[PATCH net-next v7 1/9] ptr_ring: move free-space check into separate helper
From: Simon Schippers <hidden>
Date: 2026-01-07 21:06:14
Also in:
kvm, lkml, virtualization
Subsystem:
the rest · Maintainer:
Linus Torvalds
This patch moves the check for available free space for a new entry into a separate function. As a result, __ptr_ring_produce() remains logically unchanged, while the new helper allows callers to determine in advance whether subsequent __ptr_ring_produce() calls will succeed. This information can, for example, be used to temporarily stop producing until __ptr_ring_peek() indicates that space is available again. Co-developed-by: Tim Gebauer <redacted> Signed-off-by: Tim Gebauer <redacted> Signed-off-by: Simon Schippers <redacted> --- include/linux/ptr_ring.h | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index 534531807d95..a5a3fa4916d3 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h@@ -96,6 +96,14 @@ static inline bool ptr_ring_full_bh(struct ptr_ring *r) return ret; } +static inline int __ptr_ring_produce_peek(struct ptr_ring *r) +{ + if (unlikely(!r->size) || r->queue[r->producer]) + return -ENOSPC; + + return 0; +} + /* Note: callers invoking this in a loop must use a compiler barrier, * for example cpu_relax(). Callers must hold producer_lock. * Callers are responsible for making sure pointer that is being queued
@@ -103,8 +111,10 @@ static inline bool ptr_ring_full_bh(struct ptr_ring *r) */ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { - if (unlikely(!r->size) || r->queue[r->producer]) - return -ENOSPC; + int p = __ptr_ring_produce_peek(r); + + if (p) + return p; /* Make sure the pointer we are storing points to a valid data. */ /* Pairs with the dependency ordering in __ptr_ring_consume. */
--
2.43.0