[dpdk-dev] [PATCH 24/53] net/sfc/base: more accurately calculate number of PS credits

Andrew Rybchenko arybchenko at solarflare.com
Thu Nov 16 09:04:12 CET 2017


From: Andrew Rybchenko <Andrew.Rybchenko at oktetlabs.ru>

Maximum number of packets per 64k buffer should be rounded up
when calculating number of credits by event queue size.

Signed-off-by: Andrew Rybchenko <arybchenko at solarflare.com>
---
 drivers/net/sfc/base/ef10_ev.c | 2 +-
 drivers/net/sfc/base/efx.h     | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/sfc/base/ef10_ev.c b/drivers/net/sfc/base/ef10_ev.c
index 946efeb..2c6edf3 100644
--- a/drivers/net/sfc/base/ef10_ev.c
+++ b/drivers/net/sfc/base/ef10_ev.c
@@ -1370,7 +1370,7 @@ ef10_ev_rxlabel_init(
 	eersp->eers_rx_packed_stream = packed_stream;
 	if (packed_stream) {
 		eersp->eers_rx_packed_stream_credits = (eep->ee_mask + 1) /
-		    (EFX_RX_PACKED_STREAM_MEM_PER_CREDIT /
+		    EFX_DIV_ROUND_UP(EFX_RX_PACKED_STREAM_MEM_PER_CREDIT,
 		    EFX_RX_PACKED_STREAM_MIN_PACKET_SPACE);
 		EFSYS_ASSERT3U(eersp->eers_rx_packed_stream_credits, !=, 0);
 		/*
diff --git a/drivers/net/sfc/base/efx.h b/drivers/net/sfc/base/efx.h
index bf17aba..d7ce0b5 100644
--- a/drivers/net/sfc/base/efx.h
+++ b/drivers/net/sfc/base/efx.h
@@ -48,6 +48,9 @@ extern "C" {
 #define	EFX_FIELD_OFFSET(_type, _field)		\
 	((size_t) &(((_type *)0)->_field))
 
+/* The macro expands divider twice */
+#define	EFX_DIV_ROUND_UP(_n, _d)		(((_n) + (_d) - 1) / (_d))
+
 /* Return codes */
 
 typedef __success(return == 0) int efx_rc_t;
-- 
2.7.4



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