Messages in this thread | | | Date | Thu, 30 Apr 2015 19:45:06 +0100 | Subject | Re: Regression: Requiring CAP_SYS_ADMIN for /proc/<pid>/pagemap causes application-level breakage | From | Mark Williamson <> |
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>> Something like this (see patch in attachment) > > THP is not covered. > > Any comments on kcmp() idea?
It seems like a modified kcmp() would also be a valid approach but, as you noted, probably speed-limited for our purposes. As you say, there is the option of a vector-oriented equivalent. It seems like a generally nice facility to have available in the kernel but my suspicion is that it wouldn't be optimal for us...
My thinking is that using soft-dirty might give us the best performance on platforms where it's available. We're only using fork() as a cunning/hacky way of tracking what pages change; soft-dirty would allow us to avoid that too, whereas using kcmp() would still require the forking overhead.
Does that make sense, or have I missed something?
Thanks, Mark
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