dashboard/config/linux: disable CONFIG_PCPU_DEV_REFCNT, add netdev_unregister_timeout_secs

Disable CONFIG_PCPU_DEV_REFCNT, it should provide refcount underflow detection.
Set netdev_unregister_timeout_secs to the timeout used for task hung detection,
it should avoid false "unregister_netdevice: waiting for DEV to become free" crashes.

5 files changed, 7 insertions, 5 deletions

diff --git a/dashboard/config/linux/bits/arm.yml b/dashboard/config/linux/bits/arm.yml
index e53da4dde..a67e4f954 100644
--- a/dashboard/config/linux/bits/arm.yml
+++ b/dashboard/config/linux/bits/arm.yml
@@ -8,7 +8,7 @@ shell:
 config:
  # We reduce number of vivid/netrom/rose/hcd devices to 2 because we use at most 2 procs
  # with emulation and creating these devices takes time during boot.
- - CMDLINE: [append, "root=/dev/vda console=ttyAMA0 vmalloc=512M watchdog_thresh=165 workqueue.watchdog_thresh=420 dummy_hcd.num=2"]
+ - CMDLINE: [append, "root=/dev/vda console=ttyAMA0 vmalloc=512M watchdog_thresh=165 workqueue.watchdog_thresh=420 sysctl.net.core.netdev_unregister_timeout_secs=420 dummy_hcd.num=2"]
  - CMDLINE_EXTEND
  # See the comment in x86_64.yml re these numbers.
  - RCU_CPU_STALL_TIMEOUT: 300
diff --git a/dashboard/config/linux/bits/arm64.yml b/dashboard/config/linux/bits/arm64.yml
index ebf6637b7..429e2bf6e 100644
--- a/dashboard/config/linux/bits/arm64.yml
+++ b/dashboard/config/linux/bits/arm64.yml
@@ -9,7 +9,7 @@ shell:
 config:
  # We reduce number of vivid/netrom/rose/hcd devices to 2 because we use at most 2 procs
  # with emulation and creating these devices takes time during boot.
- - CMDLINE: [append, "root=/dev/vda console=ttyAMA0 watchdog_thresh=165 workqueue.watchdog_thresh=420 dummy_hcd.num=2"]
+ - CMDLINE: [append, "root=/dev/vda console=ttyAMA0 watchdog_thresh=165 workqueue.watchdog_thresh=420 sysctl.net.core.netdev_unregister_timeout_secs=420 dummy_hcd.num=2"]
  # Was dropped in "arm64: Drop support for CMDLINE_EXTEND".
  - CMDLINE_EXTEND: [-v5.12]
  # See the comment in x86_64.yml re these numbers.
diff --git a/dashboard/config/linux/bits/base.yml b/dashboard/config/linux/bits/base.yml
index cec6fb19d..4d164d8bb 100644
--- a/dashboard/config/linux/bits/base.yml
+++ b/dashboard/config/linux/bits/base.yml
@@ -87,6 +87,8 @@ config:
 
  # CONFIG_REFCOUNT_FULL was removed in fb041bb7c0a9.
  - REFCOUNT_FULL: [-v5.5]
+ # Added in 919067cc845f ("net: add CONFIG_PCPU_DEV_REFCNT") and should appear in v5.13.
+ - PCPU_DEV_REFCNT: [n, linux-next]
 
  # This config does not add any debug checks (only debug output).
  - DEBUG_KOBJECT: n
diff --git a/dashboard/config/linux/bits/riscv64.yml b/dashboard/config/linux/bits/riscv64.yml
index cb7e2a397..361ebdbf6 100644
--- a/dashboard/config/linux/bits/riscv64.yml
+++ b/dashboard/config/linux/bits/riscv64.yml
@@ -6,7 +6,7 @@ shell:
  - make kvm_guest.config
 
 config:
- - CMDLINE: [append, "dummy_hcd.num=2 watchdog_thresh=165 workqueue.watchdog_thresh=420"]
+ - CMDLINE: [append, "dummy_hcd.num=2 watchdog_thresh=165 workqueue.watchdog_thresh=420 sysctl.net.core.netdev_unregister_timeout_secs=420"]
  - CMDLINE_EXTEND
  # See the comment in x86_64.yml re these numbers.
  - RCU_CPU_STALL_TIMEOUT: 300
diff --git a/dashboard/config/linux/bits/x86_64.yml b/dashboard/config/linux/bits/x86_64.yml
index a7d67565b..22263e34d 100644
--- a/dashboard/config/linux/bits/x86_64.yml
+++ b/dashboard/config/linux/bits/x86_64.yml
@@ -10,7 +10,7 @@ config:
  # root=/dev/sda is not necessary correct, but it's a common setting and user arguments are appended
  # to the builtin command line, so user can always override this.
  # vsyscall=native required to run x86_64 executables on android kernels (it disables VDSO by default).
- - CMDLINE: [append, "root=/dev/sda console=ttyS0 vsyscall=native numa=fake=2 kvm-intel.nested=1 spec_store_bypass_disable=prctl nopcid vivid.n_devs=16 vivid.multiplanar=1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2 netrom.nr_ndevs=16 rose.rose_ndevs=16 dummy_hcd.num=8 watchdog_thresh=55 workqueue.watchdog_thresh=140"]
+ - CMDLINE: [append, "root=/dev/sda console=ttyS0 vsyscall=native numa=fake=2 kvm-intel.nested=1 spec_store_bypass_disable=prctl nopcid vivid.n_devs=16 vivid.multiplanar=1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2 netrom.nr_ndevs=16 rose.rose_ndevs=16 dummy_hcd.num=8 watchdog_thresh=55 workqueue.watchdog_thresh=140 sysctl.net.core.netdev_unregister_timeout_secs=140"]
  - CMDLINE_BOOL
 
  # Deterministic hang/stall detection.
@@ -25,7 +25,7 @@ config:
  # 2. Then softlockup detector.
  #    kernel.watchdog_thresh = 55 detects stalls after 110-132 secs.
  #
- # 3. Then hung tasks and workqueue stalls.
+ # 3. Then hung tasks, workqueue stalls and netdev unregister hangs.
  #    Unfortunately we can't separate them because that would require setting "no output" timeout to 10+ minutes.
  #    watchdog_thresh=140 and DEFAULT_HUNG_TASK_TIMEOUT=140 both result in detection after 140-280 secs.
  #