* smallest multiple of the stripe value (sbi->s_stripe) which is
* greater than the default mb_group_prealloc.
*
+ * If "mb_optimize_scan" mount option is set, we maintain in memory group info
+ * structures in two data structures:
+ *
+ * 1) Array of largest free order lists (sbi->s_mb_largest_free_orders)
+ *
+ * Locking: sbi->s_mb_largest_free_orders_locks(array of rw locks)
+ *
+ * This is an array of lists where the index in the array represents the
+ * largest free order in the buddy bitmap of the participating group infos of
+ * that list. So, there are exactly MB_NUM_ORDERS(sb) (which means total
+ * number of buddy bitmap orders possible) number of lists. Group-infos are
+ * placed in appropriate lists.
+ *
+ * 2) Average fragment size rb tree (sbi->s_mb_avg_fragment_size_root)
+ *
+ * Locking: sbi->s_mb_rb_lock (rwlock)
+ *
+ * This is a red black tree consisting of group infos and the tree is sorted
+ * by average fragment sizes (which is calculated as ext4_group_info->bb_free
+ * / ext4_group_info->bb_fragments).
+ *
+ * When "mb_optimize_scan" mount option is set, mballoc consults the above data
+ * structures to decide the order in which groups are to be traversed for
+ * fulfilling an allocation request.
+ *
+ * At CR = 0, we look for groups which have the largest_free_order >= the order
+ * of the request. We directly look at the largest free order list in the data
+ * structure (1) above where largest_free_order = order of the request. If that
+ * list is empty, we look at remaining list in the increasing order of
+ * largest_free_order. This allows us to perform CR = 0 lookup in O(1) time.
+ *
+ * At CR = 1, we only consider groups where average fragment size > request
+ * size. So, we lookup a group which has average fragment size just above or
+ * equal to request size using our rb tree (data structure 2) in O(log N) time.
+ *
+ * If "mb_optimize_scan" mount option is not set, mballoc traverses groups in
+ * linear order which requires O(N) search time for each CR 0 and CR 1 phase.
+ *
* The regular allocator (using the buddy cache) supports a few tunables.
*
* /sys/fs/ext4/<partition>/mb_min_to_scan
* /sys/fs/ext4/<partition>/mb_max_to_scan
* /sys/fs/ext4/<partition>/mb_order2_req
+ * /sys/fs/ext4/<partition>/mb_linear_limit
*
* The regular allocator uses buddy scan only if the request len is power of
* 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
* can be used for allocation. ext4_mb_good_group explains how the groups are
* checked.
*
+ * When "mb_optimize_scan" is turned on, as mentioned above, the groups may not
+ * get traversed linearly. That may result in subsequent allocations being not
+ * close to each other. And so, the underlying device may get filled up in a
+ * non-linear fashion. While that may not matter on non-rotational devices, for
+ * rotational devices that may result in higher seek times. "mb_linear_limit"
+ * tells mballoc how many groups mballoc should search linearly before
+ * performing consulting above data structures for more efficient lookups. For
+ * non rotational devices, this value defaults to 0 and for rotational devices
+ * this is set to MB_DEFAULT_LINEAR_LIMIT.
+ *
* Both the prealloc space are getting populated as above. So for the first
* request we will hit the buddy cache which will result in this prealloc
* space getting filled. The prealloc space is then later used for the
* - bitlock on a group (group)
* - object (inode/locality) (object)
* - per-pa lock (pa)
+ * - cr0 lists lock (cr0)
+ * - cr1 tree lock (cr1)
*
* Paths:
* - new pa
* group
* object
*
+ * - allocation path (ext4_mb_regular_allocator)
+ * group
+ * cr0/cr1
*/
static struct kmem_cache *ext4_pspace_cachep;
static struct kmem_cache *ext4_ac_cachep;
ext4_group_t group);
static void ext4_mb_new_preallocation(struct ext4_allocation_context *ac);
+static bool ext4_mb_good_group(struct ext4_allocation_context *ac,
+ ext4_group_t group, int cr);
+
/*
* The algorithm using this percpu seq counter goes below:
* 1. We sample the percpu discard_pa_seq counter before trying for block
}
}
+static void ext4_mb_rb_insert(struct rb_root *root, struct rb_node *new,
+ int (*cmp)(struct rb_node *, struct rb_node *))
+{
+ struct rb_node **iter = &root->rb_node, *parent = NULL;
+
+ while (*iter) {
+ parent = *iter;
+ if (cmp(new, *iter) > 0)
+ iter = &((*iter)->rb_left);
+ else
+ iter = &((*iter)->rb_right);
+ }
+
+ rb_link_node(new, parent, iter);
+ rb_insert_color(new, root);
+}
+
+static int
+ext4_mb_avg_fragment_size_cmp(struct rb_node *rb1, struct rb_node *rb2)
+{
+ struct ext4_group_info *grp1 = rb_entry(rb1,
+ struct ext4_group_info,
+ bb_avg_fragment_size_rb);
+ struct ext4_group_info *grp2 = rb_entry(rb2,
+ struct ext4_group_info,
+ bb_avg_fragment_size_rb);
+ int num_frags_1, num_frags_2;
+
+ num_frags_1 = grp1->bb_fragments ?
+ grp1->bb_free / grp1->bb_fragments : 0;
+ num_frags_2 = grp2->bb_fragments ?
+ grp2->bb_free / grp2->bb_fragments : 0;
+
+ return (num_frags_2 - num_frags_1);
+}
+
+/*
+ * Reinsert grpinfo into the avg_fragment_size tree with new average
+ * fragment size.
+ */
+static void
+mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+ if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0)
+ return;
+
+ write_lock(&sbi->s_mb_rb_lock);
+ if (!RB_EMPTY_NODE(&grp->bb_avg_fragment_size_rb)) {
+ rb_erase(&grp->bb_avg_fragment_size_rb,
+ &sbi->s_mb_avg_fragment_size_root);
+ RB_CLEAR_NODE(&grp->bb_avg_fragment_size_rb);
+ }
+
+ ext4_mb_rb_insert(&sbi->s_mb_avg_fragment_size_root,
+ &grp->bb_avg_fragment_size_rb,
+ ext4_mb_avg_fragment_size_cmp);
+ write_unlock(&sbi->s_mb_rb_lock);
+}
+
+/*
+ * Choose next group by traversing largest_free_order lists. Updates *new_cr if
+ * cr level needs an update.
+ */
+static void ext4_mb_choose_next_group_cr0(struct ext4_allocation_context *ac,
+ int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ struct ext4_group_info *iter, *grp;
+ int i;
+
+ if (ac->ac_status == AC_STATUS_FOUND)
+ return;
+
+ if (unlikely(sbi->s_mb_stats && ac->ac_flags & EXT4_MB_CR0_OPTIMIZED))
+ atomic_inc(&sbi->s_bal_cr0_bad_suggestions);
+
+ grp = NULL;
+ for (i = ac->ac_2order; i < MB_NUM_ORDERS(ac->ac_sb); i++) {
+ if (list_empty(&sbi->s_mb_largest_free_orders[i]))
+ continue;
+ read_lock(&sbi->s_mb_largest_free_orders_locks[i]);
+ if (list_empty(&sbi->s_mb_largest_free_orders[i])) {
+ read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
+ continue;
+ }
+ grp = NULL;
+ list_for_each_entry(iter, &sbi->s_mb_largest_free_orders[i],
+ bb_largest_free_order_node) {
+ if (sbi->s_mb_stats)
+ atomic64_inc(&sbi->s_bal_cX_groups_considered[0]);
+ if (likely(ext4_mb_good_group(ac, iter->bb_group, 0))) {
+ grp = iter;
+ break;
+ }
+ }
+ read_unlock(&sbi->s_mb_largest_free_orders_locks[i]);
+ if (grp)
+ break;
+ }
+
+ if (!grp) {
+ /* Increment cr and search again */
+ *new_cr = 1;
+ } else {
+ *group = grp->bb_group;
+ ac->ac_last_optimal_group = *group;
+ ac->ac_flags |= EXT4_MB_CR0_OPTIMIZED;
+ }
+}
+
+/*
+ * Choose next group by traversing average fragment size tree. Updates *new_cr
+ * if cr lvel needs an update. Sets EXT4_MB_SEARCH_NEXT_LINEAR to indicate that
+ * the linear search should continue for one iteration since there's lock
+ * contention on the rb tree lock.
+ */
+static void ext4_mb_choose_next_group_cr1(struct ext4_allocation_context *ac,
+ int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
+{
+ struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+ int avg_fragment_size, best_so_far;
+ struct rb_node *node, *found;
+ struct ext4_group_info *grp;
+
+ /*
+ * If there is contention on the lock, instead of waiting for the lock
+ * to become available, just continue searching lineraly. We'll resume
+ * our rb tree search later starting at ac->ac_last_optimal_group.
+ */
+ if (!read_trylock(&sbi->s_mb_rb_lock)) {
+ ac->ac_flags |= EXT4_MB_SEARCH_NEXT_LINEAR;
+ return;
+ }
+
+ if (unlikely(ac->ac_flags & EXT4_MB_CR1_OPTIMIZED)) {
+ if (sbi->s_mb_stats)
+ atomic_inc(&sbi->s_bal_cr1_bad_suggestions);
+ /* We have found something at CR 1 in the past */
+ grp = ext4_get_group_info(ac->ac_sb, ac->ac_last_optimal_group);
+ for (found = rb_next(&grp->bb_avg_fragment_size_rb); found != NULL;
+ found = rb_next(found)) {
+ grp = rb_entry(found, struct ext4_group_info,
+ bb_avg_fragment_size_rb);
+ if (sbi->s_mb_stats)
+ atomic64_inc(&sbi->s_bal_cX_groups_considered[1]);
+ if (likely(ext4_mb_good_group(ac, grp->bb_group, 1)))
+ break;
+ }
+ goto done;
+ }
+
+ node = sbi->s_mb_avg_fragment_size_root.rb_node;
+ best_so_far = 0;
+ found = NULL;
+
+ while (node) {
+ grp = rb_entry(node, struct ext4_group_info,
+ bb_avg_fragment_size_rb);
+ avg_fragment_size = 0;
+ if (ext4_mb_good_group(ac, grp->bb_group, 1)) {
+ avg_fragment_size = grp->bb_fragments ?
+ grp->bb_free / grp->bb_fragments : 0;
+ if (!best_so_far || avg_fragment_size < best_so_far) {
+ best_so_far = avg_fragment_size;
+ found = node;
+ }
+ }
+ if (avg_fragment_size > ac->ac_g_ex.fe_len)
+ node = node->rb_right;
+ else
+ node = node->rb_left;
+ }
+
+done:
+ if (found) {
+ grp = rb_entry(found, struct ext4_group_info,
+ bb_avg_fragment_size_rb);
+ *group = grp->bb_group;
+ ac->ac_flags |= EXT4_MB_CR1_OPTIMIZED;
+ } else {
+ *new_cr = 2;
+ }
+
+ read_unlock(&sbi->s_mb_rb_lock);
+ ac->ac_last_optimal_group = *group;
+}
+
+static inline int should_optimize_scan(struct ext4_allocation_context *ac)
+{
+ if (unlikely(!test_opt2(ac->ac_sb, MB_OPTIMIZE_SCAN)))
+ return 0;
+ if (ac->ac_criteria >= 2)
+ return 0;
+ if (ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))
+ return 0;
+ return 1;
+}
+
+/*
+ * Return next linear group for allocation. If linear traversal should not be
+ * performed, this function just returns the same group
+ */
+static int
+next_linear_group(struct ext4_allocation_context *ac, int group, int ngroups)
+{
+ if (!should_optimize_scan(ac))
+ goto inc_and_return;
+
+ if (ac->ac_groups_linear_remaining) {
+ ac->ac_groups_linear_remaining--;
+ goto inc_and_return;
+ }
+
+ if (ac->ac_flags & EXT4_MB_SEARCH_NEXT_LINEAR) {
+ ac->ac_flags &= ~EXT4_MB_SEARCH_NEXT_LINEAR;
+ goto inc_and_return;
+ }
+
+ return group;
+inc_and_return:
+ /*
+ * Artificially restricted ngroups for non-extent
+ * files makes group > ngroups possible on first loop.
+ */
+ return group + 1 >= ngroups ? 0 : group + 1;
+}
+
+/*
+ * ext4_mb_choose_next_group: choose next group for allocation.
+ *
+ * @ac Allocation Context
+ * @new_cr This is an output parameter. If the there is no good group
+ * available at current CR level, this field is updated to indicate
+ * the new cr level that should be used.
+ * @group This is an input / output parameter. As an input it indicates the
+ * next group that the allocator intends to use for allocation. As
+ * output, this field indicates the next group that should be used as
+ * determined by the optimization functions.
+ * @ngroups Total number of groups
+ */
+static void ext4_mb_choose_next_group(struct ext4_allocation_context *ac,
+ int *new_cr, ext4_group_t *group, ext4_group_t ngroups)
+{
+ *new_cr = ac->ac_criteria;
+
+ if (!should_optimize_scan(ac) || ac->ac_groups_linear_remaining)
+ return;
+
+ if (*new_cr == 0) {
+ ext4_mb_choose_next_group_cr0(ac, new_cr, group, ngroups);
+ } else if (*new_cr == 1) {
+ ext4_mb_choose_next_group_cr1(ac, new_cr, group, ngroups);
+ } else {
+ /*
+ * TODO: For CR=2, we can arrange groups in an rb tree sorted by
+ * bb_free. But until that happens, we should never come here.
+ */
+ WARN_ON(1);
+ }
+}
+
/*
* Cache the order of the largest free extent we have available in this block
* group.
static void
mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp)
{
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
int i;
- int bits;
+ if (test_opt2(sb, MB_OPTIMIZE_SCAN) && grp->bb_largest_free_order >= 0) {
+ write_lock(&sbi->s_mb_largest_free_orders_locks[
+ grp->bb_largest_free_order]);
+ list_del_init(&grp->bb_largest_free_order_node);
+ write_unlock(&sbi->s_mb_largest_free_orders_locks[
+ grp->bb_largest_free_order]);
+ }
grp->bb_largest_free_order = -1; /* uninit */
- bits = MB_NUM_ORDERS(sb) - 1;
- for (i = bits; i >= 0; i--) {
+ for (i = MB_NUM_ORDERS(sb) - 1; i >= 0; i--) {
if (grp->bb_counters[i] > 0) {
grp->bb_largest_free_order = i;
break;
}
}
+ if (test_opt2(sb, MB_OPTIMIZE_SCAN) &&
+ grp->bb_largest_free_order >= 0 && grp->bb_free) {
+ write_lock(&sbi->s_mb_largest_free_orders_locks[
+ grp->bb_largest_free_order]);
+ list_add_tail(&grp->bb_largest_free_order_node,
+ &sbi->s_mb_largest_free_orders[grp->bb_largest_free_order]);
+ write_unlock(&sbi->s_mb_largest_free_orders_locks[
+ grp->bb_largest_free_order]);
+ }
}
static noinline_for_stack
period = get_cycles() - period;
atomic_inc(&sbi->s_mb_buddies_generated);
atomic64_add(period, &sbi->s_mb_generation_time);
+ mb_update_avg_fragment_size(sb, grp);
}
/* The buddy information is attached the buddy cache inode
done:
mb_set_largest_free_order(sb, e4b->bd_info);
+ mb_update_avg_fragment_size(sb, e4b->bd_info);
mb_check_buddy(e4b);
}
}
mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);
+ mb_update_avg_fragment_size(e4b->bd_sb, e4b->bd_info);
ext4_set_bits(e4b->bd_bitmap, ex->fe_start, len0);
mb_check_buddy(e4b);
* from the goal value specified
*/
group = ac->ac_g_ex.fe_group;
+ ac->ac_last_optimal_group = group;
+ ac->ac_groups_linear_remaining = sbi->s_mb_max_linear_groups;
prefetch_grp = group;
- for (i = 0; i < ngroups; group++, i++) {
- int ret = 0;
+ for (i = 0; i < ngroups; group = next_linear_group(ac, group, ngroups),
+ i++) {
+ int ret = 0, new_cr;
+
cond_resched();
- /*
- * Artificially restricted ngroups for non-extent
- * files makes group > ngroups possible on first loop.
- */
- if (group >= ngroups)
- group = 0;
+
+ ext4_mb_choose_next_group(ac, &new_cr, &group, ngroups);
+ if (new_cr != cr) {
+ cr = new_cr;
+ goto repeat;
+ }
/*
* Batch reads of the block allocation bitmaps
atomic64_read(&sbi->s_bal_cX_groups_considered[0]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[0]));
+ seq_printf(seq, "\t\tbad_suggestions: %u\n",
+ atomic_read(&sbi->s_bal_cr0_bad_suggestions));
seq_puts(seq, "\tcr1_stats:\n");
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[1]));
atomic64_read(&sbi->s_bal_cX_groups_considered[1]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[1]));
+ seq_printf(seq, "\t\tbad_suggestions: %u\n",
+ atomic_read(&sbi->s_bal_cr1_bad_suggestions));
seq_puts(seq, "\tcr2_stats:\n");
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[2]));
INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
init_rwsem(&meta_group_info[i]->alloc_sem);
meta_group_info[i]->bb_free_root = RB_ROOT;
+ INIT_LIST_HEAD(&meta_group_info[i]->bb_largest_free_order_node);
+ RB_CLEAR_NODE(&meta_group_info[i]->bb_avg_fragment_size_rb);
meta_group_info[i]->bb_largest_free_order = -1; /* uninit */
+ meta_group_info[i]->bb_group = group;
mb_group_bb_bitmap_alloc(sb, meta_group_info[i], group);
return 0;
i++;
} while (i < MB_NUM_ORDERS(sb));
+ sbi->s_mb_avg_fragment_size_root = RB_ROOT;
+ sbi->s_mb_largest_free_orders =
+ kmalloc_array(MB_NUM_ORDERS(sb), sizeof(struct list_head),
+ GFP_KERNEL);
+ if (!sbi->s_mb_largest_free_orders) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ sbi->s_mb_largest_free_orders_locks =
+ kmalloc_array(MB_NUM_ORDERS(sb), sizeof(rwlock_t),
+ GFP_KERNEL);
+ if (!sbi->s_mb_largest_free_orders_locks) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ for (i = 0; i < MB_NUM_ORDERS(sb); i++) {
+ INIT_LIST_HEAD(&sbi->s_mb_largest_free_orders[i]);
+ rwlock_init(&sbi->s_mb_largest_free_orders_locks[i]);
+ }
+ rwlock_init(&sbi->s_mb_rb_lock);
spin_lock_init(&sbi->s_md_lock);
sbi->s_mb_free_pending = 0;
spin_lock_init(&lg->lg_prealloc_lock);
}
+ if (blk_queue_nonrot(bdev_get_queue(sb->s_bdev)))
+ sbi->s_mb_max_linear_groups = 0;
+ else
+ sbi->s_mb_max_linear_groups = MB_DEFAULT_LINEAR_LIMIT;
/* init file for buddy data */
ret = ext4_mb_init_backend(sb);
if (ret != 0)
free_percpu(sbi->s_locality_groups);
sbi->s_locality_groups = NULL;
out:
+ kfree(sbi->s_mb_largest_free_orders);
+ kfree(sbi->s_mb_largest_free_orders_locks);
kfree(sbi->s_mb_offsets);
sbi->s_mb_offsets = NULL;
kfree(sbi->s_mb_maxs);
kvfree(group_info);
rcu_read_unlock();
}
+ kfree(sbi->s_mb_largest_free_orders);
+ kfree(sbi->s_mb_largest_free_orders_locks);
kfree(sbi->s_mb_offsets);
kfree(sbi->s_mb_maxs);
iput(sbi->s_buddy_cache);
Opt_dioread_nolock, Opt_dioread_lock,
Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
- Opt_prefetch_block_bitmaps,
+ Opt_prefetch_block_bitmaps, Opt_mb_optimize_scan,
#ifdef CONFIG_EXT4_DEBUG
Opt_fc_debug_max_replay, Opt_fc_debug_force
#endif
{Opt_nombcache, "nombcache"},
{Opt_nombcache, "no_mbcache"}, /* for backward compatibility */
{Opt_prefetch_block_bitmaps, "prefetch_block_bitmaps"},
+ {Opt_mb_optimize_scan, "mb_optimize_scan=%d"},
{Opt_removed, "check=none"}, /* mount option from ext2/3 */
{Opt_removed, "nocheck"}, /* mount option from ext2/3 */
{Opt_removed, "reservation"}, /* mount option from ext2/3 */
}
#define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
+#define DEFAULT_MB_OPTIMIZE_SCAN (-1)
+
static const char deprecated_msg[] =
"Mount option \"%s\" will be removed by %s\n"
"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
MOPT_SET},
+ {Opt_mb_optimize_scan, EXT4_MOUNT2_MB_OPTIMIZE_SCAN, MOPT_GTE0},
#ifdef CONFIG_EXT4_DEBUG
{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
struct ext4_parsed_options {
unsigned long journal_devnum;
unsigned int journal_ioprio;
+ int mb_optimize_scan;
};
static int handle_mount_opt(struct super_block *sb, char *opt, int token,
sbi->s_mount_opt |= m->mount_opt;
} else if (token == Opt_data_err_ignore) {
sbi->s_mount_opt &= ~m->mount_opt;
+ } else if (token == Opt_mb_optimize_scan) {
+ if (arg != 0 && arg != 1) {
+ ext4_msg(sb, KERN_WARNING,
+ "mb_optimize_scan should be set to 0 or 1.");
+ return -1;
+ }
+ parsed_opts->mb_optimize_scan = arg;
} else {
if (!args->from)
arg = 1;
/* Set defaults for the variables that will be set during parsing */
parsed_opts.journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
parsed_opts.journal_devnum = 0;
+ parsed_opts.mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
if ((data && !orig_data) || !sbi)
goto out_free_base;
ext4_fc_replay_cleanup(sb);
ext4_ext_init(sb);
+
+ /*
+ * Enable optimize_scan if number of groups is > threshold. This can be
+ * turned off by passing "mb_optimize_scan=0". This can also be
+ * turned on forcefully by passing "mb_optimize_scan=1".
+ */
+ if (parsed_opts.mb_optimize_scan == 1)
+ set_opt2(sb, MB_OPTIMIZE_SCAN);
+ else if (parsed_opts.mb_optimize_scan == 0)
+ clear_opt2(sb, MB_OPTIMIZE_SCAN);
+ else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD)
+ set_opt2(sb, MB_OPTIMIZE_SCAN);
+
err = ext4_mb_init(sb);
if (err) {
ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
projects / users / jedix / linux-maple.git / commitdiff