On Thu, Oct 08, 2009 at 01:59:07PM +0800, KAMEZAWA Hiroyuki wrote:
> On Thu, 8 Oct 2009 12:01:36 +0800
> Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote:
>
> > On Thu, Oct 08, 2009 at 10:40:37AM +0800, KAMEZAWA Hiroyuki wrote:
> > > Thank you for clarification.
> > > Then, hmm, %iotwait (which 'top' shows) didn't work as desgined and we need
> > > to update throttle_vm_writeout() and some in vmscan.c. Thanks for input.
> >
> > Thanks, you also reminds me to do io_schedule() in the nfs writeback
> > wait queue :)
> >
> good side effect ;)
Done, hehe.
> > > BTW, I'm glad if I can know "how many threads/ios are throttoled now" per bdi.
> >
> > Good suggestion. How about this patch?
> >
>
> Seems attractive.
> Hmm..
> ==
> struct dirty_throttle_task {
> + pid_t owner_pid;
> ==
> and show it ? (too verbose ?
I even thought of adding the task pointer - it won't go away anyway :)
Thanks,
Fengguang
>
> Regards,
> -Kame
>
> > CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> > Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
> > ---
> > fs/fs-writeback.c | 1 +
> > include/linux/backing-dev.h | 2 ++
> > mm/backing-dev.c | 33 +++++++++++++++++++++++++++++++++
> > 3 files changed, 36 insertions(+)
> >
> > --- linux.orig/include/linux/backing-dev.h 2009-10-08 11:46:28.000000000 +0800
> > +++ linux/include/linux/backing-dev.h 2009-10-08 11:47:39.000000000 +0800
> > @@ -101,6 +101,7 @@ struct backing_dev_info {
> > #ifdef CONFIG_DEBUG_FS
> > struct dentry *debug_dir;
> > struct dentry *debug_stats;
> > + struct dentry *debug_throttle;
> > #endif
> > };
> >
> > @@ -116,6 +117,7 @@ struct backing_dev_info {
> > #define DIRTY_THROTTLE_PAGES_STOP (1 << 22)
> >
> > struct dirty_throttle_task {
> > + unsigned long start_time;
> > long nr_pages;
> > struct list_head list;
> > struct completion complete;
> > --- linux.orig/mm/backing-dev.c 2009-10-08 11:47:37.000000000 +0800
> > +++ linux/mm/backing-dev.c 2009-10-08 11:59:06.000000000 +0800
> > @@ -115,6 +115,23 @@ static int bdi_debug_stats_show(struct s
> > return 0;
> > }
> >
> > +static int bdi_debug_throttle_show(struct seq_file *m, void *v)
> > +{
> > + struct backing_dev_info *bdi = m->private;
> > + struct dirty_throttle_task *tt;
> > + unsigned long flags;
> > +
> > + spin_lock_irqsave(&bdi->throttle_lock, flags);
> > + list_for_each_entry(tt, &bdi->throttle_list, list) {
> > + seq_printf(m, "goal=%lukb\twaited=%lums\n",
> > + tt->nr_pages << (PAGE_SHIFT - 10),
> > + (jiffies - tt->start_time) * 1000 / HZ);
> > + }
> > + spin_unlock_irqrestore(&bdi->throttle_lock, flags);
> > +
> > + return 0;
> > +}
> > +
> > static int bdi_debug_stats_open(struct inode *inode, struct file *file)
> > {
> > return single_open(file, bdi_debug_stats_show, inode->i_private);
> > @@ -127,15 +144,31 @@ static const struct file_operations bdi_
> > .release = single_release,
> > };
> >
> > +static int bdi_debug_throttle_open(struct inode *inode, struct file *file)
> > +{
> > + return single_open(file, bdi_debug_throttle_show, inode->i_private);
> > +}
> > +
> > +static const struct file_operations bdi_debug_throttle_fops = {
> > + .open = bdi_debug_throttle_open,
> > + .read = seq_read,
> > + .llseek = seq_lseek,
> > + .release = single_release,
> > +};
> > +
> > static void bdi_debug_register(struct backing_dev_info *bdi, const char *name)
> > {
> > bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root);
> > bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir,
> > bdi, &bdi_debug_stats_fops);
> > + bdi->debug_throttle = debugfs_create_file("throttle_list", 0444,
> > + bdi->debug_dir, bdi,
> > + &bdi_debug_throttle_fops);
> > }
> >
> > static void bdi_debug_unregister(struct backing_dev_info *bdi)
> > {
> > + debugfs_remove(bdi->debug_throttle);
> > debugfs_remove(bdi->debug_stats);
> > debugfs_remove(bdi->debug_dir);
> > }
> > --- linux.orig/fs/fs-writeback.c 2009-10-08 11:44:27.000000000 +0800
> > +++ linux/fs/fs-writeback.c 2009-10-08 11:47:39.000000000 +0800
> > @@ -284,6 +284,7 @@ static void bdi_calc_write_bandwidth(str
> > void bdi_writeback_wait(struct backing_dev_info *bdi, long nr_pages)
> > {
> > struct dirty_throttle_task tt = {
> > + .start_time = jiffies,
> > .nr_pages = nr_pages,
> > .complete = COMPLETION_INITIALIZER_ONSTACK(tt.complete),
> > };
> >
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
