Wondering if this was the correct way to patch my kernel for CFLAGS?

Question

Hello. I use to build the zen-sources kernel but stopped many months ago. I didn't really need all of those patches but I did miss the Custom CFLAGS/MAKEFLAGS option that the zen kernel had. I also missed the 432HZ Timer frequency setting available in the zen patch.
So I researched a bit and grabbed these parts from the zen patch to add to the Arch kernel:
For the CFLAGS/MAKEFLAGS
diff --git a/Makefile b/Makefile
index 1ab3ebf..472fe73 100644
--- a/Makefile
+++ b/Makefile
@@ -328,13 +328,12 @@ CHECK = sparse
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void $(CF)
MODFLAGS = -DMODULE
-CFLAGS_MODULE = $(MODFLAGS)
-AFLAGS_MODULE = $(MODFLAGS)
-LDFLAGS_MODULE =
-CFLAGS_KERNEL =
+CFLAGS_MODULE = $(MODFLAGS) $(CUSTOM_CFLAGS)
+AFLAGS_MODULE = $(MODFLAGS)
+LDFLAGS_MODULE =
+CFLAGS_KERNEL = $(CUSTOM_CFLAGS)
AFLAGS_KERNEL =
# Use LINUXINCLUDE when you must reference the include/ directory.
# Needed to be compatible with the O= option
LINUXINCLUDE := -Iinclude \
@@ -344,6 +343,9 @@ LINUXINCLUDE := -Iinclude \
KBUILD_CPPFLAGS := -D__KERNEL__
+# Apply custom flags
+KBUILD_CFLAGS += $(CUSTOM_CFLAGS)
+
KBUILD_CFLAGS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-fno-strict-aliasing -fno-common \
-Werror-implicit-function-declaration
diff --git a/init/Kconfig b/init/Kconfig
index 6a5c5fe..7b2f4b5 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -672,6 +734,32 @@ config CC_OPTIMIZE_FOR_SIZE
If unsure, say Y.
+menu "Custom Build Flags"
+
+config CUSTOM_CFLAGS
+ string "Custom CFLAGS for kernel"
+ default ""
+ help
+ You can use this to easily set custom gcc CFLAGS to be used for the
+ entire kernel (including modules).
+
+ No warning for you, i can't fix stupidity.
+
+ If unsure, leave blank.
+
+config CUSTOM_MAKEFLAGS
+ string "Custom MAKEFLAGS for kernel"
+ default ""
+ help
+ You can use this to easily set custom MAKEFLAGS to be used for building
+ the entire kernel.
+
+ (Or just use the options when you run make?)
+
+ If unsure, leave blank.
+
+endmenu
+
config SYSCTL
bool
and for the Timer frequency:
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz
index 94fabd5..7a830d4 100644
--- a/kernel/Kconfig.hz
+++ b/kernel/Kconfig.hz
@@ -4,7 +4,7 @@
choice
prompt "Timer frequency"
- default HZ_250
+ default HZ_1000
help
Allows the configuration of the timer frequency. It is customary
to have the timer interrupt run at 1000 Hz but 100 Hz may be more
@@ -23,6 +23,30 @@ choice
with lots of processors that may show reduced performance if
too many timer interrupts are occurring.
+ config HZ_108
+ bool "108 HZ"
+ help
+ 864 HZ is the best value for desktop systems. Most responsive
+ out of all the options. This is for Eight core/Processor systems only
+ as timer frequencies * NR_CPUS = actual frequency.
+ Try this if you have a Eight Core/Processor processor system and a desktop environment.
+
+ config HZ_144
+ bool "144 HZ"
+ help
+ 864 HZ is the best value for desktop systems. Most responsive
+ out of all the options. This is for Six Core/Processor systems only
+ as timer frequencies * NR_CPUS = actual frequency.
+ Try this if you have a Six core/processor system and a desktop environment.
+
+ config HZ_216
+ bool "216 HZ"
+ help
+ 864 HZ is the best value for desktop systems. Most responsive
+ out of all the options. This is for Quad-core/Processor systems only
+ as timer frequencies * number of processors = actual frequency.
+ Try this if you have a quad-core/dual processor system and a desktop environment.
+
config HZ_250
bool "250 HZ"
help
@@ -39,6 +63,22 @@ choice
on SMP and NUMA systems and exactly dividing by both PAL and
NTSC frame rates for video and multimedia work.
+ config HZ_432
+ bool "432 HZ"
+ help
+ 864 HZ is the best value for desktop systems. Most responsive
+ out of all the options. This is for Dual Core/Processor systems only
+ as timer frequencies * number of processors = actual frequency.
+ Try this if you have a dual-core/dual processor system and a desktop environment.
+
+ config HZ_864
+ bool "864 HZ"
+ help
+ 864 HZ is the best value for desktop systems. Most responsive
+ out of all the options. The only reason it is not default is
+ because it may break few drivers. Give it a try if you have
+ a desktop :).
+
config HZ_1000
bool "1000 HZ"
help
@@ -50,8 +90,13 @@ endchoice
config HZ
int
default 100 if HZ_100
+ default 108 if HZ_108
+ default 144 if HZ_144
+ default 216 if HZ_216
default 250 if HZ_250
default 300 if HZ_300
+ default 432 if HZ_432
+ default 864 if HZ_864
default 1000 if HZ_1000
config SCHED_HRTICK
Well the code was added to my make menuconfig kernel settings, and is in the .config of my newly compiled kernel..... I'm just wondering if I did this correctly. (I'm pretty sure that I did a crappy job of patching since I just grabbed the pieces of the zen patch that I thought were the correct one)..... This is the message from the patch:
patching file Makefile
patching file init/Kconfig
patch unexpectedly ends in middle of line
Hunk #1 succeeded at 734 with fuzz 2.
patching file kernel/Kconfig.hz
patch unexpectedly ends in middle of line
Hunk #4 succeeded at 90 with fuzz 1.
So if someone can tell me a better way to patch the kernel26 for custom CFLAGS and 432HZ Timer frequency (for dual core) I would appreciate it. Thanks.

Answer 1

I'm still trying to find out if I needed to patch any other parts of the kernel source when I added CFLAGS to the kernel modules? I also would like to know if I did the Timing part correctly (so I could use the 432HZ setting for a dual core).
..... so far this kernel has worked ok for the last 4 days. Does anybody know how I can benchmark it and compare it to other kernels that I have built with different settings?
Any info is appreciated.
Last edited by methuselah (2009-05-19 15:20:55)