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 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/
