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authorZhou Chengming <zhouchengming1@huawei.com>2017-03-28 21:10:35 +0800
committerJiri Kosina <jkosina@suse.cz>2017-03-30 10:41:38 +0200
commit72f04b50d61c81a2cc3065d3b973e83827760515 (patch)
tree41c7a9716078c4aef3947be131d1c308094de97a
parentc1ae3cfa0e89fa1a7ecc4c99031f5e9ae99d9201 (diff)
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op-kernel-dev-72f04b50d61c81a2cc3065d3b973e83827760515.tar.gz
livepatch: Reduce the time of finding module symbols
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@huawei.com> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Jessica Yu <jeyu@redhat.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--kernel/livepatch/core.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index af46438..b4b8bb0 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -182,7 +182,10 @@ static int klp_find_object_symbol(const char *objname, const char *name,
};
mutex_lock(&module_mutex);
- kallsyms_on_each_symbol(klp_find_callback, &args);
+ if (objname)
+ module_kallsyms_on_each_symbol(klp_find_callback, &args);
+ else
+ kallsyms_on_each_symbol(klp_find_callback, &args);
mutex_unlock(&module_mutex);
/*
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