diff options
| author | Steven Whitehouse <swhiteho@redhat.com> | 2012-10-31 10:37:10 +0000 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2012-11-07 13:33:17 +0000 |
| commit | 9dbe9610b9df4efe0946299804ed46bb8f91dec2 (patch) | |
| tree | 8d54797420ed9d0aef1c6bdd8f3b8dd5e9938d0a /fs/gfs2/rgrp.c | |
| parent | c9aecf73717f55e41ac11682a50bef8594547025 (diff) | |
GFS2: Add Orlov allocator
Just like ext3, this works on the root directory and any directory
with the +T flag set. Also, just like ext3, any subdirectory created
in one of the just mentioned cases will be allocated to a random
resource group (GFS2 equivalent of a block group).
If you are creating a set of directories, each of which will contain a
job running on a different node, then by setting +T on the parent
directory before creating the subdirectories, each will land up in a
different resource group, and thus resource group contention between
nodes will be kept to a minimum.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/rgrp.c')
| -rw-r--r-- | fs/gfs2/rgrp.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index bdf3e644baa..99a619788c6 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -16,6 +16,7 @@ #include <linux/prefetch.h> #include <linux/blkdev.h> #include <linux/rbtree.h> +#include <linux/random.h> #include "gfs2.h" #include "incore.h" @@ -1763,6 +1764,15 @@ static bool gfs2_rgrp_used_recently(const struct gfs2_blkreserv *rs, return tdiff > (msecs * 1000 * 1000); } +static u32 gfs2_orlov_skip(const struct gfs2_inode *ip) +{ + const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + u32 skip; + + get_random_bytes(&skip, sizeof(skip)); + return skip % sdp->sd_rgrps; +} + static bool gfs2_select_rgrp(struct gfs2_rgrpd **pos, const struct gfs2_rgrpd *begin) { struct gfs2_rgrpd *rgd = *pos; @@ -1784,7 +1794,7 @@ static bool gfs2_select_rgrp(struct gfs2_rgrpd **pos, const struct gfs2_rgrpd *b * Returns: errno */ -int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested) +int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested, u32 aflags) { struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); struct gfs2_rgrpd *begin = NULL; @@ -1792,6 +1802,7 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested) int error = 0, rg_locked, flags = 0; u64 last_unlinked = NO_BLOCK; int loops = 0; + u32 skip = 0; if (sdp->sd_args.ar_rgrplvb) flags |= GL_SKIP; @@ -1805,6 +1816,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested) } else { rs->rs_rbm.rgd = begin = gfs2_blk2rgrpd(sdp, ip->i_goal, 1); } + if (S_ISDIR(ip->i_inode.i_mode) && (aflags & GFS2_AF_ORLOV)) + skip = gfs2_orlov_skip(ip); if (rs->rs_rbm.rgd == NULL) return -EBADSLT; @@ -1813,6 +1826,8 @@ int gfs2_inplace_reserve(struct gfs2_inode *ip, u32 requested) if (!gfs2_glock_is_locked_by_me(rs->rs_rbm.rgd->rd_gl)) { rg_locked = 0; + if (skip && skip--) + goto next_rgrp; if (!gfs2_rs_active(rs) && (loops < 2) && gfs2_rgrp_used_recently(rs, 1000) && gfs2_rgrp_congested(rs->rs_rbm.rgd, loops)) @@ -1871,6 +1886,8 @@ next_rgrp: /* Find the next rgrp, and continue looking */ if (gfs2_select_rgrp(&rs->rs_rbm.rgd, begin)) continue; + if (skip) + continue; /* If we've scanned all the rgrps, but found no free blocks * then this checks for some less likely conditions before |