* Ingo Molnar <[EMAIL PROTECTED]> wrote:
> the 'migrate read count' solution seems more promising, as it would
> keep other parts of the RCU code unchanged. [ But it seems to break
> the nice 'flip pointers' method you found to force a grace period. If
> a 'read section' can migrate from one CPU to another then it can
> migrate back as well, at which point it cannot have the 'old' pointer.
> Maybe it would still work better than no flip pointers. ]
the flip pointer method could be made to work if we had a NR_CPUS array
of 'current RCU pointer' values attached to the task - and that array
would be cleared if the task exits the read section. But this has memory
usage worries with large NR_CPUS. (full clearing of the array can be
avoided by using some sort of 'read section generation' counter attached
to each pointer)
Ingo
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
