From 1e8f915868c59be4d6e49d9aff928454a5d5d569 Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Mon, 6 May 2013 11:03:27 +0000 Subject: [PATCH] Btrfs: introduce qgroup_ulist to avoid frequently allocating/freeing ulist When doing qgroup accounting, we call ulist_alloc()/ulist_free() every time when we want to walk qgroup tree. By introducing 'qgroup_ulist', we only need to call ulist_alloc()/ulist_free() once. This reduce some sys time to allocate memory, see the measurements below fsstress -p 4 -n 10000 -d $dir With this patch: real 0m50.153s user 0m0.081s sys 0m6.294s real 0m51.113s user 0m0.092s sys 0m6.220s real 0m52.610s user 0m0.096s sys 0m6.125s avg 6.213 ----------------------------------------------------- Without the patch: real 0m54.825s user 0m0.061s sys 0m10.665s real 1m6.401s user 0m0.089s sys 0m11.218s real 1m13.768s user 0m0.087s sys 0m10.665s avg 10.849 we can see the sys time reduce ~43%. Signed-off-by: Wang Shilong Signed-off-by: Josef Bacik --- fs/btrfs/ctree.h | 6 ++++ fs/btrfs/disk-io.c | 1 + fs/btrfs/qgroup.c | 70 ++++++++++++++++++++++++---------------------- 3 files changed, 43 insertions(+), 34 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d6dd49b51ba8..a365400e38da 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1594,6 +1594,12 @@ struct btrfs_fs_info { struct rb_root qgroup_tree; spinlock_t qgroup_lock; + /* + * used to avoid frequently calling ulist_alloc()/ulist_free() + * when doing qgroup accounting, it must be protected by qgroup_lock. + */ + struct ulist *qgroup_ulist; + /* protect user change for quota operations */ struct mutex qgroup_ioctl_lock; diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index aecf788ed81e..df5169b7aad1 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2274,6 +2274,7 @@ int open_ctree(struct super_block *sb, fs_info->qgroup_seq = 1; fs_info->quota_enabled = 0; fs_info->pending_quota_state = 0; + fs_info->qgroup_ulist = NULL; mutex_init(&fs_info->qgroup_rescan_lock); btrfs_init_free_cluster(&fs_info->meta_alloc_cluster); diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 9d49c586995a..7f38cce2528d 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -259,6 +259,12 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) if (!fs_info->quota_enabled) return 0; + fs_info->qgroup_ulist = ulist_alloc(GFP_NOFS); + if (!fs_info->qgroup_ulist) { + ret = -ENOMEM; + goto out; + } + path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; @@ -424,6 +430,9 @@ int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) } btrfs_free_path(path); + if (ret) + ulist_free(fs_info->qgroup_ulist); + return ret < 0 ? ret : 0; } @@ -460,6 +469,7 @@ void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info) } kfree(qgroup); } + ulist_free(fs_info->qgroup_ulist); } static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, @@ -819,6 +829,12 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans, goto out; } + fs_info->qgroup_ulist = ulist_alloc(GFP_NOFS); + if (!fs_info->qgroup_ulist) { + ret = -ENOMEM; + goto out; + } + /* * initially create the quota tree */ @@ -916,6 +932,8 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans, kfree(quota_root); } out: + if (ret) + ulist_free(fs_info->qgroup_ulist); mutex_unlock(&fs_info->qgroup_ioctl_lock); return ret; } @@ -1355,7 +1373,6 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, u64 ref_root; struct btrfs_qgroup *qgroup; struct ulist *roots = NULL; - struct ulist *tmp = NULL; u64 seq; int ret = 0; int sgn; @@ -1448,31 +1465,28 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, /* * step 1: for each old ref, visit all nodes once and inc refcnt */ - tmp = ulist_alloc(GFP_ATOMIC); - if (!tmp) { - ret = -ENOMEM; - goto unlock; - } + ulist_reinit(fs_info->qgroup_ulist); seq = fs_info->qgroup_seq; fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */ - ret = qgroup_account_ref_step1(fs_info, roots, tmp, seq); + ret = qgroup_account_ref_step1(fs_info, roots, fs_info->qgroup_ulist, + seq); if (ret) goto unlock; /* * step 2: walk from the new root */ - ret = qgroup_account_ref_step2(fs_info, roots, tmp, seq, sgn, - node->num_bytes, qgroup); + ret = qgroup_account_ref_step2(fs_info, roots, fs_info->qgroup_ulist, + seq, sgn, node->num_bytes, qgroup); if (ret) goto unlock; /* * step 3: walk again from old refs */ - ret = qgroup_account_ref_step3(fs_info, roots, tmp, seq, sgn, - node->num_bytes); + ret = qgroup_account_ref_step3(fs_info, roots, fs_info->qgroup_ulist, + seq, sgn, node->num_bytes); if (ret) goto unlock; @@ -1480,7 +1494,6 @@ int btrfs_qgroup_account_ref(struct btrfs_trans_handle *trans, spin_unlock(&fs_info->qgroup_lock); mutex_unlock(&fs_info->qgroup_rescan_lock); ulist_free(roots); - ulist_free(tmp); return ret; } @@ -1720,7 +1733,6 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes) struct btrfs_fs_info *fs_info = root->fs_info; u64 ref_root = root->root_key.objectid; int ret = 0; - struct ulist *ulist = NULL; struct ulist_node *unode; struct ulist_iterator uiter; @@ -1743,17 +1755,13 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes) * in a first step, we check all affected qgroups if any limits would * be exceeded */ - ulist = ulist_alloc(GFP_ATOMIC); - if (!ulist) { - ret = -ENOMEM; - goto out; - } - ret = ulist_add(ulist, qgroup->qgroupid, + ulist_reinit(fs_info->qgroup_ulist); + ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC); if (ret < 0) goto out; ULIST_ITER_INIT(&uiter); - while ((unode = ulist_next(ulist, &uiter))) { + while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) { struct btrfs_qgroup *qg; struct btrfs_qgroup_list *glist; @@ -1774,7 +1782,8 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes) } list_for_each_entry(glist, &qg->groups, next_group) { - ret = ulist_add(ulist, glist->group->qgroupid, + ret = ulist_add(fs_info->qgroup_ulist, + glist->group->qgroupid, (uintptr_t)glist->group, GFP_ATOMIC); if (ret < 0) goto out; @@ -1785,7 +1794,7 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes) * no limits exceeded, now record the reservation into all qgroups */ ULIST_ITER_INIT(&uiter); - while ((unode = ulist_next(ulist, &uiter))) { + while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) { struct btrfs_qgroup *qg; qg = (struct btrfs_qgroup *)(uintptr_t)unode->aux; @@ -1795,8 +1804,6 @@ int btrfs_qgroup_reserve(struct btrfs_root *root, u64 num_bytes) out: spin_unlock(&fs_info->qgroup_lock); - ulist_free(ulist); - return ret; } @@ -1805,7 +1812,6 @@ void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes) struct btrfs_root *quota_root; struct btrfs_qgroup *qgroup; struct btrfs_fs_info *fs_info = root->fs_info; - struct ulist *ulist = NULL; struct ulist_node *unode; struct ulist_iterator uiter; u64 ref_root = root->root_key.objectid; @@ -1827,17 +1833,13 @@ void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes) if (!qgroup) goto out; - ulist = ulist_alloc(GFP_ATOMIC); - if (!ulist) { - btrfs_std_error(fs_info, -ENOMEM); - goto out; - } - ret = ulist_add(ulist, qgroup->qgroupid, + ulist_reinit(fs_info->qgroup_ulist); + ret = ulist_add(fs_info->qgroup_ulist, qgroup->qgroupid, (uintptr_t)qgroup, GFP_ATOMIC); if (ret < 0) goto out; ULIST_ITER_INIT(&uiter); - while ((unode = ulist_next(ulist, &uiter))) { + while ((unode = ulist_next(fs_info->qgroup_ulist, &uiter))) { struct btrfs_qgroup *qg; struct btrfs_qgroup_list *glist; @@ -1846,7 +1848,8 @@ void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes) qg->reserved -= num_bytes; list_for_each_entry(glist, &qg->groups, next_group) { - ret = ulist_add(ulist, glist->group->qgroupid, + ret = ulist_add(fs_info->qgroup_ulist, + glist->group->qgroupid, (uintptr_t)glist->group, GFP_ATOMIC); if (ret < 0) goto out; @@ -1855,7 +1858,6 @@ void btrfs_qgroup_free(struct btrfs_root *root, u64 num_bytes) out: spin_unlock(&fs_info->qgroup_lock); - ulist_free(ulist); } void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)