On Wed, Sep 4, 2013 at 6:47 AM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > 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. > Hi, Johannes Weiner, Thanks for your comment ;) Andrew has pointed this out and this patch is abandoned. -- Regards, Zhan Jianyu -- 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>