Re: [PATCH 1/9] writeback: make writeback_control.nr_to_write straight

Wu Fengguang
2011-07-01T12:03:45Z

> Just one minor nit:
>
> > @@ -570,17 +622,25 @@ static int writeback_sb_inodes(struct su
> > iput(inode);
> > cond_resched();
> > spin_lock(&wb->list_lock);
> > - if (wbc->nr_to_write <= 0)
> > - return 1;
> > + /*
> > + * bail out to wb_writeback() often enough to check
> > + * background threshold and other termination conditions.
> > + */
> > + if (wrote) {
> > + if (jiffies - start_time > HZ / 10UL)
> > + break;
> I guess this comparison should use time_before() macro - or maybe even
> time_is_before_jiffies().

Fair enough. Changed to:

if (time_is_before_jiffies(start_time + HZ / 10UL))

> > + if (work->nr_pages <= 0)
> > + break;
> > + }
> > }
> > - /* b_io is empty */
> > - return 1;
> > + return wrote;
> > }
> >
> > -static void __writeback_inodes_wb(struct bdi_writeback *wb,
> > - struct writeback_control *wbc)
> > +static long __writeback_inodes_wb(struct bdi_writeback *wb,
> > + struct wb_writeback_work *work)
> > {
> > - int ret = 0;
> > + unsigned long start_time = jiffies;
> > + long wrote = 0;
> >
> > while (!list_empty(&wb->b_io)) {
> > struct inode *inode = wb_inode(wb->b_io.prev);
> > @@ -590,33 +650,37 @@ static void __writeback_inodes_wb(struct
> > requeue_io(inode, wb);
> > continue;
> > }
> > - ret = writeback_sb_inodes(sb, wb, wbc, false);
> > + wrote += writeback_sb_inodes(sb, wb, work);
> > drop_super(sb);
> >
> > - if (ret)
> > - break;
> > + /* refer to the same tests at the end of writeback_sb_inodes */
> > + if (wrote) {
> > + if (jiffies - start_time > HZ / 10UL)
> > + break;
> And the same here.

Changed together. Thanks for the review!

Fengguang