From: NeilBrown raid5 rebuild takes stripes so agressively that other access cannot get a look-in. With this patch, the rebuild pauses slightly if there is a shortage of stripes to let other processes have a chance. --- 25-akpm/drivers/md/raid5.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletion(-) diff -puN drivers/md/raid5.c~md-02-rebuild-needs-yield drivers/md/raid5.c --- 25/drivers/md/raid5.c~md-02-rebuild-needs-yield Thu Jan 15 17:36:16 2004 +++ 25-akpm/drivers/md/raid5.c Thu Jan 15 17:36:16 2004 @@ -1395,7 +1395,14 @@ static int sync_request (mddev_t *mddev, first_sector = raid5_compute_sector(stripe*data_disks*sectors_per_chunk + chunk_offset, raid_disks, data_disks, &dd_idx, &pd_idx, conf); - sh = get_active_stripe(conf, sector_nr, pd_idx, 0); + sh = get_active_stripe(conf, sector_nr, pd_idx, 1); + if (sh == NULL) { + sh = get_active_stripe(conf, sector_nr, pd_idx, 0); + /* make sure we don't swamp the stripe cache if someone else + * is trying to get access + */ + yield(); + } spin_lock(&sh->lock); set_bit(STRIPE_SYNCING, &sh->state); clear_bit(STRIPE_INSYNC, &sh->state); _