linux_dsm_epyc7002/arch/x86
Masahiro Yamada 8a78756eb5 kbuild: create object directories simpler and faster
For the out-of-tree build, scripts/Makefile.build creates output
directories, but this operation is not efficient.

scripts/Makefile.lib calculates obj-dirs as follows:

  obj-dirs := $(dir $(multi-objs) $(obj-y))

Please notice $(sort ...) is not used here.  Usually the result is
as many "./" as objects here.

For a lot of duplicated paths, the following command is invoked.

  _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))

Then, the costly shell command is run over and over again.

I see many points for optimization:

[1] Use $(sort ...) to cut down duplicated paths before passing them
    to system call
[2] Use single $(shell ...) instead of repeating it with $(foreach ...)
    This will reduce forking.
[3] We can calculate obj-dirs more simply.  Most of objects are already
    accumulated in $(targets).  So, $(dir $(targets)) is fine and more
    comprehensive.

I also removed ugly code in arch/x86/entry/vdso/Makefile.  This is now
really unnecessary.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
2017-11-16 09:07:35 +09:00
..
boot Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-07 09:42:35 -07:00
configs Merge branch 'x86/urgent' into x86/asm, to pick up fixes 2017-08-10 13:14:15 +02:00
crypto crypto: x86/twofish - Fix RBP usage 2017-09-20 17:42:38 +08:00
entry kbuild: create object directories simpler and faster 2017-11-16 09:07:35 +09:00
events perf/x86/intel/uncore: Correct num_boxes for IIO and IRP 2017-09-25 12:43:56 +02:00
hyperv tracing/hyper-v: Trace hyperv_mmu_flush_tlb_others() 2017-08-31 14:20:37 +02:00
ia32 x86/fpu: Rename fpu::fpstate_active to fpu::initialized 2017-09-26 09:43:36 +02:00
include Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-10-01 13:55:32 -07:00
kernel Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-10-01 13:55:32 -07:00
kvm Mixed bugfixes. Perhaps the most interesting one is a latent bug 2017-09-29 12:18:55 -07:00
lib x86/boot: Add early cmdline parsing for options with arguments 2017-07-18 11:38:06 +02:00
math-emu x86/fpu: Rename fpu__activate_curr() to fpu__initialize() 2017-09-26 09:43:44 +02:00
mm Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-10-01 13:55:32 -07:00
net x86: bpf_jit: small optimization in emit_bpf_tail_call() 2017-08-31 11:57:37 -07:00
oprofile
pci dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
platform Merge branch 'i2c/for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-09-09 14:18:40 -07:00
power dmi: Mark all struct dmi_system_id instances const 2017-09-14 11:59:30 +02:00
purgatory kasan: do not sanitize kexec purgatory 2017-03-31 17:13:30 -07:00
ras x86/mce: Merge mce_amd_inj into mce-inject 2017-06-14 07:32:07 +02:00
realmode x86/boot/realmode: Check for memory encryption on the APs 2017-07-18 11:38:04 +02:00
tools
um um: remove a stray tab 2017-09-13 22:36:27 +02:00
video
xen xen: fixes for 4.14-rc3 2017-09-29 12:24:28 -07:00
.gitignore
Kbuild Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-07 09:25:15 -07:00
Kconfig libnvdimm for 4.14 2017-09-11 13:10:57 -07:00
Kconfig.cpu
Kconfig.debug Merge branch 'x86/asm' into locking/core 2017-08-18 10:29:54 +02:00
Makefile x86/build: Use cc-option to validate stack alignment parameter 2017-08-21 09:53:15 +02:00
Makefile_32.cpu kbuild: remove cc-option-align 2017-06-25 12:43:00 +09:00
Makefile.um