| Message ID | OS3P286MB2295FA2701BCE468E367607AF5D69@OS3P286MB2295.JPNP286.PROD.OUTLOOK.COM (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net-next,v3,1/1] net:openvswitch:reduce cpu_used_mask memory | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net-next |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Single patches do not need cover letters |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 0 this patch: 0 |
| netdev/cc_maintainers | success | CCed 7 of 7 maintainers |
| netdev/build_clang | success | Errors and warnings before: 0 this patch: 0 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 0 this patch: 0 |
| netdev/checkpatch | warning | WARNING: line length of 82 exceeds 80 columns |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
On 2 Feb 2023, at 11:32, 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 > as well as the iteration of bits in cpu_used_mask when handling > netlink message from ofproto I’m trying to understand how this will decrease memory usage. The size of the flow_cache stayed the same (actually it’s large due to the extra pointer). Also do not understand why the iteration is less, as the mask is initialized the same. Cheers, Eelco > To address this, redefine cpu_used_mask to pointer > append cpumask_size() bytes after 'stat' to hold cpumask > > cpumask 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 | 8 +++++--- > net/openvswitch/flow.h | 2 +- > net/openvswitch/flow_table.c | 8 +++++--- > 3 files changed, 11 insertions(+), 7 deletions(-) > > diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c > index e20d1a973417..0109a5f86f6a 100644 > --- a/net/openvswitch/flow.c > +++ b/net/openvswitch/flow.c > @@ -107,7 +107,7 @@ 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 +135,8 @@ 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 +160,8 @@ 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..dc6a174c3194 100644 > --- a/net/openvswitch/flow_table.c > +++ b/net/openvswitch/flow_table.c > @@ -87,11 +87,12 @@ struct sw_flow *ovs_flow_alloc(void) > if (!stats) > goto err; > > + flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids]; > spin_lock_init(&stats->lock); > > 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; > -- > 2.27.0 > > _______________________________________________ > dev mailing list > dev@openvswitch.org > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
On 2 Feb 2023, at 12:26, 陶 缘 wrote: > Hi, Eelco: > > Thanks for your time going through the detail. > The thing is: sizeof(struct cpumask), with default CONFIG_NR_CPUS 8192, has a size of 1024 bytes even on a system with only 4 cpus. > While in practice the cpumask APIs like cpumask_next and cpumask_set_cpu never access more than cpumask_size() of bytes in the bitmap > My change used cpumask_size() (in above example, consume 8 bytes after alignement for the cpumask, it saved 1016 bytes for every flow. I looked at the wrong nr_cpumask_bits definition, so thanks for this education :) > Your question reminded me to revisit the description "as well as the iteration of bits in cpu_used_mask", after a second think, this statement is not valid and should be removed. > since the iteration API will not access the number of bytes decided by nr_cpu_ids(running CPUs) > > I will remove this statement after solving a final style issue in the next submission. Thanks! > Thanks > eddy > ________________________________ > 发件人: Eelco Chaudron <echaudro@redhat.com> > 发送时间: 2023年2月2日 11:05 > 收件人: Eddy Tao <taoyuan_eddy@hotmail.com> > 抄送: netdev@vger.kernel.org <netdev@vger.kernel.org>; dev@openvswitch.org <dev@openvswitch.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; David S. Miller <davem@davemloft.net> > 主题: Re: [ovs-dev] [PATCH net-next v3 1/1] net:openvswitch:reduce cpu_used_mask memory > > > > On 2 Feb 2023, at 11:32, 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 >> as well as the iteration of bits in cpu_used_mask when handling >> netlink message from ofproto > > I’m trying to understand how this will decrease memory usage. The size of the flow_cache stayed the same (actually it’s large due to the extra pointer). > > Also do not understand why the iteration is less, as the mask is initialized the same. > > Cheers, > > Eelco > >> To address this, redefine cpu_used_mask to pointer >> append cpumask_size() bytes after 'stat' to hold cpumask >> >> cpumask 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 | 8 +++++--- >> net/openvswitch/flow.h | 2 +- >> net/openvswitch/flow_table.c | 8 +++++--- >> 3 files changed, 11 insertions(+), 7 deletions(-) >> >> diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c >> index e20d1a973417..0109a5f86f6a 100644 >> --- a/net/openvswitch/flow.c >> +++ b/net/openvswitch/flow.c >> @@ -107,7 +107,7 @@ 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 +135,8 @@ 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 +160,8 @@ 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..dc6a174c3194 100644 >> --- a/net/openvswitch/flow_table.c >> +++ b/net/openvswitch/flow_table.c >> @@ -87,11 +87,12 @@ struct sw_flow *ovs_flow_alloc(void) >> if (!stats) >> goto err; >> >> + flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids]; >> spin_lock_init(&stats->lock); >> >> 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; >> -- >> 2.27.0 >> >> _______________________________________________ >> dev mailing list >> dev@openvswitch.org >> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
On 2 Feb 2023, at 13:40, 陶 缘 wrote: > Hi, Eelco: > > I have a query regarding to the style check. > Though the './scripts/checkpatch.pl' emit no warning/error, the 'netdev/checkpatch' still has one warning "WARNING: line length of 82 exceeds 80 columns" > I went through the patch line by line and could not find any changed line exceeding the 80 character limit. > > I am afraid that the netdev/checkpatch takes counts on the removed line(old removed line has length exceeding 80 and i have revised that in the patch already > > Is there any known issue regarding to the netdev/checkpatch? Not sure which netdev/checkpatch you are referring to. I always you the general kernel one in /script/checkpatch.pl. Your patch looks good to me with /script/checkpatch.pl --strict. > Best regards > > eddy > > ________________________________ > 发件人: Eelco Chaudron <echaudro@redhat.com> > 发送时间: 2023年2月2日 11:44 > 收件人: 陶 缘 <taoyuan_eddy@hotmail.com> > 抄送: netdev@vger.kernel.org <netdev@vger.kernel.org>; dev@openvswitch.org <dev@openvswitch.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; David S. Miller <davem@davemloft.net> > 主题: Re: [ovs-dev] [PATCH net-next v3 1/1] net:openvswitch:reduce cpu_used_mask memory > > > > On 2 Feb 2023, at 12:26, 陶 缘 wrote: > >> Hi, Eelco: >> >> Thanks for your time going through the detail. >> The thing is: sizeof(struct cpumask), with default CONFIG_NR_CPUS 8192, has a size of 1024 bytes even on a system with only 4 cpus. >> While in practice the cpumask APIs like cpumask_next and cpumask_set_cpu never access more than cpumask_size() of bytes in the bitmap >> My change used cpumask_size() (in above example, consume 8 bytes after alignement for the cpumask, it saved 1016 bytes for every flow. > > I looked at the wrong nr_cpumask_bits definition, so thanks for this education :) > >> Your question reminded me to revisit the description "as well as the iteration of bits in cpu_used_mask", after a second think, this statement is not valid and should be removed. >> since the iteration API will not access the number of bytes decided by nr_cpu_ids(running CPUs) >> >> I will remove this statement after solving a final style issue in the next submission. > > Thanks! > > >> Thanks >> eddy >> ________________________________ >> 发件人: Eelco Chaudron <echaudro@redhat.com> >> 发送时间: 2023年2月2日 11:05 >> 收件人: Eddy Tao <taoyuan_eddy@hotmail.com> >> 抄送: netdev@vger.kernel.org <netdev@vger.kernel.org>; dev@openvswitch.org <dev@openvswitch.org>; linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Eric Dumazet <edumazet@google.com>; Jakub Kicinski <kuba@kernel.org>; Paolo Abeni <pabeni@redhat.com>; David S. Miller <davem@davemloft.net> >> 主题: Re: [ovs-dev] [PATCH net-next v3 1/1] net:openvswitch:reduce cpu_used_mask memory >> >> >> >> On 2 Feb 2023, at 11:32, 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 >>> as well as the iteration of bits in cpu_used_mask when handling >>> netlink message from ofproto >> >> I’m trying to understand how this will decrease memory usage. The size of the flow_cache stayed the same (actually it’s large due to the extra pointer). >> >> Also do not understand why the iteration is less, as the mask is initialized the same. >> >> Cheers, >> >> Eelco >> >>> To address this, redefine cpu_used_mask to pointer >>> append cpumask_size() bytes after 'stat' to hold cpumask >>> >>> cpumask 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 | 8 +++++--- >>> net/openvswitch/flow.h | 2 +- >>> net/openvswitch/flow_table.c | 8 +++++--- >>> 3 files changed, 11 insertions(+), 7 deletions(-) >>> >>> diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c >>> index e20d1a973417..0109a5f86f6a 100644 >>> --- a/net/openvswitch/flow.c >>> +++ b/net/openvswitch/flow.c >>> @@ -107,7 +107,7 @@ 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 +135,8 @@ 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 +160,8 @@ 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..dc6a174c3194 100644 >>> --- a/net/openvswitch/flow_table.c >>> +++ b/net/openvswitch/flow_table.c >>> @@ -87,11 +87,12 @@ struct sw_flow *ovs_flow_alloc(void) >>> if (!stats) >>> goto err; >>> >>> + flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids]; >>> spin_lock_init(&stats->lock); >>> >>> 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; >>> -- >>> 2.27.0 >>> >>> _______________________________________________ >>> dev mailing list >>> dev@openvswitch.org >>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index e20d1a973417..0109a5f86f6a 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -107,7 +107,7 @@ 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 +135,8 @@ 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 +160,8 @@ 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..dc6a174c3194 100644 --- a/net/openvswitch/flow_table.c +++ b/net/openvswitch/flow_table.c @@ -87,11 +87,12 @@ struct sw_flow *ovs_flow_alloc(void) if (!stats) goto err; + flow->cpu_used_mask = (struct cpumask *)&flow->stats[nr_cpu_ids]; spin_lock_init(&stats->lock); 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 as well as the iteration of bits in cpu_used_mask when handling netlink message from ofproto To address this, redefine cpu_used_mask to pointer append cpumask_size() bytes after 'stat' to hold cpumask cpumask 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 | 8 +++++--- net/openvswitch/flow.h | 2 +- net/openvswitch/flow_table.c | 8 +++++--- 3 files changed, 11 insertions(+), 7 deletions(-)