On Mon, Feb 04, 2019 at 12:35:00PM -0600, Eric Sandeen wrote:
> On 12/19/18 1:30 PM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> >
> > Since we use the same read-verify pool object to dispatch file data read
> > requests for both the data device and the realtime device, we should
> > create enough IO threads to handle the estimated parallelization of both
> > devices, not just the data device.
> >
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> So if rtdev is on SSD and datadev is on a rotational device, won't we
> possibly still Launch All Threads at the rotational device for this
> case, and won't that still hurt? I'm not sure it works to lump these
> together, does it? (I also don't know if it can be done another way...)
Hmm. I think we /could/ have separate readverify pools for data and rt
devices. Let me look into that...
--D
> -Eric
>
>
> > ---
> > scrub/phase6.c | 20 ++++++++++++++++++--
> > 1 file changed, 18 insertions(+), 2 deletions(-)
> >
> >
> > diff --git a/scrub/phase6.c b/scrub/phase6.c
> > index ead48d77..cbda9b53 100644
> > --- a/scrub/phase6.c
> > +++ b/scrub/phase6.c
> > @@ -435,6 +435,22 @@ xfs_check_rmap(
> > return true;
> > }
> >
> > +/*
> > + * Estimate the amount of parallelization possible for scanning file data on
> > + * the data and realtime devices.
> > + */
> > +static unsigned int
> > +phase6_threads(
> > + struct scrub_ctx *ctx)
> > +{
> > + unsigned int nr = disk_heads(ctx->datadev);
> > +
> > + if (ctx->rtdev)
> > + nr += disk_heads(ctx->rtdev);
> > +
> > + return nr > nproc ? nproc : nr;
> > +}
> > +
> > /*
> > * Read verify all the file data blocks in a filesystem. Since XFS doesn't
> > * do data checksums, we trust that the underlying storage will pass back
> > @@ -469,7 +485,7 @@ xfs_scan_blocks(
> > }
> >
> > ve.readverify = read_verify_pool_init(ctx, ctx->geo.blocksize,
> > - xfs_check_rmap_ioerr, disk_heads(ctx->datadev));
> > + xfs_check_rmap_ioerr, phase6_threads(ctx));
> > if (!ve.readverify) {
> > moveon = false;
> > str_info(ctx, ctx->mntpoint,
> > @@ -525,7 +541,7 @@ xfs_estimate_verify_work(
> > return moveon;
> >
> > *items = ((d_blocks - d_bfree) + (r_blocks - r_bfree)) << ctx->blocklog;
> > - *nr_threads = disk_heads(ctx->datadev);
> > + *nr_threads = phase6_threads(ctx);
> > *rshift = 20;
> > return moveon;
> > }
> >
