 @@ void laptop_mode_timer_fn(unsigned long data)
* threshold
*/
if (bdi_has_dirty_io(&q->backing_dev_info))
- bdi_start_writeback(&q->backing_dev_info, nr_pages);
+ bdi_start_writeback(&q->backing_dev_info, nr_pages,
+ WB_STAT_LAPTOP_TIMER);
}
/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5ed24b9..04cd8b1 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -447,6 +447,8 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
};
SetPageReclaim(page);
+ bdi_writeback_stat_inc(mapping->backing_dev_info,
+ WB_STAT_SHRINK_PAGE_LIST);
res = mapping->a_ops->writepage(page, &wbc);
if (res < 0)
handle_write_error(mapping, page, res);
@@ -454,6 +456,11 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
ClearPageReclaim(page);
return PAGE_ACTIVATE;
}
+ if (res >= 0) {
+ bdi_writeback_stat_inc(mapping->backing_dev_info,
+ WB_STAT_SHRINK_PAGE_LIST +
+ WB_STAT_PG_COUNT_BASE);
+ }
/*
* Wait on writeback if requested to. This happens when
@@ -2131,7 +2138,8 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
*/
writeback_threshold = sc->nr_to_reclaim + sc->nr_to_reclaim / 2;
if (total_scanned > writeback_threshold) {
- wakeup_flusher_threads(laptop_mode ? 0 : total_scanned);
+ wakeup_flusher_threads(laptop_mode ? 0 : total_scanned,
+ WB_STAT_TRY_TO_FREE_PAGES);
sc->may_writepage = 1;
}
--
1.7.3.1
