From: Jacob Keller <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit 27d9ce4fd0e2e75c2907f6d3dc0487012a3e4298 upstream. ixgbe_napi_disable_all calls napi_disable on each queue, however the busy polling code introduced a local_bh_disable()d context around the napi_disable. The original author did not realize that napi_disable might sleep, which would cause a sleep while atomic BUG. In addition, on a single processor system, the ixgbe_qv_lock_napi loop shouldn't have to mdelay. This patch adds an ixgbe_qv_disable along with a new IXGBE_QV_STATE_DISABLED bit, which it uses to indicate to the poll and napi routines that the q_vector has been disabled. Now the ixgbe_napi_disable_all function will wait until all pending work has been finished and prevent any future work from being started. Signed-off-by: Jacob Keller <[email protected]> Cc: Eliezer Tamir <[email protected]> Cc: Alexander Duyck <[email protected]> Cc: Hyong-Youb Kim <[email protected]> Cc: Amir Vadai <[email protected]> Cc: Dmitry Kravkov <[email protected]> Tested-by: Phil Schmitt <[email protected]> Signed-off-by: Jeff Kirsher <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- drivers/net/ethernet/intel/ixgbe/ixgbe.h | 48 ++++++++++++++++++++------- drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 6 ++-- 2 files changed, 38 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h index 0ac6b11c6e4e..4506f8a15c8a 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h @@ -369,11 +369,13 @@ struct ixgbe_q_vector { #ifdef CONFIG_NET_RX_BUSY_POLL unsigned int state; #define IXGBE_QV_STATE_IDLE 0 -#define IXGBE_QV_STATE_NAPI 1 /* NAPI owns this QV */ -#define IXGBE_QV_STATE_POLL 2 /* poll owns this QV */ -#define IXGBE_QV_LOCKED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL) -#define IXGBE_QV_STATE_NAPI_YIELD 4 /* NAPI yielded this QV */ -#define IXGBE_QV_STATE_POLL_YIELD 8 /* poll yielded this QV */ +#define IXGBE_QV_STATE_NAPI 1 /* NAPI owns this QV */ +#define IXGBE_QV_STATE_POLL 2 /* poll owns this QV */ +#define IXGBE_QV_STATE_DISABLED 4 /* QV is disabled */ +#define IXGBE_QV_OWNED (IXGBE_QV_STATE_NAPI | IXGBE_QV_STATE_POLL) +#define IXGBE_QV_LOCKED (IXGBE_QV_OWNED | IXGBE_QV_STATE_DISABLED) +#define IXGBE_QV_STATE_NAPI_YIELD 8 /* NAPI yielded this QV */ +#define IXGBE_QV_STATE_POLL_YIELD 16 /* poll yielded this QV */ #define IXGBE_QV_YIELD (IXGBE_QV_STATE_NAPI_YIELD | IXGBE_QV_STATE_POLL_YIELD) #define IXGBE_QV_USER_PEND (IXGBE_QV_STATE_POLL | IXGBE_QV_STATE_POLL_YIELD) spinlock_t lock; @@ -394,7 +396,7 @@ static inline void ixgbe_qv_init_lock(struct ixgbe_q_vector *q_vector) static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) { int rc = true; - spin_lock(&q_vector->lock); + spin_lock_bh(&q_vector->lock); if (q_vector->state & IXGBE_QV_LOCKED) { WARN_ON(q_vector->state & IXGBE_QV_STATE_NAPI); q_vector->state |= IXGBE_QV_STATE_NAPI_YIELD; @@ -405,7 +407,7 @@ static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) } else /* we don't care if someone yielded */ q_vector->state = IXGBE_QV_STATE_NAPI; - spin_unlock(&q_vector->lock); + spin_unlock_bh(&q_vector->lock); return rc; } @@ -413,14 +415,15 @@ static inline bool ixgbe_qv_lock_napi(struct ixgbe_q_vector *q_vector) static inline bool ixgbe_qv_unlock_napi(struct ixgbe_q_vector *q_vector) { int rc = false; - spin_lock(&q_vector->lock); + spin_lock_bh(&q_vector->lock); WARN_ON(q_vector->state & (IXGBE_QV_STATE_POLL | IXGBE_QV_STATE_NAPI_YIELD)); if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD) rc = true; - q_vector->state = IXGBE_QV_STATE_IDLE; - spin_unlock(&q_vector->lock); + /* will reset state to idle, unless QV is disabled */ + q_vector->state &= IXGBE_QV_STATE_DISABLED; + spin_unlock_bh(&q_vector->lock); return rc; } @@ -451,7 +454,8 @@ static inline bool ixgbe_qv_unlock_poll(struct ixgbe_q_vector *q_vector) if (q_vector->state & IXGBE_QV_STATE_POLL_YIELD) rc = true; - q_vector->state = IXGBE_QV_STATE_IDLE; + /* will reset state to idle, unless QV is disabled */ + q_vector->state &= IXGBE_QV_STATE_DISABLED; spin_unlock_bh(&q_vector->lock); return rc; } @@ -459,9 +463,23 @@ static inline bool ixgbe_qv_unlock_poll(struct ixgbe_q_vector *q_vector) /* true if a socket is polling, even if it did not get the lock */ static inline bool ixgbe_qv_ll_polling(struct ixgbe_q_vector *q_vector) { - WARN_ON(!(q_vector->state & IXGBE_QV_LOCKED)); + WARN_ON(!(q_vector->state & IXGBE_QV_OWNED)); return q_vector->state & IXGBE_QV_USER_PEND; } + +/* false if QV is currently owned */ +static inline bool ixgbe_qv_disable(struct ixgbe_q_vector *q_vector) +{ + int rc = true; + spin_lock_bh(&q_vector->lock); + if (q_vector->state & IXGBE_QV_OWNED) + rc = false; + q_vector->state |= IXGBE_QV_STATE_DISABLED; + spin_unlock_bh(&q_vector->lock); + + return rc; +} + #else /* CONFIG_NET_RX_BUSY_POLL */ static inline void ixgbe_qv_init_lock(struct ixgbe_q_vector *q_vector) { @@ -491,6 +509,12 @@ static inline bool ixgbe_qv_ll_polling(struct ixgbe_q_vector *q_vector) { return false; } + +static inline bool ixgbe_qv_disable(struct ixgbe_q_vector *q_vector) +{ + return true; +} + #endif /* CONFIG_NET_RX_BUSY_POLL */ #ifdef CONFIG_IXGBE_HWMON diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index bf046e14ceb5..a178a9caa763 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -3893,15 +3893,13 @@ static void ixgbe_napi_disable_all(struct ixgbe_adapter *adapter) { int q_idx; - local_bh_disable(); /* for ixgbe_qv_lock_napi() */ for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) { napi_disable(&adapter->q_vector[q_idx]->napi); - while (!ixgbe_qv_lock_napi(adapter->q_vector[q_idx])) { + while (!ixgbe_qv_disable(adapter->q_vector[q_idx])) { pr_info("QV %d locked\n", q_idx); - mdelay(1); + usleep_range(1000, 20000); } } - local_bh_enable(); } #ifdef CONFIG_IXGBE_DCB -- 2.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
