From 8f79cfcdb65472f1504ade2f53e5f2bfdaeb95da Mon Sep 17 00:00:00 2001 From: Andre Noll Date: Tue, 16 Jun 2009 16:47:10 +1000 Subject: md: raid0: Remove hash spacing and sector shift. The "sector_shift" and "spacing" fields of struct raid0_private_data were only used for the hash table lookups. So the removal of the hash table allows get rid of these fields as well which simplifies create_strip_zones() and raid0_run() quite a bit. Signed-off-by: Andre Noll Signed-off-by: NeilBrown --- drivers/md/raid0.c | 63 +----------------------------------------------------- 1 file changed, 1 insertion(+), 62 deletions(-) (limited to 'drivers/md/raid0.c') diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index d4c9c5d5d7f..edffc4940b4 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -56,7 +56,6 @@ static int create_strip_zones (mddev_t *mddev) { int i, c, j; sector_t curr_zone_end; - sector_t min_spacing; raid0_conf_t *conf = mddev_to_conf(mddev); mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev; struct strip_zone *zone; @@ -202,28 +201,7 @@ static int create_strip_zones (mddev_t *mddev) printk(KERN_INFO "raid0: current zone start: %llu\n", (unsigned long long)smallest->sectors); } - /* Now find appropriate hash spacing. - * We want a number which causes most hash entries to cover - * at most two strips, but the hash table must be at most - * 1 PAGE. We choose the smallest strip, or contiguous collection - * of strips, that has big enough size. We never consider the last - * strip though as it's size has no bearing on the efficacy of the hash - * table. - */ - conf->spacing = curr_zone_end; - min_spacing = curr_zone_end; - sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*)); - for (i=0; i < conf->nr_strip_zones-1; i++) { - sector_t s = 0; - for (j = i; j < conf->nr_strip_zones - 1 && - s < min_spacing; j++) - s += conf->strip_zone[j].sectors; - if (s >= min_spacing && s < conf->spacing) - conf->spacing = s; - } - mddev->queue->unplug_fn = raid0_unplug; - mddev->queue->backing_dev_info.congested_fn = raid0_congested; mddev->queue->backing_dev_info.congested_data = mddev; @@ -273,10 +251,8 @@ static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) return array_sectors; } -static int raid0_run (mddev_t *mddev) +static int raid0_run(mddev_t *mddev) { - unsigned cur=0, i=0, nb_zone; - s64 sectors; raid0_conf_t *conf; if (mddev->chunk_size == 0) { @@ -306,43 +282,6 @@ static int raid0_run (mddev_t *mddev) printk(KERN_INFO "raid0 : md_size is %llu sectors.\n", (unsigned long long)mddev->array_sectors); - printk(KERN_INFO "raid0 : conf->spacing is %llu sectors.\n", - (unsigned long long)conf->spacing); - { - sector_t s = raid0_size(mddev, 0, 0); - sector_t space = conf->spacing; - int round; - conf->sector_shift = 0; - if (sizeof(sector_t) > sizeof(u32)) { - /*shift down space and s so that sector_div will work */ - while (space > (sector_t) (~(u32)0)) { - s >>= 1; - space >>= 1; - s += 1; /* force round-up */ - conf->sector_shift++; - } - } - round = sector_div(s, (u32)space) ? 1 : 0; - nb_zone = s + round; - } - printk(KERN_INFO "raid0 : nb_zone is %d.\n", nb_zone); - sectors = conf->strip_zone[cur].sectors; - - for (i=1; i< nb_zone; i++) { - while (sectors <= conf->spacing) { - cur++; - sectors += conf->strip_zone[cur].sectors; - } - sectors -= conf->spacing; - } - if (conf->sector_shift) { - conf->spacing >>= conf->sector_shift; - /* round spacing up so when we divide by it, we - * err on the side of too-low, which is safest - */ - conf->spacing++; - } - /* calculate the max read-ahead size. * For read-ahead of large files to be effective, we need to * readahead at least twice a whole stripe. i.e. number of devices -- cgit v1.2.3-18-g5258