diff options
| author |   Dave Barach <dave@barachs.net> | 2018-01-19 13:09:20 -0500 |
|---|---|---|
| committer |   Florin Coras <florin.coras@gmail.com> | 2018-01-19 22:15:52 +0000 |
| commit | d47c509af13ddcb80f82aebd25dc4f40cc778a0e (patch) | |
| tree | c5983c129c95682b4f9206019cec6a5024852c1d | |
| parent | ba7992aa62523d014b55802463fb3357c7099b70 (diff) | |
Fix MP hazard in interrupt node scheduling
Change-Id: Iff14ed6ffd822eb2286aac6af467d9c8660e3d81
Signed-off-by: Dave Barach <dave@barachs.net>
| -rw-r--r-- | src/vlib/main.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/src/vlib/main.c b/src/vlib/main.c index d32ca7b8ea2..f915aa41b3b 100644 --- a/src/vlib/main.c +++ b/src/vlib/main.c @@ -1514,13 +1514,19 @@ vlib_main_or_worker_loop (vlib_main_t * vm, int is_main) /* Next handle interrupts. */ { + /* unlocked read, for performance */ uword l = _vec_len (nm->pending_interrupt_node_runtime_indices); uword i; - if (l > 0) + if (PREDICT_FALSE (l > 0)) { u32 *tmp; if (!is_main) - clib_spinlock_lock (&nm->pending_interrupt_lock); + { + clib_spinlock_lock (&nm->pending_interrupt_lock); + /* Re-read w/ lock held, in case another thread added an item */ + l = _vec_len (nm->pending_interrupt_node_runtime_indices); + } + tmp = nm->pending_interrupt_node_runtime_indices; nm->pending_interrupt_node_runtime_indices = last_node_runtime_indices; |