On Tue, Mar 28, 2017 at 09:10:35PM +0800, Zhou Chengming wrote: > It's reported that the time of insmoding a klp.ko for one of our > out-tree modules is too long. > > ~ time sudo insmod klp.ko > real 0m23.799s > user 0m0.036s > sys 0m21.256s > > Then we found the reason: our out-tree module used a lot of static local > variables, so klp.ko has a lot of relocation records which reference the > module. Then for each such entry klp_find_object_symbol() is called to > resolve it, but this function uses the interface kallsyms_on_each_symbol() > even for finding module symbols, so will waste a lot of time on walking > through vmlinux kallsyms table many times. > > This patch changes it to use module_kallsyms_on_each_symbol() for modules > symbols. After we apply this patch, the sys time reduced dramatically. > > ~ time sudo insmod klp.ko > real 0m1.007s > user 0m0.032s > sys 0m0.924s > > Signed-off-by: Zhou Chengming <zhouchengming1@xxxxxxxxxx> It would be good to make kallsyms faster, but either way this still a performance improvement for patching modules. Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> -- Josh -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
