Disable hibernate -- Live media shouldn't allow it?
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When booting from removable media, you may end up mounting a swap partition on an internal hard disk, thus enabling hibernation. Inadvertently hibernating ( perhaps in response to ACPI HOT event ) is silly since the system can not be resumed. Is there a flag somewhere to prevent hibernating? Shouldn't there be and shouldn't it be disabled by default?
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Quoted 9 lines · Phillip Susi
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Hash: SHA1When booting from removable media, you may end up mounting a swap partition on an internal hard disk, thus enabling hibernation. Inadvertently hibernating ( perhaps in response to ACPI HOT event ) is silly since the system can not be resumed. Is there a flag somewhere to prevent hibernating? Shouldn't there be and shouldn't it be disabled by default?
I don't think we have a good definition of "removable media".
Also, you usually can remove a normally non-removable disk while hibernated, so I just don't see why we should disable it in any case.
That said, it is reasonable to expect live CDs not to configure the system to hibernate in response to overheating etc. But that's not a problem we can address in the kernel.
Thanks,
Rafael
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I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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Quoted 3 lines · Rafael J. Wysocki
That said, it is reasonable to expect live CDs not to configure the system to hibernate in response to overheating etc. But that's not a problem we can address in the kernel.
How would that be configured? Initiating the hibernation in response to api HOT event is done in the kernel isn't it?
Setting the policy obviously isn't something that can be done in the kernel, but it should provide for the ability to have such a policy by having a knob user mode has to switch on when it thinks hibernation makes any kind of sense. Simply enabling a swap shouldn't be all it takes -- you should have to specify that yes, this swap is configured for hibernate/resume.
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Quoted 10 lines · Phillip Susi
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Hash: SHA1Quoted 3 lines · Rafael J. Wysocki
That said, it is reasonable to expect live CDs not to configure the system to hibernate in response to overheating etc. But that's not a problem we can address in the kernel.
How would that be configured? Initiating the hibernation in response to api HOT event is done in the kernel isn't it?
No, I don't think so. At least I'm not aware of that. Do you have any pointers to the kernel code doing that?
Quoted 6 lines
Setting the policy obviously isn't something that can be done in the kernel, but it should provide for the ability to have such a policy by having a knob user mode has to switch on when it thinks hibernation makes any kind of sense. Simply enabling a swap shouldn't be all it takes -- you should have to specify that yes, this swap is configured for hibernate/resume.
Actually, it is not all it takes. You need to point the hibernate code to the specific swap through the resume= kernel command line option (there is a default, though).
Thanks,
Rafael
Quoted 13 lines
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Signature · 2 lines
I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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Quoted 2 lines · Rafael J. Wysocki
No, I don't think so. At least I'm not aware of that. Do you have any pointers to the kernel code doing that?
No, but I also can't see anything in user mode doing it either, which is why I'm asking. I assumed that since this is an emergency response required by the ACPI spec, that it would be implemented by the kernel ACPI driver.
Quoted 3 lines
Actually, it is not all it takes. You need to point the hibernate code to the specific swap through the resume= kernel command line option (there is a default, though).
That's needed to resume, but not to hibernate. Simply doing a swapon is enough to enable hibernating. Checking that you have a valid resume= kernel argument probably would be a sane thing to do before allowing hibernation, but this isn't currently the case.
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