[PATCH net-next 3/6] net/smc: Introduce a sysctl for setting SMC-R buffer type

Wen Gu
2022-07-12T11:51:50Z

This patch introduces the sysctl smcr_buf_type for setting
the type of SMC-R sndbufs and RMBs.

Valid values includes:

- SMCR_PHYS_CONT_BUFS, which means use physically contiguous
buffers for better performance and is the default value.

- SMCR_VIRT_CONT_BUFS, which means use virtually contiguous
buffers in case of physically contiguous memory is scarce.

- SMCR_MIXED_BUFS, which means first try to use physically
contiguous buffers. If not available, then use virtually
contiguous buffers.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
include/net/netns/smc.h | 1 +
net/smc/smc_core.h | 6 ++++++
net/smc/smc_sysctl.c | 11 +++++++++++
3 files changed, 18 insertions(+)

diff --git a/include/net/netns/smc.h b/include/net/netns/smc.h
index e5389ee..2adbe2b 100644
--- a/include/net/netns/smc.h
+++ b/include/net/netns/smc.h
@@ -18,5 +18,6 @@ struct netns_smc {
struct ctl_table_header *smc_hdr;
#endif
unsigned int sysctl_autocorking_size;
+ unsigned int sysctl_smcr_buf_type;
};
#endif
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 46ddec5..7652dfa 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -217,6 +217,12 @@ enum smc_lgr_type { /* redundancy state of lgr */
SMC_LGR_ASYMMETRIC_LOCAL, /* local has 1, peer 2 active RNICs */
};

+enum smcr_buf_type { /* types of SMC-R sndbufs and RMBs */
+ SMCR_PHYS_CONT_BUFS = 0,
+ SMCR_VIRT_CONT_BUFS = 1,
+ SMCR_MIXED_BUFS = 2,
+};
+
enum smc_llc_flowtype {
SMC_LLC_FLOW_NONE = 0,
SMC_LLC_FLOW_ADD_LINK = 2,
diff --git a/net/smc/smc_sysctl.c b/net/smc/smc_sysctl.c
index cf3ab13..0613868 100644
--- a/net/smc/smc_sysctl.c
+++ b/net/smc/smc_sysctl.c
@@ -15,6 +15,7 @@
#include <net/net_namespace.h>

#include "smc.h"
+#include "smc_core.h"
#include "smc_sysctl.h"

static struct ctl_table smc_table[] = {
@@ -25,6 +26,15 @@
.mode = 0644,
.proc_handler = proc_douintvec,
},
+ {
+ .procname = "smcr_buf_type",
+ .data = &init_net.smc.sysctl_smcr_buf_type,
+ .maxlen = sizeof(unsigned int),
+ .mode = 0644,
+ .proc_handler = proc_douintvec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_TWO,
+ },
{ }
};

@@ -49,6 +59,7 @@ int __net_init smc_sysctl_net_init(struct net *net)
goto err_reg;

net->smc.sysctl_autocorking_size = SMC_AUTOCORKING_DEFAULT_SIZE;
+ net->smc.sysctl_smcr_buf_type = SMCR_PHYS_CONT_BUFS;

return 0;

--
1.8.3.1