On 3/14/19 4:05 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> During phases 2-5, xfs_scrub should estimate the level of
> parallelization possible on the data device to determine the number of
> threads spawned to scrub filesystem metadata, not just blindly using the
> number of CPUs. This avoids flooding non-rotational storage with random
> reads, which totally destroys performance and makes scrub runtimes
> higher.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
seems like when I first looked at this I had a concern but now I don't
remember, and today it seems fine? :)
Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> ---
> scrub/phase1.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
>
> diff --git a/scrub/phase1.c b/scrub/phase1.c
> index 2113014b..6b472147 100644
> --- a/scrub/phase1.c
> +++ b/scrub/phase1.c
> @@ -109,13 +109,6 @@ _("Must be root to run scrub."));
> return false;
> }
>
> - ctx->nr_io_threads = nproc;
> - if (verbose) {
> - fprintf(stdout, _("%s: using %d threads to scrub.\n"),
> - ctx->mntpoint, scrub_nproc(ctx));
> - fflush(stdout);
> - }
> -
> if (!platform_test_xfs_fd(ctx->mnt_fd)) {
> str_info(ctx, ctx->mntpoint,
> _("Does not appear to be an XFS filesystem!"));
> @@ -193,6 +186,13 @@ _("Unable to find realtime device path."));
> return false;
> }
>
> + ctx->nr_io_threads = disk_heads(ctx->datadev);
> + if (verbose) {
> + fprintf(stdout, _("%s: using %d threads to scrub.\n"),
> + ctx->mntpoint, scrub_nproc(ctx));
> + fflush(stdout);
> + }
> +
> if (ctx->fsinfo.fs_log) {
> ctx->logdev = disk_open(ctx->fsinfo.fs_log);
> if (error) {
>
