From: Hui Zhu <zhuhui@kylinos.cn>
Replace hardcoded enum values with bpf_core_enum_value() calls in
cgroup_iter_memcg test to improve portability across different
kernel versions.
The change adds runtime enum value resolution for:
- node_stat_item: NR_ANON_MAPPED, NR_SHMEM, NR_FILE_PAGES,
NR_FILE_MAPPED
- memcg_stat_item: MEMCG_KMEM
- vm_event_item: PGFAULT
This ensures the BPF program can adapt to enum value changes
between kernel versions, returning early if any enum value is
unavailable (returns 0).
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
---
.../selftests/bpf/progs/cgroup_iter_memcg.c | 41 +++++++++++++++----
1 file changed, 34 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
index 59fb70a3cc50..b020951dd7e6 100644
--- a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
+++ b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c
@@ -15,6 +15,8 @@ int cgroup_memcg_query(struct bpf_iter__cgroup *ctx)
struct cgroup *cgrp = ctx->cgroup;
struct cgroup_subsys_state *css;
struct mem_cgroup *memcg;
+ int ret = 1;
+ int idx;
if (!cgrp)
return 1;
@@ -26,14 +28,39 @@ int cgroup_memcg_query(struct bpf_iter__cgroup *ctx)
bpf_mem_cgroup_flush_stats(memcg);
- memcg_query.nr_anon_mapped = bpf_mem_cgroup_page_state(memcg, NR_ANON_MAPPED);
- memcg_query.nr_shmem = bpf_mem_cgroup_page_state(memcg, NR_SHMEM);
- memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(memcg, NR_FILE_PAGES);
- memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(memcg, NR_FILE_MAPPED);
- memcg_query.memcg_kmem = bpf_mem_cgroup_page_state(memcg, MEMCG_KMEM);
- memcg_query.pgfault = bpf_mem_cgroup_vm_events(memcg, PGFAULT);
+ idx = bpf_core_enum_value(enum node_stat_item, NR_ANON_MAPPED);
+ if (idx == 0)
+ goto out;
+ memcg_query.nr_anon_mapped = bpf_mem_cgroup_page_state(memcg, idx);
+ idx = bpf_core_enum_value(enum node_stat_item, NR_SHMEM);
+ if (idx == 0)
+ goto out;
+ memcg_query.nr_shmem = bpf_mem_cgroup_page_state(memcg, idx);
+
+ idx = bpf_core_enum_value(enum node_stat_item, NR_FILE_PAGES);
+ if (idx == 0)
+ goto out;
+ memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(memcg, idx);
+
+ idx = bpf_core_enum_value(enum node_stat_item, NR_FILE_MAPPED);
+ if (idx == 0)
+ goto out;
+ memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(memcg, idx);
+
+ idx = bpf_core_enum_value(enum memcg_stat_item, MEMCG_KMEM);
+ if (idx == 0)
+ goto out;
+ memcg_query.memcg_kmem = bpf_mem_cgroup_page_state(memcg, idx);
+
+ idx = bpf_core_enum_value(enum vm_event_item, PGFAULT);
+ if (idx == 0)
+ goto out;
+ memcg_query.pgfault = bpf_mem_cgroup_vm_events(memcg, idx);
+
+ ret = 0;
+out:
bpf_put_mem_cgroup(memcg);
- return 0;
+ return ret;
}
--
2.43.0On 2/12/26 11:23 PM, Hui Zhu wrote: > From: Hui Zhu <zhuhui@kylinos.cn> > > Replace hardcoded enum values with bpf_core_enum_value() calls in > cgroup_iter_memcg test to improve portability across different > kernel versions. > > The change adds runtime enum value resolution for: > - node_stat_item: NR_ANON_MAPPED, NR_SHMEM, NR_FILE_PAGES, > NR_FILE_MAPPED > - memcg_stat_item: MEMCG_KMEM > - vm_event_item: PGFAULT > > This ensures the BPF program can adapt to enum value changes > between kernel versions, returning early if any enum value is > unavailable (returns 0). > > Signed-off-by: Hui Zhu <zhuhui@kylinos.cn> > --- > .../selftests/bpf/progs/cgroup_iter_memcg.c | 41 +++++++++++++++---- > 1 file changed, 34 insertions(+), 7 deletions(-) > > diff --git a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c > index 59fb70a3cc50..b020951dd7e6 100644 > --- a/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c > +++ b/tools/testing/selftests/bpf/progs/cgroup_iter_memcg.c > @@ -15,6 +15,8 @@ int cgroup_memcg_query(struct bpf_iter__cgroup *ctx) > struct cgroup *cgrp = ctx->cgroup; > struct cgroup_subsys_state *css; > struct mem_cgroup *memcg; > + int ret = 1; > + int idx; > > if (!cgrp) > return 1; > @@ -26,14 +28,39 @@ int cgroup_memcg_query(struct bpf_iter__cgroup *ctx) > > bpf_mem_cgroup_flush_stats(memcg); > > - memcg_query.nr_anon_mapped = bpf_mem_cgroup_page_state(memcg, NR_ANON_MAPPED); > - memcg_query.nr_shmem = bpf_mem_cgroup_page_state(memcg, NR_SHMEM); > - memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(memcg, NR_FILE_PAGES); > - memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(memcg, NR_FILE_MAPPED); > - memcg_query.memcg_kmem = bpf_mem_cgroup_page_state(memcg, MEMCG_KMEM); > - memcg_query.pgfault = bpf_mem_cgroup_vm_events(memcg, PGFAULT); > + idx = bpf_core_enum_value(enum node_stat_item, NR_ANON_MAPPED); > + if (idx == 0) > + goto out; > + memcg_query.nr_anon_mapped = bpf_mem_cgroup_page_state(memcg, idx); > > + idx = bpf_core_enum_value(enum node_stat_item, NR_SHMEM); > + if (idx == 0) > + goto out; > + memcg_query.nr_shmem = bpf_mem_cgroup_page_state(memcg, idx); > + > + idx = bpf_core_enum_value(enum node_stat_item, NR_FILE_PAGES); > + if (idx == 0) > + goto out; > + memcg_query.nr_file_pages = bpf_mem_cgroup_page_state(memcg, idx); > + > + idx = bpf_core_enum_value(enum node_stat_item, NR_FILE_MAPPED); > + if (idx == 0) > + goto out; > + memcg_query.nr_file_mapped = bpf_mem_cgroup_page_state(memcg, idx); > + > + idx = bpf_core_enum_value(enum memcg_stat_item, MEMCG_KMEM); > + if (idx == 0) > + goto out; > + memcg_query.memcg_kmem = bpf_mem_cgroup_page_state(memcg, idx); > + > + idx = bpf_core_enum_value(enum vm_event_item, PGFAULT); > + if (idx == 0) > + goto out; This is getting messy. Most of these values should be on any system regardless of boot-params. I was expecting you would make the call inline. Let's simplify this whole series. This selftest only needs to exercise bpf_mem_cgroup_page_state() and bpf_mem_cgroup_vm_events(). I think we can remove the kmem subtest altogether and still have the coverage we need. You could then call bpf_core_enum_value() inline as an argument to the kfuncs above and not need to check if they exist (just let them give you the host-specific co-re value).
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