Messages in this thread | | | Date | Wed, 22 Oct 2008 09:58:06 +0100 | From | Alex Howells <> | Subject | Re: [RFC] Kernel version numbering scheme change |
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Hey Valdis
>> Requirements for me to put a kernel on a given server would be: > >> * supports the hardware > The problem is that "supports" is often a fuzzy jello-like substance you > try to nail to a tree. You mention the R8169 and e1000 drivers - if they > bring the device up, but have issues under corner cases, is that "supports" > or not?
Oh agreed, this is all very "use case" specific. I'm making all of the following statements based on the specific hardware we use, and assuming 'stability' based on the kernel/hardware passing a number of tests.
>> * no security holes [in options I enable] > Similarly for "no security holes". At *BEST*, you'll get "no *known* *major* > security holes", unless you feel like auditing the entire source tree. There's > a whole slew of bugs that we can't even agree if they *are* security bugs or > just plain bugs - see Linus's rant on the subject a few months back.
Agreed. No *known* *major* security holes is fine here.
>> * works reliably, under load/stress. > And you win the trifecta - I don't think we've *ever* shipped a Linux kernel > that worked reliably under the proper "beat on the scheduler/VM corner case" > load/stress testing. Again, the best you can hope for is "doesn't fall over > under non-pathological non-corner-case loads when sufficient resources are > available so the kernel has a fighting chance". Doing 'make -j100' on a > single Core2 Duo is gonna be painful, no matter what.
Well the typical tests outlined above are:
* random size file creation/deletion, lots of files * memory allocation, and freeing up again * stressing the CPU a bit with one process, then forking 25-50 processes to (trivially) test scheduler * testing network I/O by rapidly/concurrently fetching many small files via HTTP, and a few large ones.
The end goal is simply to get a server which doesn't crash under "normal" operating conditions. The bugs I referred to in e1000/forcedeth and r8169 either stop it PXE booting (a requirement for our environment!) or can *easily* be made to oops / stop working.
Alex
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