Messages in this thread | | | Date | Wed, 17 Aug 2005 14:10:34 +0900 | From | Hiro Yoshioka <> | Subject | Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll() |
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Akira,
Thanks for your suggestions.
On 8/17/05, Akira Tsukamoto <akira-t@s9.dion.ne.jp> wrote: > Anyway, going back to copy_user topic, > big remaining issues are > 1)store/restore floating point register (80/64bytes) twice every time by > surrounding with kernel_fpu_begin()/kernel_fpu_end() is big penalty
I don't know. If nobody uses MMX/XMM, then there is no need to save and restore.
> 2)after pagefault not always come back to copy function and corrupts fp register
I'm trying to understand this mechanism but I don't understand very well.
> 3)disabling long preemption > Please correct me if I am wrong. > > I tried to implement fpsave inside pagefault handler once and here is my junk; > http://www.suna-asobi.com/~akira-t/linux/k7-copy-user/K7-copy_47_with_fpusave_not_finished.patch > never had a time to finish it. Hiro, does it help you?
Thanks. I'm reading your patch but could not understand very well.
I'll ask you.
Regards, Hiro -- Hiro Yoshioka mailto:hyoshiok at miraclelinux.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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