diff options
| author | Jake Hillion <jake@hillion.co.uk> | 2025-03-25 22:41:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-20 10:18:27 +0200 |
| commit | f2a2155d95556da602fe1857fdf39350de65e6a5 (patch) | |
| tree | 9960f40642441ae063191bdd54bd65803abef483 | |
| parent | 6fdf0854c358414bec1ce03cbf34f47cc3f8d32a (diff) | |
sched_ext: create_dsq: Return -EEXIST on duplicate request
commit a8897ed8523d4c9d782e282b18005a3779c92714 upstream.
create_dsq and therefore the scx_bpf_create_dsq kfunc currently silently
ignore duplicate entries. As a sched_ext scheduler is creating each DSQ
for a different purpose this is surprising behaviour.
Replace rhashtable_insert_fast which ignores duplicates with
rhashtable_lookup_insert_fast that reports duplicates (though doesn't
return their value). The rest of the code is structured correctly and
this now returns -EEXIST.
Tested by adding an extra scx_bpf_create_dsq to scx_simple. Previously
this was ignored, now init fails with a -17 code. Also ran scx_lavd
which continued to work well.
Signed-off-by: Jake Hillion <jake@hillion.co.uk>
Acked-by: Andrea Righi <arighi@nvidia.com>
Fixes: f0e1a0643a59 ("sched_ext: Implement BPF extensible scheduler class")
Cc: stable@vger.kernel.org # v6.12+
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/sched/ext.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index b08d8691b26b..85e4c05fec67 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -4501,8 +4501,8 @@ static struct scx_dispatch_q *create_dsq(u64 dsq_id, int node) init_dsq(dsq, dsq_id); - ret = rhashtable_insert_fast(&dsq_hash, &dsq->hash_node, - dsq_hash_params); + ret = rhashtable_lookup_insert_fast(&dsq_hash, &dsq->hash_node, + dsq_hash_params); if (ret) { kfree(dsq); return ERR_PTR(ret); |