On Tue, Oct 12, 2021 at 04:33:28PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> Compute the actual maximum btree height when deciding if per-AG block
> reservation is critically low. This only affects the sanity check
> condition, since we /generally/ will trigger on the 10% threshold.
> This is a long-winded way of saying that we're removing one more
> usage of XFS_BTREE_MAXLEVELS.
And replacing it with a branchy dynamic calculation that has a
static, unchanging result. :(
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_ag_resv.c | 18 +++++++++++++++++-
> 1 file changed, 17 insertions(+), 1 deletion(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
> index 2aa2b3484c28..d34d4614f175 100644
> --- a/fs/xfs/libxfs/xfs_ag_resv.c
> +++ b/fs/xfs/libxfs/xfs_ag_resv.c
> @@ -60,6 +60,20 @@
> * to use the reservation system should update ask/used in xfs_ag_resv_init.
> */
>
> +/* Compute maximum possible height for per-AG btree types for this fs. */
> +static unsigned int
> +xfs_ag_btree_maxlevels(
> + struct xfs_mount *mp)
> +{
> + unsigned int ret = mp->m_ag_maxlevels;
> +
> + ret = max(ret, mp->m_bm_maxlevels[XFS_DATA_FORK]);
> + ret = max(ret, mp->m_bm_maxlevels[XFS_ATTR_FORK]);
> + ret = max(ret, M_IGEO(mp)->inobt_maxlevels);
> + ret = max(ret, mp->m_rmap_maxlevels);
> + return max(ret, mp->m_refc_maxlevels);
> +}
Hmmmm. perhaps mp->m_ag_maxlevels should be renamed to
mp->m_agbno_maxlevels and we pre-calculate mp->m_ag_maxlevels from
the above function and just use the variable in the
xfs_ag_resv_critical() check?
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
