[PATCH v2 1/2] irqchip/gic-v4.1: Reduce the delay time of the poll on the GICR_VPENDBASER.Dirty bit

From: Shenming Lu
Date: Sat Nov 28 2020 - 12:59:19 EST


The 10 delay_us of the poll on the GICR_VPENDBASER.Dirty bit is too
high, which might greatly affect the total scheduling latency of a
vCPU in our measurement. So we reduce it to 1 to lessen the impact.

Signed-off-by: Shenming Lu <lushenming@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0fec31931e11..22f427135c6b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3809,7 +3809,7 @@ static void its_wait_vpt_parse_complete(void)
WARN_ON_ONCE(readq_relaxed_poll_timeout_atomic(vlpi_base + GICR_VPENDBASER,
val,
!(val & GICR_VPENDBASER_Dirty),
- 10, 500));
+ 1, 500));
}

static void its_vpe_schedule(struct its_vpe *vpe)
--
2.23.0