linux-stable/arch
Steven Rostedt (VMware) 518049d9d3 ftrace/x86_32: Remove support for non DYNAMIC_FTRACE
When DYNAMIC_FTRACE is enabled in the kernel, all the functions that can be
traced by the function tracer have a "nop" placeholder at the start of the
function. When function tracing is enabled, the nop is converted into a call
to the tracing infrastructure where the functions get traced. This also
allows for specifying specific functions to trace, and a lot of
infrastructure is built on top of this.

When DYNAMIC_FTRACE is not enabled, all the functions have a call to the
ftrace trampoline. A check is made to see if a function pointer is the
ftrace_stub or not, and if it is not, it calls the function pointer to trace
the code. This adds over 10% overhead to the kernel even when tracing is
disabled.

When an architecture supports DYNAMIC_FTRACE there really is no reason to
use the static tracing. I have kept non DYNAMIC_FTRACE available in x86 so
that the generic code for non DYNAMIC_FTRACE can be tested. There is no
reason to support non DYNAMIC_FTRACE for both x86_64 and x86_32. As the non
DYNAMIC_FTRACE for x86_32 does not even support fentry, and we want to
remove mcount completely, there's no reason to keep non DYNAMIC_FTRACE
around for x86_32.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-05-10 12:33:03 -04:00
..
alpha KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
arc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
arm A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
arm64 A collection of x86 and ARM bugfixes, and some improvements to documentation. 2019-03-31 08:55:59 -07:00
c6x KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
csky kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
h8300 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
hexagon KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
ia64 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
m68k KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
microblaze KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
mips A small batch of MIPS fixes for 5.1: 2019-03-19 10:50:15 -07:00
nds32 function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h 2019-04-29 17:17:22 -04:00
nios2 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
openrisc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
parisc function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h 2019-04-29 17:17:22 -04:00
powerpc powerpc fixes for 5.1 #4 2019-03-31 07:44:13 -07:00
riscv kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
s390 s390 update with improvements and bug fixes for 5.1-rc2 2019-03-28 08:35:32 -07:00
sh KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
sparc KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
um Merge branch 'for-linus-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2019-03-15 15:07:32 -07:00
unicore32 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
x86 ftrace/x86_32: Remove support for non DYNAMIC_FTRACE 2019-05-10 12:33:03 -04:00
xtensa KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
.gitignore
Kconfig Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00