On Sat, Dec 25, 2021 at 3:26 AM Cong Wang [off-list ref] wrote:

On Tue, Dec 21, 2021 at 5:24 PM Tonghao Zhang [off-list ref] wrote:

quoted

On Tue, Dec 21, 2021 at 1:57 AM Cong Wang [off-list ref] wrote:

quoted

On Mon, Dec 20, 2021 at 4:39 AM [off-list ref] wrote:

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From: Tonghao Zhang <redacted>

This patch allows user to select queue_mapping, range
from A to B. And user can use skbhash, cgroup classid
and cpuid to select Tx queues. Then we can load balance
packets from A to B queue. The range is an unsigned 16bit
value in decimal format.

$ tc filter ... action skbedit queue_mapping skbhash A B

"skbedit queue_mapping QUEUE_MAPPING" (from "man 8 tc-skbedit")
is enhanced with flags:
* SKBEDIT_F_TXQ_SKBHASH
* SKBEDIT_F_TXQ_CLASSID
* SKBEDIT_F_TXQ_CPUID

Once again, you are enforcing policies in kernel, which is not good.
Kernel should just set whatever you give to it, not selecting policies
like a menu.

I agree that, but for tc/net-sched layer, there are a lot of

If you agree, why still move on with this patch? Apparently
you don't. ;)

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networking policies, for example , cls_A, act_B, sch_C.

You are justifying your logic by shifting the topics here.

Hi Cong,
I mean that if the "policies" are networking policies, I don't agree
with you, because
the TC(or net sched layer), are networking policies, right ? and this
patch enhances the original feature of TC.

The qdisc algorithm is very different from your case, it is essentially
hard, if not impossible, to completely move to user-space. Even if we
had eBPF based Qdisc, its programmablility is still very limited.
Your code is much much much easier, which is essentially one-line,
hence you have to reason to compare it with this, nor you can even
justify it.

I think we have talked about this in another thread. And other
maintainers comment on this.

quoted

quoted

Any reason why you can't obtain these values in user-space?

Did you mean that we add this flags to iproute2 tools? This patch for
iproute2, is not post. If the kerenl patches are accepted, I will send
them.

Nope, I mean you can for example, obtain the CPU ID in user-space
and pass it directly to _current_ act_skbedit as it is.

This flag is passed from userspace. Do you mean the cpuid value should
be passed from userspace?
If so, this is not what we need. because we don't know which one cpu
the pod(containers) will use. and for skb-hash/classid
this helps us to pick the tx queue from a range. I don't understand
why this value should be passed from userspace. How ?
can you give me examples ?

BTW, this patch is the core of patchset.

Thanks.

--
Best regards, Tonghao