On Thu, Jan 23, 2020 at 05:10:19PM -0800, Darrick J. Wong wrote:
> On Thu, Jan 23, 2020 at 04:32:17PM +0800, Murphy Zhou wrote:
> > Hi,
> >
> > Deleting the files left by generic/175 costs too much time when testing
> > on NFSv4.2 exporting xfs with rmapbt=1.
> >
> > "./check -nfs generic/175 generic/176" should reproduce it.
> >
> > My test bed is a 16c8G vm.
>
> What kind of storage?
>
> > NFSv4.2 rmapbt=1 24h+
>
> <URK> Wow. I wonder what about NFS makes us so slow now? Synchronous
> transactions on the inactivation? (speculates wildly at the end of the
> workday)
>
> I'll have a look in the morning. It might take me a while to remember
> how to set up NFS42 :)
It may just be the default on a recent enough distro.
Though I'd be a little surprised if this behavior is specific to the
protocol version.
nfsd_unlink() is basically just vfs_unlink() followed by
commit_metadata().
--b.
>
> --D
>
> > NFSv4.2 rmapbt=0 1h-2h
> > xfs rmapbt=1 10m+
> >
> > At first I thought it hung, turns out it was just slow when deleting
> > 2 massive reflined files.
> >
> > It's reproducible using latest Linus tree, and Darrick's deferred-inactivation
> > branch. Run latest for-next branch xfsprogs.
> >
> > I'm not sure it's something wrong, just sharing with you guys. I don't
> > remember I have identified this as a regression. It should be there for
> > a long time.
> >
> > Sending to xfs and nfs because it looks like all related. :)
> >
> > This almost gets lost in my list. Not much information recorded, some
> > trace-cmd outputs for your info. It's easy to reproduce. If it's
> > interesting to you and need any info, feel free to ask.
> >
> > Thanks,
> >
> >
> > 7) 0.279 us | xfs_btree_get_block [xfs]();
> > 7) 0.303 us | xfs_btree_rec_offset [xfs]();
> > 7) 0.301 us | xfs_rmapbt_init_high_key_from_rec [xfs]();
> > 7) 0.356 us | xfs_rmapbt_diff_two_keys [xfs]();
> > 7) 0.305 us | xfs_rmapbt_init_key_from_rec [xfs]();
> > 7) 0.306 us | xfs_rmapbt_diff_two_keys [xfs]();
> > 7) | xfs_rmap_query_range_helper [xfs]() {
> > 7) 0.279 us | xfs_rmap_btrec_to_irec [xfs]();
> > 7) | xfs_rmap_lookup_le_range_helper [xfs]() {
> > 1) 0.786 us | _raw_spin_lock_irqsave();
> > 7) | /* xfs_rmap_lookup_le_range_candidate: dev 8:34 agno 2 agbno 6416 len 256 owner 67160161 offset 99284480 flags 0x0 */
> > 7) 0.506 us | }
> > 7) 1.680 us | }
