If the gfp flag used for the memory allocation already has __GFP_ZERO, then there is no need to explicitly clear the "struct devres_node". It is already zeroed. This saves a few cycles when using devm_zalloc() and co. In the case of devres_alloc() (which calls __devres_alloc_node()), the compiler could remove the test and the memset() because it should be able to see that the __GFP_ZERO flag is set. So this would make the code both faster and smaller. Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> --- drivers/base/devres.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 864d0b3f566e..4ab2b50ee38f 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -117,7 +117,9 @@ static __always_inline struct devres * alloc_dr(dr_release_t release, if (unlikely(!dr)) return NULL; - memset(dr, 0, offsetof(struct devres, data)); + /* No need to clear memory twice */ + if (!(gfp & __GFP_ZERO)) + memset(dr, 0, offsetof(struct devres, data)); INIT_LIST_HEAD(&dr->node.entry); dr->node.release = release; -- 2.34.1
