-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 El 2020-03-21 a las 12:37 +0100, Per Jessen escribió:
Dave Howorth wrote:
...
Ah, I think I understand. When the term 'interrupt' is used, Carlos and I think of a hardware capability. I gather you're thinking of an emulated software capability.
Yes, I'm looking at it as being "sat" inside a process. Hardware interrupts are usually not serviced by a process (kernel or user), but by an interrupt handler which then queues whatever it is (for processing). (I'm not sure how HPET interrupts are handled though).
Carlos' 'midnight commander' is just a process, accessing the fuse filesystem that is mounted with sshfs. As it has disabled SIGKILL, it must be in kernel mode. I think disabling SIGKILL can only be interpreted to mean "this _must_ complete, to avoid corrupting data".
If the connection dies, it dies. So, end the whatever is doing no matter what, there is no recovering. And in fact, it was doing nothing, that terminal had not been used in hours.
Plus as Carlos says, since when has a network connection disappearing been unexpected and have any effect on data integrity?
A network filesystem mount ?
I have a number of systems running with root on NFS, root is always mounted with "hard,intr". That means "wait forever" in the case of loss of the connection.
But in that case the mount is not done by a user program (mc in Carlos' case) via FUSE
A FUSE driver also has to use kernel services.
Going back to the very first post, I think the situation could have been remedied by resuming the machine at 192.168.1.134. Now Carlos' 'mc' would have been able to complete the "must complete" code and exit cleanly.
That's a terrible solution. In this case, I might have done it. What if the other machine is remote? But what if it is a laptop with a dying battery? If it refuses to hibernate the battery goes and all data in all processes is lost, which is much worse than a single mc process not exiting cleanly. I see no excuses for not hibernating no matter what. Poweroff succeded fast, it found no excuses to not power off. But of course, all possible data in everything is lost. - -- Cheers Carlos E. R. (from openSUSE 15.1 (Legolas)) -----BEGIN PGP SIGNATURE----- iHoEARECADoWIQQZEb51mJKK1KpcU/W1MxgcbY1H1QUCXnYP4Rwccm9iaW4ubGlz dGFzQHRlbGVmb25pY2EubmV0AAoJELUzGBxtjUfVbAMAn3a6Aae6nPcgeIjUPw67 xplkc1iAAKCDhRGMt75alD6BOL+ClCZsERQj6g== =8os2 -----END PGP SIGNATURE-----