| Message ID | OS3P286MB22957550350801F37FB56DFFF5D79@OS3P286MB2295.JPNP286.PROD.OUTLOOK.COM (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v7,1/1] net:openvswitch:reduce cpu_used_mask memory | expand |
On Fri, Feb 03, 2023 at 11:42:45PM +0800, Eddy Tao wrote: > Use actual CPU number instead of hardcoded value to decide the size > of 'cpu_used_mask' in 'struct sw_flow'. Below is the reason. > > 'struct cpumask cpu_used_mask' is embedded in struct sw_flow. > Its size is hardcoded to CONFIG_NR_CPUS bits, which can be > 8192 by default, it costs memory and slows down ovs_flow_alloc > > To address this: > Redefine cpu_used_mask to pointer. > Append cpumask_size() bytes after 'stat' to hold cpumask. > Initialization cpu_used_mask right after stats_last_writer. > > APIs like cpumask_next and cpumask_set_cpu never access bits > beyond cpu count, cpumask_size() bytes of memory is enough > > Signed-off-by: Eddy Tao <taoyuan_eddy@hotmail.com> nit: I think the correct prefix for the patch subject is 'openvswitch:' And there should be a space after the prefix. [PATCH net-next v8 1/1] openvswitch: reduce cpu_used_mask
Hi, Simon: Thank you for the time on the review. and i looked into net folder and get various results 'net:', 'net: gre:', 'net: bridge:', 'net: thunderx', 'net: sock', 'net: genetlink', and there is also examples as you suggested like 'devlink:' similarly, in other folders i see similar inconsistency, mm folder is an example. I turned below links and did not find item regarding to the prefix definition Link: https://docs.kernel.org/process/maintainer-netdev.html Link: https://docs.kernel.org/process/submitting-patches.html#submittingpatches Going through the git log in file net/openvswitch/flow.c, the 'net: openvswitch: ' prefix were used in previous commits. I think the fix contained 'net' keep the prefix from name collision and better keeps it consistent with its neighbors in the same file And yes, there should be a blank space after the colon, i miss it, will update the revision, after we nail down the wording of the prefix. Thanks eddy On 2023/2/4 21:28, Simon Horman wrote: > nit: I think the correct prefix for the patch subject is 'openvswitch:' > And there should be a space after the prefix. > > [PATCH net-next v8 1/1] openvswitch: reduce cpu_used_mask
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index e20d1a973417..416976f70322 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -107,7 +107,8 @@ void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags, rcu_assign_pointer(flow->stats[cpu], new_stats); - cpumask_set_cpu(cpu, &flow->cpu_used_mask); + cpumask_set_cpu(cpu, + flow->cpu_used_mask); goto unlock; } } @@ -135,7 +136,8 @@ void ovs_flow_stats_get(const struct sw_flow *flow, memset(ovs_stats, 0, sizeof(*ovs_stats)); /* We open code this to make sure cpu 0 is always considered */ - for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) { + for (cpu = 0; cpu < nr_cpu_ids; + cpu = cpumask_next(cpu, flow->cpu_used_mask)) { struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]); if (stats) { @@ -159,7 +161,8 @@ void ovs_flow_stats_clear(struct sw_flow *flow) int cpu; /* We open code this to make sure cpu 0 is always considered */ - for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) { + for (cpu = 0; cpu < nr_cpu_ids; + cpu = cpumask_next(cpu, flow->cpu_used_mask)) { struct sw_flow_stats *stats = ovsl_dereference(flow->stats[cpu]); if (stats) { diff --git a/net/openvswitch/flow.h b/net/openvswitch/flow.h index 073ab73ffeaa..b5711aff6e76 100644 --- a/net/openvswitch/flow.h +++ b/net/openvswitch/flow.h @@ -229,7 +229,7 @@ struct sw_flow { */ struct sw_flow_key key; struct sw_flow_id id; - struct cpumask cpu_used_mask; + struct cpumask *cpu_used_mask; struct sw_flow_mask *mask; struct sw_flow_actions __rcu *sf_acts; struct sw_flow_stats __rcu *stats[]; /* One for each CPU. First one diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c index 0a0e4c283f02..791504b7f42b 100644 --- a/net/openvswitch/flow_table.c +++ b/net/openvswitch/flow_table.c @@ -79,6 +79,7 @@ struct sw_flow *ovs_flow_alloc(void) return ERR_PTR(-ENOMEM); flow->stats_last_writer = -1; + flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids]; /* Initialize the default stat node. */ stats = kmem_cache_alloc_node(flow_stats_cache, @@ -91,7 +92,7 @@ struct sw_flow *ovs_flow_alloc(void) RCU_INIT_POINTER(flow->stats[0], stats); - cpumask_set_cpu(0, &flow->cpu_used_mask); + cpumask_set_cpu(0, flow->cpu_used_mask); return flow; err: @@ -115,7 +116,7 @@ static void flow_free(struct sw_flow *flow) flow->sf_acts); /* We open code this to make sure cpu 0 is always considered */ for (cpu = 0; cpu < nr_cpu_ids; - cpu = cpumask_next(cpu, &flow->cpu_used_mask)) { + cpu = cpumask_next(cpu, flow->cpu_used_mask)) { if (flow->stats[cpu]) kmem_cache_free(flow_stats_cache, (struct sw_flow_stats __force *)flow->stats[cpu]); @@ -1196,7 +1197,8 @@ int ovs_flow_init(void) flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow) + (nr_cpu_ids - * sizeof(struct sw_flow_stats *)), + * sizeof(struct sw_flow_stats *)) + + cpumask_size(), 0, 0, NULL); if (flow_cache == NULL) return -ENOMEM;
Use actual CPU number instead of hardcoded value to decide the size of 'cpu_used_mask' in 'struct sw_flow'. Below is the reason. 'struct cpumask cpu_used_mask' is embedded in struct sw_flow. Its size is hardcoded to CONFIG_NR_CPUS bits, which can be 8192 by default, it costs memory and slows down ovs_flow_alloc To address this: Redefine cpu_used_mask to pointer. Append cpumask_size() bytes after 'stat' to hold cpumask. Initialization cpu_used_mask right after stats_last_writer. APIs like cpumask_next and cpumask_set_cpu never access bits beyond cpu count, cpumask_size() bytes of memory is enough Signed-off-by: Eddy Tao <taoyuan_eddy@hotmail.com> --- net/openvswitch/flow.c | 9 ++++++--- net/openvswitch/flow.h | 2 +- net/openvswitch/flow_table.c | 8 +++++--- 3 files changed, 12 insertions(+), 7 deletions(-)