Messages in this thread |  | | | Subject | Re: [PATCH] Use uname not sysctl to get the kernel revision | | From | Alan Cox <> | | Date | Thu, 13 Jul 2006 00:07:44 +0100 |
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Ar Mer, 2006-07-12 am 16:26 -0600, ysgrifennodd Eric W. Biederman: > If the lock is not short lived then the release is like to be a long > ways off. If the lock is not highly contended then you are not likely > to hit the window when someone else as the contended lock. > > How frequent are highly contended short lived locks in user space?
I'm not sure it matters.
If you want to do the job right then do this
- Stick an indicator of how much else wants to run on this CPU in the vsyscall page or similar location
In your locks you can now do
while(try_and_grab_lock() == FAILED) { if (kernelpage->waiting > 0) sys_somelockwaitthing() } Furthermore the kernel can be intelligent about the waiting indicator for power or other global scheduling reasons
[Disclaimer: There is a patent issue around this technique but its not one that will impact GPL code as permissions are given for GPL use.]
Alan
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