There is no point in copying floating point regs when there
is no FPU and MATH_EMULATION is not selected.
Create a new CONFIG_PPC_FPU_REGS bool that is selected by
CONFIG_MATH_EMULATION and CONFIG_PPC_FPU, and use it to
opt out everything related to fp_state in thread_struct.
The asm const used only by fpu.S are opted out with CONFIG_PPC_FPU
as fpu.S build is conditionnal to CONFIG_PPC_FPU.
The following app spends approx 8.1 seconds system time on an 8xx
without the patch, and 7.0 seconds with the patch (13.5% reduction).
On an 832x, it spends approx 2.6 seconds system time without
the patch and 2.1 seconds with the patch (19% reduction).
void sigusr1(int sig) { }
int main(int argc, char **argv)
{
int i = 100000;
signal(SIGUSR1, sigusr1);
for (;i--;)
raise(SIGUSR1);
exit(0);
}
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7569070083e6cd5b279bb5023da601aba3c06f3c.1597770847.git.christophe.leroy@csgroup.eu
22 lines
606 B
Makefile
22 lines
606 B
Makefile
# SPDX-License-Identifier: GPL-2.0
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#
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# Makefile for the linux kernel.
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#
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CFLAGS_ptrace-view.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
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obj-y += ptrace.o ptrace-view.o
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obj-$(CONFIG_PPC_FPU_REGS) += ptrace-fpu.o
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obj-$(CONFIG_COMPAT) += ptrace32.o
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obj-$(CONFIG_VSX) += ptrace-vsx.o
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ifneq ($(CONFIG_VSX),y)
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obj-$(CONFIG_PPC_FPU_REGS) += ptrace-novsx.o
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endif
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obj-$(CONFIG_ALTIVEC) += ptrace-altivec.o
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obj-$(CONFIG_SPE) += ptrace-spe.o
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obj-$(CONFIG_PPC_TRANSACTIONAL_MEM) += ptrace-tm.o
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obj-$(CONFIG_PPC_ADV_DEBUG_REGS) += ptrace-adv.o
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ifneq ($(CONFIG_PPC_ADV_DEBUG_REGS),y)
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obj-y += ptrace-noadv.o
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endif
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