| Message ID | 20170111002522.GB68360@ast-mbp.thefacebook.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, Jan 10, 2017 at 04:25:23PM -0800, Alexei Starovoitov wrote: > On Tue, Jan 10, 2017 at 03:02:07PM +0100, Tobias Klauser wrote: > > Remove the unused but set variable 'first_node' in > > __bpf_lru_list_shrink_inactive() to fix the following GCC warning when > > building with 'W=1': > > > > kernel/bpf/bpf_lru_list.c:216:41: warning: variable ‘first_node’ set but not used [-Wunused-but-set-variable] > > > > Cc: Martin KaFai Lau <kafai@fb.com> > > Signed-off-by: Tobias Klauser <tklauser@distanz.ch> > > --- > > kernel/bpf/bpf_lru_list.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/kernel/bpf/bpf_lru_list.c b/kernel/bpf/bpf_lru_list.c > > index 89b7ef41c86b..d78501ee0609 100644 > > --- a/kernel/bpf/bpf_lru_list.c > > +++ b/kernel/bpf/bpf_lru_list.c > > @@ -213,11 +213,10 @@ __bpf_lru_list_shrink_inactive(struct bpf_lru *lru, > > enum bpf_lru_list_type tgt_free_type) > > { > > struct list_head *inactive = &l->lists[BPF_LRU_LIST_T_INACTIVE]; > > - struct bpf_lru_node *node, *tmp_node, *first_node; > > + struct bpf_lru_node *node, *tmp_node; > > unsigned int nshrinked = 0; > > unsigned int i = 0; > > > > - first_node = list_first_entry(inactive, struct bpf_lru_node, list); > > list_for_each_entry_safe_reverse(node, tmp_node, inactive, list) { > > if (bpf_lru_node_is_ref(node)) { > > __bpf_lru_node_move(l, node, BPF_LRU_LIST_T_ACTIVE); > > Martin, > I cannot tell whether it's actually copy-paste leftover > or this patch is needed: I made some changes to __bpf_lru_list_shrink_inactive() which made first_node checking unnecessary but I did not remove first_node all together by mistake. __bpf_lru_list_rotate_active() pushes node back to the head, so we need to remember the original first_node and break accordingly. __bpf_lru_list_shrink_inactive() does not do that, so there is no need to test against first_node.
diff --git a/kernel/bpf/bpf_lru_list.c b/kernel/bpf/bpf_lru_list.c index 89b7ef41c86b..b9255a427c28 100644 --- a/kernel/bpf/bpf_lru_list.c +++ b/kernel/bpf/bpf_lru_list.c @@ -229,6 +229,7 @@ __bpf_lru_list_shrink_inactive(struct bpf_lru *lru, } if (++i == lru->nr_scans) + if (++i == lru->nr_scans || node == first_node) break; }