Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [PATCH 6/8] idr: avoid ping-pong | Date | Fri, 18 Apr 2014 20:49:53 +0800 |
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The ida callers always calls ida_pre_get() before ida_get_new*(). ida_pre_get() will do layer allocation, and ida_get_new*() will do layer removal.
It causes an unneeded ping-pong. The speculative layer removal in ida_get_new*() can't result expected optimization.
So we remove the unneeded layer removal in ida_get_new*().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- lib/idr.c | 11 ----------- 1 files changed, 0 insertions(+), 11 deletions(-)
diff --git a/lib/idr.c b/lib/idr.c index e4f9965..be0b6ff 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -1001,17 +1001,6 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) *p_id = id; - /* Each leaf node can handle nearly a thousand slots and the - * whole idea of ida is to have small memory foot print. - * Throw away extra resources one by one after each successful - * allocation. - */ - if (ida->idr.id_free_cnt || ida->free_bitmap) { - struct idr_layer *p = get_from_free_list(&ida->idr); - if (p) - kmem_cache_free(idr_layer_cache, p); - } - return 0; } EXPORT_SYMBOL(ida_get_new_above); -- 1.7.4.4
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