The ida callers always calls ida_pre_get() before ida_get_new*(). ida_pre_get() will always do layer allocation, which means the layer removal in ida_get_new*() is helpless. ida_get_new*() frees and the ida_pre_get() for the next ida_get_new*() allocates.
It causes an unneeded ping-pong. The aim "Throw away extra resources one by one" can't be achieved. This 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 <la...@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 317fd35..25fe476 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/