On Thursday 22 March 2007 01:53:54 Rafael J. Wysocki wrote: > On Thursday, 22 March 2007 00:39, Maxim wrote: > > On Thursday 22 March 2007 01:24:25 Rafael J. Wysocki wrote: > > > On Thursday, 22 March 2007 00:09, Maxim wrote: > > > > On Thursday 22 March 2007 00:39:02 you wrote: > > > > > On Wednesday, 21 March 2007 23:21, Pavel Machek wrote: > > > > > > Hi! > > > > > > > > > > > > > Starting with 2.6.21-rc1 suspend to ram and disk doesn't work > > > > > > > anymore on my system. > > > > > > > > > > > > > > I did a git-bisect and found that those commits break it: > > > > > > > > > > > > > > e3c7db621bed4afb8e231cb005057f2feb5db557 - [PATCH] [PATCH] PM: > > > > > > > Change code ordering in main.c > > > > > > > ed746e3b18f4df18afa3763155972c5835f284c5 - [PATCH] [PATCH] > > > > > > > swsusp: Change code ordering in disk.c > > > > > > > 259130526c267550bc365d3015917d90667732f1 - [PATCH] [PATCH] > > > > > > > swsusp: Change code ordering in user.c > > > > > > > > > > > > > > > > > > > (Yep, it was in my "to analyze" queue). > > > > > > > > > > > > > I already reported about it, but now i know the reason why > > > > > > > suspend breaks. > > > > > > > > > > > > > > The problem is that both cpu_up/cpu_down were allowed to sleep > > > > > > > until now, > > > > > > > and it did work because those functions could be called only in > > > > > > > process context > > > > > > > (the one that writes to /sys/devices/system/cpu/cpu*/online) or > > > > > > > idle thread that does smp_init()). > > > > > > > > > > > > > > But now they are called _after_ all tasks were suspended, so if > > > > > > > cpu_down tries for example to take a lock > > > > > > > that is taken by different process, it can't since the different > > > > > > > proccess is frozen and can't release the lock. > > > > > > > > > > > > > > > > > > > Thanks for detailed explanation. > > > > > > > > > > > > ...but, on my machine suspend works ok in -rc4. I'm not seeing this. > > > > > > > > > > > > ...by design, "frozen" tasks must not hold any locks. If frozen task > > > > > > holds a lock, that's a bug. > > > > > > > > > > > > > Or, it is also possible to revert this change. > > > > > > > > > > > > Are you using xfs? > > > > > > > > > > Well, this is the only case that can trigger it. There are no other > > > > > freezable > > > > > workqueues. > > > > > > > > > > Greetings, > > > > > Rafael > > > > > > > > > > > > > Hello, > > > > > > > > Yes, you are right and it is XFS > > > > > > > > System suspends and resumes with xfs and your patch correctly, > > > > > > Could you please sent this information to the list? I'd like it to reach > > > all > > > of the CCed parites. ;-) > > > > I did now ( sorry I just keep using this Answer command, instead of Answer > > to everybody) > > I didn't intend to send private email. > > > > > > > Of course I need to mention that I had to unload microcode > > > > update driver because it prevented resume, > > > > because it calls firmware loader helper, and again sleeps on > > > > lock > > > > > > This is interesting. Did it happen before or is it a regression? > > > > It is from the same group of bugs , I mean hang because cpu_up/down is > > called with frozen tasks > > Of course it didn't happen before those reordering commits were introduced > > Well, we want cpu_up/down to be called after processes have been frozen, for > various reasons (one of them being that applications shouldn't see us playing > with the CPUs). > > Thanks for reporting this, I'll have a look at the microcode update driver. > > > > > And also I noticed now that system oopses on second attempt to > > > > suspend ether to ram or disk > > > > in pci_restore_msi_state which is called indirectly by > > > > ahci_pci_device_resume, I will investigate this soon. > > > > > > Thanks. We've had such reports earlier, but I think the problem is still > > > unresolved. Any > > > additional information will be valuable. > > > > I will do my best, > > Also I want to note that the above problem is 100% repeatable, and happens > > independently whenever suspend to disk > > or suspend to ram was used in first successful try ( or at least, I got > > back-trace using kdb, after suspend to disk, after > > suspend to ram system hang, so I assume, that this it is same problem , > > because it didn't hang of first try) > > Thanks for the information. > > BTW, what's the last kernel you have tested? > > Rafael >
Hello, Thanks for quick response, I will continue to test my system I use literally latest Linus's git tree. The kernel that works is 2.6.20 , and except very weird hang that happens sometimes (1 in 5~6 times) on resume from ram, everything works I described it in http://lkml.org/lkml/2007/3/16/126 Regards, Maxim Levitsky - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/