Re: [PATCH 0/2] More i387 state save/restore work

From: Linus Torvalds
Date: Sun Feb 19 2012 - 20:11:35 EST


Oh, and final comment - looking at the thing you pointed at, it looks
much more adventurous than my x86 FP state thing.

I always save things unconditionally, so that I don't have to do the
IPI or just in general care about the "oops, now I want things in
memory, not in some random CPU FP state". So mine is just a "writeback
cache", and only optimizes the reading things back: there is never any
dirty state in the CPU except when the process is actively using it.

That obviously does mean that I only optimize away the restore side,
not the save side. But it's *way* simpler, and considering that I just
spent almost a week trying to figure out FP state save bugs, simple is
good.

Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/