sfc: The size of the RX recycle ring should be more flexible

Ideally the size would depend on the link speed, but the recycle
ring is created when the interface is brought up before the driver
knows the link speed. So size it for the maximum speed of a given NIC.
PowerPC is only supported on SFN7xxx and SFN8xxx NICs.

With this patch on a 40G NIC the number of calls to alloc_pages and
friends went down from about 18% to under 2%.
On a 10G NIC the number of calls to alloc_pages and friends went down
from about 15% to 0 (perf did not capture any calls during the 60
second test).
On a 100G NIC the number of calls to alloc_pages and friends went down
from about 23% to 4%.

Reported-by: Íñigo Huguet <ihuguet@redhat.com>
Signed-off-by: Martin Habets <habetsm.xilinx@gmail.com>
Link: https://lore.kernel.org/r/20220131111054.cp4f6foyinaarwbn@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index cf366ed2557cc54030a2de55e5fbc30072de977b..50d535981a35f02f90bfb58f2faf522176d49f90 100644 (file)
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -3990,6 +3990,30 @@ static unsigned int ef10_check_caps(const struct efx_nic *efx,
        }
 }
 
+static unsigned int efx_ef10_recycle_ring_size(const struct efx_nic *efx)
+{
+       unsigned int ret = EFX_RECYCLE_RING_SIZE_10G;
+
+       /* There is no difference between PFs and VFs. The side is based on
+        * the maximum link speed of a given NIC.
+        */
+       switch (efx->pci_dev->device & 0xfff) {
+       case 0x0903:    /* Farmingdale can do up to 10G */
+               break;
+       case 0x0923:    /* Greenport can do up to 40G */
+       case 0x0a03:    /* Medford can do up to 40G */
+               ret *= 4;
+               break;
+       default:        /* Medford2 can do up to 100G */
+               ret *= 10;
+       }
+
+       if (IS_ENABLED(CONFIG_PPC64))
+               ret *= 4;
+
+       return ret;
+}
+
 #define EF10_OFFLOAD_FEATURES          \
        (NETIF_F_IP_CSUM |              \
         NETIF_F_HW_VLAN_CTAG_FILTER |  \
@@ -4106,6 +4130,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = {
        .check_caps = ef10_check_caps,
        .print_additional_fwver = efx_ef10_print_additional_fwver,
        .sensor_event = efx_mcdi_sensor_event,
+       .rx_recycle_ring_size = efx_ef10_recycle_ring_size,
 };
 
 const struct efx_nic_type efx_hunt_a0_nic_type = {
@@ -4243,4 +4268,5 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
        .check_caps = ef10_check_caps,
        .print_additional_fwver = efx_ef10_print_additional_fwver,
        .sensor_event = efx_mcdi_sensor_event,
+       .rx_recycle_ring_size = efx_ef10_recycle_ring_size,
 };

diff --git a/drivers/net/ethernet/sfc/ef100_nic.c b/drivers/net/ethernet/sfc/ef100_nic.c
index f79b14a119ae45be0b22228430269360cbef7ca5..a07cbf45a3266649dce019ef64788d363c367176 100644 (file)
--- a/drivers/net/ethernet/sfc/ef100_nic.c
+++ b/drivers/net/ethernet/sfc/ef100_nic.c
@@ -23,6 +23,7 @@
 #include "ef100_rx.h"
 #include "ef100_tx.h"
 #include "ef100_netdev.h"
+#include "rx_common.h"
 
 #define EF100_MAX_VIS 4096
 #define EF100_NUM_MCDI_BUFFERS 1
@@ -696,6 +697,12 @@ static unsigned int ef100_check_caps(const struct efx_nic *efx,
        }
 }
 
+static unsigned int efx_ef100_recycle_ring_size(const struct efx_nic *efx)
+{
+       /* Maximum link speed for Riverhead is 100G */
+       return 10 * EFX_RECYCLE_RING_SIZE_10G;
+}
+
 /*     NIC level access functions
  */
 #define EF100_OFFLOAD_FEATURES (NETIF_F_HW_CSUM | NETIF_F_RXCSUM |     \
@@ -770,6 +777,7 @@ const struct efx_nic_type ef100_pf_nic_type = {
        .rx_push_rss_context_config = efx_mcdi_rx_push_rss_context_config,
        .rx_pull_rss_context_config = efx_mcdi_rx_pull_rss_context_config,
        .rx_restore_rss_contexts = efx_mcdi_rx_restore_rss_contexts,
+       .rx_recycle_ring_size = efx_ef100_recycle_ring_size,
 
        .reconfigure_mac = ef100_reconfigure_mac,
        .reconfigure_port = efx_mcdi_port_reconfigure,
@@ -849,6 +857,7 @@ const struct efx_nic_type ef100_vf_nic_type = {
        .rx_pull_rss_config = efx_mcdi_rx_pull_rss_config,
        .rx_push_rss_config = efx_mcdi_pf_rx_push_rss_config,
        .rx_restore_rss_contexts = efx_mcdi_rx_restore_rss_contexts,
+       .rx_recycle_ring_size = efx_ef100_recycle_ring_size,
 
        .reconfigure_mac = ef100_reconfigure_mac,
        .test_nvram = efx_new_mcdi_nvram_test_all,

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index cc15ee8812d9eb5f1d7bc7f46ab043d1615f3996..c75dc75e2857dee75e212a5df5d5b86ec62573bb 100644 (file)
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1282,6 +1282,7 @@ struct efx_udp_tunnel {
  * @udp_tnl_has_port: Check if a port has been added as UDP tunnel
  * @print_additional_fwver: Dump NIC-specific additional FW version info
  * @sensor_event: Handle a sensor event from MCDI
+ * @rx_recycle_ring_size: Size of the RX recycle ring
  * @revision: Hardware architecture revision
  * @txd_ptr_tbl_base: TX descriptor ring base address
  * @rxd_ptr_tbl_base: RX descriptor ring base address
@@ -1460,6 +1461,7 @@ struct efx_nic_type {
        size_t (*print_additional_fwver)(struct efx_nic *efx, char *buf,
                                         size_t len);
        void (*sensor_event)(struct efx_nic *efx, efx_qword_t *ev);
+       unsigned int (*rx_recycle_ring_size)(const struct efx_nic *efx);
 
        int revision;
        unsigned int txd_ptr_tbl_base;

diff --git a/drivers/net/ethernet/sfc/nic_common.h b/drivers/net/ethernet/sfc/nic_common.h
index b9cafe9cd568eefe33c7623a9475dae9b5451161..0cef35c0c559ac308b6d3d70847121f9e7486bbc 100644 (file)
--- a/drivers/net/ethernet/sfc/nic_common.h
+++ b/drivers/net/ethernet/sfc/nic_common.h
@@ -195,6 +195,11 @@ static inline void efx_sensor_event(struct efx_nic *efx, efx_qword_t *ev)
                efx->type->sensor_event(efx, ev);
 }
 
+static inline unsigned int efx_rx_recycle_ring_size(const struct efx_nic *efx)
+{
+       return efx->type->rx_recycle_ring_size(efx);
+}
+
 /* Some statistics are computed as A - B where A and B each increase
  * linearly with some hardware counter(s) and the counters are read
  * asynchronously.  If the counters contributing to B are always read

diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c
index 633ca77a26fd19133cb3b950884c364f7cab7b94..1b22c7be0088e74194e4a556d3ee2341aec4b5fd 100644 (file)
--- a/drivers/net/ethernet/sfc/rx_common.c
+++ b/drivers/net/ethernet/sfc/rx_common.c
@@ -23,13 +23,6 @@ module_param(rx_refill_threshold, uint, 0444);
 MODULE_PARM_DESC(rx_refill_threshold,
                 "RX descriptor ring refill threshold (%)");
 
-/* Number of RX buffers to recycle pages for.  When creating the RX page recycle
- * ring, this number is divided by the number of buffers per page to calculate
- * the number of pages to store in the RX page recycle ring.
- */
-#define EFX_RECYCLE_RING_SIZE_IOMMU 4096
-#define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
-
 /* RX maximum head room required.
  *
  * This must be at least 1 to prevent overflow, plus one packet-worth
@@ -141,16 +134,7 @@ static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
        unsigned int bufs_in_recycle_ring, page_ring_size;
        struct efx_nic *efx = rx_queue->efx;
 
-       /* Set the RX recycle ring size */
-#ifdef CONFIG_PPC64
-       bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
-#else
-       if (iommu_present(&pci_bus_type))
-               bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
-       else
-               bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
-#endif /* CONFIG_PPC64 */
-
+       bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
        page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
                                            efx->rx_bufs_per_page);
        rx_queue->page_ring = kcalloc(page_ring_size,

diff --git a/drivers/net/ethernet/sfc/rx_common.h b/drivers/net/ethernet/sfc/rx_common.h
index 207ccd8ba06219bc74b2c80a8807e9a84c2b1236..fbd2769307f915d08cf3c4a7fd53953f5dbffce3 100644 (file)
--- a/drivers/net/ethernet/sfc/rx_common.h
+++ b/drivers/net/ethernet/sfc/rx_common.h
@@ -18,6 +18,12 @@
 #define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
                                      EFX_RX_USR_BUF_SIZE)
 
+/* Number of RX buffers to recycle pages for.  When creating the RX page recycle
+ * ring, this number is divided by the number of buffers per page to calculate
+ * the number of pages to store in the RX page recycle ring.
+ */
+#define EFX_RECYCLE_RING_SIZE_10G      256
+
 static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
 {
        return page_address(buf->page) + buf->page_offset;

diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index 16347a6d0c47d050f529926817eb5399114ac44b..ce3060e15b54333a7eb3890893e4a73e7d38843c 100644 (file)
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -25,6 +25,7 @@
 #include "mcdi_port_common.h"
 #include "selftest.h"
 #include "siena_sriov.h"
+#include "rx_common.h"
 
 /* Hardware control for SFC9000 family including SFL9021 (aka Siena). */
 
@@ -958,6 +959,12 @@ static unsigned int siena_check_caps(const struct efx_nic *efx,
        return 0;
 }
 
+static unsigned int efx_siena_recycle_ring_size(const struct efx_nic *efx)
+{
+       /* Maximum link speed is 10G */
+       return EFX_RECYCLE_RING_SIZE_10G;
+}
+
 /**************************************************************************
  *
  * Revision-dependent attributes used by efx.c and nic.c
@@ -1098,4 +1105,5 @@ const struct efx_nic_type siena_a0_nic_type = {
        .rx_hash_key_size = 16,
        .check_caps = siena_check_caps,
        .sensor_event = efx_mcdi_sensor_event,
+       .rx_recycle_ring_size = efx_siena_recycle_ring_size,
 };