Re: [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic

From: Christian Borntraeger
Date: Mon Sep 26 2022 - 08:10:39 EST




Am 26.09.22 um 10:06 schrieb Christian Borntraeger:


Am 23.09.22 um 09:53 schrieb Christian Borntraeger:
Am 23.09.22 um 09:21 schrieb Christian Borntraeger:
Peter,

as a heads-up. This commit (bisected and verified) triggers a
regression in our KVM on s390x CI. The symptom is that a specific
testcase (start a guest with next kernel and a poky ramdisk,
then ssh via vsock into the guest and run the reboot command) now
takes much longer (300 instead of 20 seconds). From a first look
it seems that the sshd takes very long to end during shutdown
but I have not looked into that yet.
Any quick idea?

Christian

the sshd seems to hang in virtio-serial (not vsock).

FWIW, sshd does not seem to hang, instead it seems to busy loop in
wait_port_writable calling into the scheduler over and over again.

-#define TASK_FREEZABLE 0x00002000
+#define TASK_FREEZABLE 0x00000000

"Fixes" the issue. Just have to find out which of users is responsible.