Bug 15006

Summary:	Network testing packet generator (NET_PKTGEN) module breaks suspend to ram
Product:	Networking	Reporter:	Ciprian Dorin Craciun (ciprian.craciun)
Component:	Other	Assignee:	Rafael J. Wysocki (rjw)
Status:	RESOLVED PATCH_ALREADY_AVAILABLE
Severity:	normal	CC:	rjw
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.32.3	Subsystem:
Regression:	No	Bisected commit-id:
Bug Depends on:
Bug Blocks:	7216, 56331
Attachments:	`dmesg` output kernel config `dmesg` for a working build Net / pktgen: Fix freezing

Description Ciprian Dorin Craciun 2010-01-08 07:49:39 UTC

(Note: I'm not sure if I should submit this bug to the "Power management" or "Networking" component, so please correct me.)

So, the problem is simple (at least to diagnostic):
* when enabling `CONFIG_NET_PKTGEN=y`,
* and I try to suspend to ram (by either `s2ram -f`, or manually with `echo mem >/proc/...`,
* the system fails to suspend with the following error in `dmesg`:
~~~~~~~~
[   36.576132] Freezing user space processes ... (elapsed 0.00 seconds) done.
[   36.576215] Freezing remaining freezable tasks ... 
[   49.493737] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 1
[   56.577262] 
[   56.577265] Freezing of tasks failed after 20.00 seconds (2 tasks refusing to freeze):
[...snip...]
[   56.582777]  kpktgend_0
[   56.582779]  kpktgend_1
[   56.582783] 
[   56.582785] Restarting tasks ... done.
~~~~~~~~

How I've solved it: I've disabled the module with `CONFIG_NET_PKTGEN=n`.

Attached is my config file and dmesg output. (One note about the config file: every module I think I'll ever use is built inside the kernel (`=y`), so the resulting kernel is large (7MB), and thus the problem may arise only in corroboration with one of the modules I've enabled.)

Comment 1 Ciprian Dorin Craciun 2010-01-08 07:53:44 UTC

Created attachment 24481 [details]
`dmesg` output

Comment 2 Ciprian Dorin Craciun 2010-01-08 07:55:15 UTC

Created attachment 24482 [details]
kernel config

Comment 3 Zhang Rui 2010-01-18 02:48:59 UTC

please also attach the dmesg output when CONFIG_NET_PKTGEN=n.

Comment 4 Ciprian Dorin Craciun 2010-01-18 07:30:28 UTC

Created attachment 24613 [details]
`dmesg` for a working build

Comment 5 Rafael J. Wysocki 2010-01-29 20:50:10 UTC

Created attachment 24782 [details]
Net / pktgen: Fix freezing

Sorry for the delay.

Can you please test with this patch applied?

Comment 6 Rafael J. Wysocki 2010-01-29 23:15:41 UTC

And with CONFIG_NET_PKTGEN=y, of course.

Comment 7 Ciprian Dorin Craciun 2010-02-02 11:26:57 UTC

Thanks! I confirm that your patch works when applied on top of the latest 2.6.32.7. (Of course with CONFIG_NET_PKTGEN=y, and checked to see if I have kpktgend kernel threads.)

Comment 8 Rafael J. Wysocki 2010-02-02 20:05:14 UTC

Handled-By : Rafael J. Wysocki <rjw@sisk.pl>

Comment 9 Rafael J. Wysocki 2010-02-02 20:05:44 UTC

Thanks for testing, I'll push the patch upstream soon.