Hi, > -----Original Message----- > From: Dave Chinner [mailto:david@xxxxxxxxxxxxx] > Sent: Saturday, March 01, 2014 8:27 AM > To: Chao Yu > Cc: ???; linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: [f2fs-dev] [PATCH] f2fs: fix dirty page accounting when redirty > > On Fri, Feb 28, 2014 at 10:12:05AM +0800, Chao Yu wrote: > > We should de-account dirty counters for page when redirty in ->writepage(). > > > > Wu Fengguang described in 'commit 971767caf632190f77a40b4011c19948232eed75': > > "writeback: fix dirtied pages accounting on redirty > > De-account the accumulative dirty counters on page redirty. > > > > Page redirties (very common in ext4) will introduce mismatch between > > counters (a) and (b) > > > > a) NR_DIRTIED, BDI_DIRTIED, tsk->nr_dirtied > > b) NR_WRITTEN, BDI_WRITTEN > > > > This will introduce systematic errors in balanced_rate and result in > > dirty page position errors (ie. the dirty pages are no longer balanced > > around the global/bdi setpoints)." > > > > Signed-off-by: Chao Yu <chao2.yu@xxxxxxxxxxx> > > --- > > fs/f2fs/checkpoint.c | 1 + > > fs/f2fs/data.c | 1 + > > fs/f2fs/node.c | 1 + > > 3 files changed, 3 insertions(+) > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > index c8516ee..f069249 100644 > > --- a/fs/f2fs/checkpoint.c > > +++ b/fs/f2fs/checkpoint.c > > @@ -178,6 +178,7 @@ no_write: > > redirty_out: > > dec_page_count(sbi, F2FS_DIRTY_META); > > wbc->pages_skipped++; > > + account_page_redirty(page); > > set_page_dirty(page); > > return AOP_WRITEPAGE_ACTIVATE; > > redirty_page_for_writepage()? set_page_dirty() in a_ops of f2fs not only call __set_page_dirty_nobuffers(), but also set some private data of page and print trace info. So it seems we could not easily replace with redirty_page_for_writepage(). Thanks. > > Cheers, > > Dave. > -- > Dave Chinner > david@xxxxxxxxxxxxx -- 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
