On Mon, Aug 26, 2013 at 09:36:58PM +0800, larmbr wrote: > Currently, we get the vm_swappiness via vmscan_swappiness(), which > calls global_reclaim() to check if this is a global reclaim. > > Besides, the current implementation of global_reclaim() always returns > true for the !CONFIG_MEGCG case, and judges the other case by checking > whether scan_control->target_mem_cgroup is null or not. > > Thus, we could just use two versions of vmscan_swappiness() based on > MEMCG Kconfig , to eliminate the unnecessary run-time cost for > the !CONFIG_MEMCG at all, and to squash all memcg-related checking > into the CONFIG_MEMCG version. The compiler can easily detect that global_reclaim() always returns true for !CONFIG_MEMCG during compile time and not even generate a branch for this. > 2 files changed, 12 insertions(+), 3 deletions(-) You're adding more code for now gain. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>