diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-09-29 18:03:33 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-30 14:17:10 +0100 |
| commit | acbd0c8144138b6e652240bba248910d330d71bf (patch) | |
| tree | c8834059bb0c4d98bf6446de0c7d2b8b59d377f6 /net/mptcp | |
| parent | 59f09ae8fac4a990070fc6bdc889d0e0118664ea (diff) | |
mptcp: use batch snmp operations in mptcp_seq_show()
Using snmp_get_cpu_field_batch() allows for better cpu cache
utilization, especially on hosts with large number of cpus.
Also remove special handling when mptcp mibs where not yet
allocated.
I chose to use temporary storage on the stack to keep this patch simple.
We might in the future use the storage allocated in netstat_seq_show().
Combined with prior patch (inlining snmp_get_cpu_field)
time to fetch and output mptcp counters on a 256 cpu host [1]
goes from 75 usec to 16 usec.
[1] L1 cache size is 32KB, it is not big enough to hold all dataset.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/mib.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/net/mptcp/mib.c b/net/mptcp/mib.c index b21ff9be04c6..3240b72271a7 100644 --- a/net/mptcp/mib.c +++ b/net/mptcp/mib.c @@ -72,6 +72,7 @@ bool mptcp_mib_alloc(struct net *net) void mptcp_seq_show(struct seq_file *seq) { + unsigned long sum[ARRAY_SIZE(mptcp_snmp_list) - 1]; struct net *net = seq->private; int i; @@ -81,17 +82,13 @@ void mptcp_seq_show(struct seq_file *seq) seq_puts(seq, "\nMPTcpExt:"); - if (!net->mib.mptcp_statistics) { - for (i = 0; mptcp_snmp_list[i].name; i++) - seq_puts(seq, " 0"); - - seq_putc(seq, '\n'); - return; - } + memset(sum, 0, sizeof(sum)); + if (net->mib.mptcp_statistics) + snmp_get_cpu_field_batch(sum, mptcp_snmp_list, + net->mib.mptcp_statistics); for (i = 0; mptcp_snmp_list[i].name; i++) - seq_printf(seq, " %lu", - snmp_fold_field(net->mib.mptcp_statistics, - mptcp_snmp_list[i].entry)); + seq_printf(seq, " %lu", sum[i]); + seq_putc(seq, '\n'); } |