Messages in this thread |  | | Date | Wed, 11 Jul 2001 11:52:26 +0200 | From | David Balazic <> | Subject | Re: Switching Kernels without Rebooting? |
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C. Slater (cslater@wcnet.org) wrote :
> Hi, i was just thinking about if it would be possible to switch kernels > without haveing to restart the entire system. Sort of a "Live kernel > replacement". It sort of goes along with the hot-swap-everything ideas. I > was thinking something like > - Take all the structs related to userspace memory and processes > - Save them to a reserved area of memory > - Halt the kernel, mostly > - Wipe kernel-space memory clean to avoid confusion > - Load new kernel into memory > - Replace all saved structures > - Start kernel running agin > > This seems like the easiest way to do it. The biggest problem is that there > would be somewhere about 30 seconds where all processes would be frozen.
This is not a problem at all, because UNIX does not guarantee that a process will get at least one CPU slice every X seconds. ( read : UNIX is not a real time system )
soft-suspend "freezes" processes for several hours anyway ...
Note that there is a patch for hot replacing a kernel, which is equivalent to rebooting, but much faster : Two Kernel Monte (Linux loading Linux on x86) http://www.scyld.com/products/beowulf/software/monte.html
> This could cause problems with tcp/ip connections timeing out say on a > webserver, but it would be more managable than a few minutes downtime to > restart the machine.
[ rest snipped ]
-- David Balazic -------------- "Be excellent to each other." - Bill & Ted - - - - - - - - - - - - - - - - - - - - - - - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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