Messages in this thread | | | Date | Wed, 14 May 2008 22:28:57 -0700 (PDT) | Subject | Re: [PATCH 2/2] ftrace: support for PowerPC | From | David Miller <> |
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From: Steven Rostedt <rostedt@goodmis.org> Date: Wed, 14 May 2008 23:49:44 -0400
> +#ifdef CONFIG_FTRACE > +#ifdef CONFIG_DYNAMIC_FTRACE > +_GLOBAL(mcount) > +_GLOBAL(_mcount) > + stwu r1,-48(r1) > + stw r3, 12(r1) > + stw r4, 16(r1) > + stw r5, 20(r1) > + stw r6, 24(r1) > + mflr r3 > + stw r7, 28(r1) > + mfcr r5 > + stw r8, 32(r1) > + stw r9, 36(r1) > + stw r10,40(r1) > + stw r3, 44(r1) > + stw r5, 8(r1)
Yikes, that's really expensive.
Can't you do a tail call and let the function you end up calling do all the callee-saved register pops onto the stack?
That's what I did on sparc.
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