On 7/8/25 9:01 AM, Eric Dumazet wrote:
On Mon, Jul 7, 2025 at 11:45 PM Daniel Sedlak <daniel.sedlak@xxxxxxxxx> wrote:
Hi Eric,
Thank you for your feedback.
On 7/7/25 2:48 PM, Eric Dumazet wrote:
On Mon, Jul 7, 2025 at 3:55 AM Daniel Sedlak <daniel.sedlak@xxxxxxxxx> wrote:
Currently, we have two memory pressure counters for TCP sockets [1],
which we manipulate only when the memory pressure is signalled through
the proto struct [2].
However, the memory pressure can also be signaled through the cgroup
memory subsystem, which we do not reflect in the netstat counters.
This patch adds a new counter to account for memory pressure signaled by
the memory cgroup.
OK, but please amend the changelog to describe how to look at the
per-cgroup information.
Sure, I will explain it more in v2. I was not sure how much of a
"storytelling" is appropriate in the commit message.
I am sure that having some details on how to find the faulty cgroup
would also help.
Right now, we have a rather fragile bpftrace script for that, but we
have a WIP patch for memory management, which will expose which cgroup
is having "difficulties", but that is still ongoing work.
Or do you have any suggestions on how we can incorporate this
information about "this particular cgroup is under pressure" into the
net subsystem? Maybe a log line?
Perhaps an additional trace point ?
Sounds good to me, we will incorporate that and send v2.
Ideally we could trace the cgroup path, or at least the pid.
Will try to do both, we will see.
Thanks!
Daniel
