Re: [PATCH] Make math_state_restore() save and restore the interrupt flag

From: Linus Torvalds
Date: Sat Feb 01 2014 - 20:47:56 EST


On Sat, Feb 1, 2014 at 5:43 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> What does the inner if clause do? It looks like it returns either way...

Suresh broke it with his suggested version.

The inner if-statement is supposed to avoid the stts *if* we had used
math *and* the FPU restore worked.

But with the extra "else" that Suresh added, it now always avoids the
stts for the eager-fpu case, which breaks the whole logic for "hey, if
the process hadn't used math, we don't waste time restoring data that
doesn't exist". And, as you say, making the inner if clause pointless.

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/