From: Steven Rostedt <[EMAIL PROTECTED]>
Impact: quicken mcount calls that are not replaced by dyn ftrace
Dynamic ftrace no longer does on the fly recording of mcount locations.
The mcount locations are now found at compile time. The mcount
function no longer needs to store registers and call a stub function.
It can now just simply return.
Since there are some functions that do not get converted to a nop
(.init sections and other code that may disappear), this patch should
help speed up that code.
Signed-off-by: Steven Rostedt <[EMAIL PROTECTED]>
---
arch/powerpc/kernel/entry_32.S | 35 +----------------------------------
arch/powerpc/kernel/entry_64.S | 12 ------------
2 files changed, 1 insertions(+), 46 deletions(-)
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 7ecc0d1..d2c4035 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -1162,40 +1162,7 @@ machine_check_in_rtas:
#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)
- subi r3, r3, MCOUNT_INSN_SIZE
- .globl mcount_call
-mcount_call:
- bl ftrace_stub
- nop
- lwz r6, 8(r1)
- lwz r0, 44(r1)
- lwz r3, 12(r1)
- mtctr r0
- lwz r4, 16(r1)
- mtcr r6
- lwz r5, 20(r1)
- lwz r6, 24(r1)
- lwz r0, 52(r1)
- lwz r7, 28(r1)
- lwz r8, 32(r1)
- mtlr r0
- lwz r9, 36(r1)
- lwz r10,40(r1)
- addi r1, r1, 48
- bctr
+ blr
_GLOBAL(ftrace_caller)
/* Based off of objdump optput from glibc */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index e6d5284..b00982e 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -888,18 +888,6 @@ _GLOBAL(enter_prom)
#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
- /* Taken from output of objdump from lib64/glibc */
- mflr r3
- stdu r1, -112(r1)
- std r3, 128(r1)
- subi r3, r3, MCOUNT_INSN_SIZE
- .globl mcount_call
-mcount_call:
- bl ftrace_stub
- nop
- ld r0, 128(r1)
- mtlr r0
- addi r1, r1, 112
blr
_GLOBAL(ftrace_caller)
--
1.5.6.5
--
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