Messages in this thread | | | From | Vlad Buslov <> | Subject | Re: [PATCH net-next 1/3] net: sched: cls_api: add skip_sw counter | Date | Fri, 16 Feb 2024 10:35:40 +0200 |
| |
On Thu 15 Feb 2024 at 23:34, Asbjørn Sloth Tønnesen <ast@fiberby.net> wrote: > Hi Jamal, > > Thank you for the review. > > On 2/15/24 17:39, Jamal Hadi Salim wrote: >> +Cc Vlad and Marcelo.. >> On Thu, Feb 15, 2024 at 11:06 AM Asbjørn Sloth Tønnesen <ast@fiberby.net> >> wrote: >>> >>> Maintain a count of skip_sw filters. >>> >>> This counter is protected by the cb_lock, and is updated >>> at the same time as offloadcnt. >>> >>> Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net> >>> --- >>> include/net/sch_generic.h | 1 + >>> net/sched/cls_api.c | 4 ++++ >>> 2 files changed, 5 insertions(+) >>> >>> diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h >>> index 934fdb977551..46a63d1818a0 100644 >>> --- a/include/net/sch_generic.h >>> +++ b/include/net/sch_generic.h >>> @@ -476,6 +476,7 @@ struct tcf_block { >>> struct flow_block flow_block; >>> struct list_head owner_list; >>> bool keep_dst; >>> + atomic_t skipswcnt; /* Number of skip_sw filters */ >>> atomic_t offloadcnt; /* Number of oddloaded filters */ >> For your use case is skipswcnt ever going to be any different than offloadcnt? > > No, we only use skip_sw filters, since we only use TC as a control path to > install skip_sw rules into hardware. > > AFAICT offloadcnt is the sum of skip_sw filters, and filters with no flags which > have implicitly been offloaded. > > The reason that I didn't just use offloadcnt, is that I'm not sure if it is > acceptable to treat implicitly offloaded rules without skip_sw, as if they were > explicitly skip_sw. It sounds reasonable, given that the filters without skip_* flags > shouldn't really care.
It is not acceptable since there are valid use-cases where packets need to match sw filters that are supposedly also in-hw. For example, filters with tunnel_key set action during neighbor update event.
> > I tried to only trigger the TC bypass, in the cases that I was absolutely sure would > be safe as a first step. > > >> cheers, >> jamal >> >>> unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */ >>> unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */ >>> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c >>> index ca5676b2668e..397c3d29659c 100644 >>> --- a/net/sched/cls_api.c >>> +++ b/net/sched/cls_api.c >>> @@ -3483,6 +3483,8 @@ static void tcf_block_offload_inc(struct tcf_block *block, u32 *flags) >>> if (*flags & TCA_CLS_FLAGS_IN_HW) >>> return; >>> *flags |= TCA_CLS_FLAGS_IN_HW; >>> + if (tc_skip_sw(*flags)) >>> + atomic_inc(&block->skipswcnt); >>> atomic_inc(&block->offloadcnt); >>> } >>> >>> @@ -3491,6 +3493,8 @@ static void tcf_block_offload_dec(struct tcf_block *block, u32 *flags) >>> if (!(*flags & TCA_CLS_FLAGS_IN_HW)) >>> return; >>> *flags &= ~TCA_CLS_FLAGS_IN_HW; >>> + if (tc_skip_sw(*flags)) >>> + atomic_dec(&block->skipswcnt); >>> atomic_dec(&block->offloadcnt); >>> } >>> >>> -- >>> 2.43.0 >>>
| |