hi Rafael, on s390 we have a reproduceable testcase where, after all devices were suspended, a memory allocation results in disk IO. I know that this is similar to the current discussion about magically changing the gpf mask, but in our case the related allocation is triggered not by a device driver but directly by hibernation_snapshot. The call chain looks like this: STACK: 0 schedule+1796 [0x5a7af0] 1 io_schedule+98 [0x5a82ce] 2 sync_page_killable+4 [0x1ec424] 3 __wait_on_bit+204 [0x5a8bc4] 4 add_to_page_cache_locked+2 [0x1ec766] 5 shrink_page_list+2372 [0x1fc5b0] 6 shrink_list+2496 [0x1fd02c] 7 shrink_zone+932 [0x1fd3e0] 8 try_to_free_pages+668 [0x1fe4bc] 9 __alloc_pages_nodemask+1346 [0x1f5056] 10 __get_free_pages+76 [0x1f52dc] 11 __build_sched_domains+60 [0x144f98] 12 partition_sched_domains+696 [0x145dcc] 13 update_sched_domains+100 [0x146104] 14 notifier_call_chain+166 [0x5ae112] 15 raw_notifier_call_chain+44 [0x1800c4] 16 _cpu_down+586 [0x59f212] 17 disable_nonboot_cpus+354 [0x155ad2] 18 hibernation_snapshot+324 [0x1a7938] 19 hibernate+304 [0x1a7bcc] 20 state_store+130 [0x1a645e] 21 sysfs_write_file+264 [0x2b551c] 22 vfs_write+190 [0x23f98a] 23 sys_write+100 [0x23fb50] 24 sysc_noemu+16 [0x118ff6] a possible fix would be to call disable_nonboot_cpus before suspending the devices.. NOTE: this affects pm debug modes --- Since disable_nonboot_cpus triggers memory allocations we should call it before suspending the devices in hibernation_snapshot. Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx> --- kernel/power/hibernate.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -229,13 +229,9 @@ static int create_image(int platform_mod } error = platform_pre_snapshot(platform_mode); - if (error || hibernation_test(TEST_PLATFORM)) - goto Platform_finish; - - error = disable_nonboot_cpus(); - if (error || hibernation_test(TEST_CPUS) + if (error || hibernation_test(TEST_PLATFORM) || hibernation_testmode(HIBERNATION_TEST)) - goto Enable_cpus; + goto Platform_finish; local_irq_disable(); @@ -269,9 +265,6 @@ static int create_image(int platform_mod Enable_irqs: local_irq_enable(); - Enable_cpus: - enable_nonboot_cpus(); - Platform_finish: platform_finish(platform_mode); @@ -303,6 +296,10 @@ int hibernation_snapshot(int platform_mo if (error) goto Close; + error = disable_nonboot_cpus(); + if (error || hibernation_test(TEST_CPUS)) + goto Enable_cpus; + suspend_console(); error = dpm_suspend_start(PMSG_FREEZE); if (error) @@ -322,6 +319,8 @@ int hibernation_snapshot(int platform_mo dpm_resume_end(in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE); resume_console(); + Enable_cpus: + enable_nonboot_cpus(); Close: platform_end(platform_mode); return error; _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
