HEADS UP - major structure size changes in HEAD
aoiko at cc.ece.ntua.gr
Thu Jun 10 15:24:17 PDT 2010
On 10/06/2010 05:16 ÏÎ¼, Matthew Dillon wrote:
For the most part these tokens are not going to be held for more than
1uS or so, and often quite a bit less then that. This is because
most kernel operations only take long periods of time because they
actually block, and of course the token will be released if the thread
Take a vm_fault for example. The fault occurs and then blocks on I/O.
That might be 200ns. Then later on the I/O completes and the thread
wakes up and reacquires the token, then spends another 200ns with the
token held before returning from the fault.
I was thinking more about a soft pagefault, where you might need to
search the VM data structures, do a few allocations and wait for an IPI
roundtrip (for the pagetable invalidation).
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