Walking backref tree and btrfs quota rely on ulist very much.
This patch tries to use rb_tree to speed up search time.
The original code always checks whether an element
exists before adding a new element, however it costs O(n).
I try to add a rb_tree in the ulist,this is only used to speed up
search. I also do some measurements with quota enabled.
fsstress -p 4 -n 10000
Without this path:
real 0m51.058s 2m4.745s 1m28.222s 1m5.137s
user 0m0.035s 0m0.041s 0m0.105s 0m0.100s
sys 0m12.009s 0m11.246s 0m10.901s 0m10.999s 0m11.287s
With this path:
real 0m55.295s 0m50.960s 1m2.214s 0m48.273s
user 0m0.053s 0m0.095s 0m0.135s 0m0.107s
sys 0m7.766s 0m6.013s 0m6.319s 0m6.030s 0m6.532s
After applying the patch,the execute time is down by ~42%.(11.287s->6.532s)
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Btrfs send/receive uses the aux field to store inode numbers. On
32 bit machines this may become a problem.
Also fix all users of ulist_add and ulist_add_merged.
Reported-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Alexander Block <ablock84@googlemail.com>
We must build up the inode list with the extent lock held after following
indirect refs.
This also requires an extension to ulists, which allows to modify the stored
aux value in case a key already exists in the list.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
ulist_next gets the pointer to the previously returned element to find the
next element from there. However, when we call ulist_add while iteration
with ulist_next is in progress (ulist explicitly supports this), we can
realloc the ulist internal memory, which makes the pointer to the previous
element useless.
Instead, we now use an iterator parameter that's independent from the
internal pointers.
Reported-by: Alexander Block <ablock84@googlemail.com>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
ulist is a generic data structures to hold a collection of unique u64
values. The only operations it supports is adding to the list and
enumerating it.
It is possible to store an auxiliary value along with the key. The
implementation is preliminary and can probably be sped up significantly.
It is used by btrfs_find_all_roots() quota to translate recursions into
iterative loops.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
