linux_dsm_epyc7002/arch/x86
Eric Dumazet 63cc8c7515 percpu: introduce DEFINE_PER_CPU_PAGE_ALIGNED() macro
While examining holes in percpu section I found this :

c05f5000 D per_cpu__current_task
c05f5000 D __per_cpu_start
c05f5004 D per_cpu__cpu_number
c05f5008 D per_cpu__irq_regs
c05f500c d per_cpu__cpu_devices
c05f5040 D per_cpu__cyc2ns

<Big Hole of about 4000 bytes>

c05f6000 d per_cpu__cpuid4_info
c05f6004 d per_cpu__cache_kobject
c05f6008 d per_cpu__index_kobject

<Big Hole of about 4000 bytes>

c05f7000 D per_cpu__gdt_page

This is because gdt_page is a percpu variable, defined with
a page alignement, and linker is doing its job, two times because of .o
nesting in the build process.

I introduced a new macro DEFINE_PER_CPU_PAGE_ALIGNED() to avoid
wasting this space. All page aligned variables (only one at this time)
are put in a separate
subsection .data.percpu.page_aligned, at the very begining of percpu zone.

Before patch , on a x86_32 machine :

.data.percpu                30232   3227471872
.data.percpu                22168   3227471872

Thats 8064 bytes saved for each CPU.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-25 07:03:46 +02:00
..
boot x86: relocs ELF handling - use SELFMAG instead of numeric constant 2008-05-04 20:04:45 +02:00
configs x86: add optimized inlining 2008-04-26 17:44:55 +02:00
crypto [CRYPTO] aes-x86-32: Remove unused return code 2008-04-21 10:19:21 +08:00
ia32 signals: x86 TS_RESTORE_SIGMASK 2008-04-30 08:29:37 -07:00
kernel percpu: introduce DEFINE_PER_CPU_PAGE_ALIGNED() macro 2008-05-25 07:03:46 +02:00
kvm KVM: LAPIC: ignore pending timers if LVTT is disabled 2008-05-18 14:39:39 +03:00
lguest x86: replace remaining __FUNCTION__ occurances 2008-04-17 17:40:57 +02:00
lib x86: fix csum_partial() export 2008-05-13 19:38:47 +02:00
mach-default spelling fixes: arch/i386/ 2007-10-20 01:13:56 +02:00
mach-es7000 i386: es7000 minor cleanups 2007-10-17 20:16:15 +02:00
mach-generic x86: coding style fixes to arch/x86/mach-generic/bigsmp.c 2008-04-17 17:40:48 +02:00
mach-rdc321x x86, rdc321x: remove watchdog file 2008-04-17 17:40:50 +02:00
mach-visws x86: fix compilation error in VisWS 2008-04-24 23:15:44 +02:00
mach-voyager x86, voyager: fix ioremap_nocache() 2008-04-30 23:15:34 +02:00
math-emu x86, fpu: split FPU state from task struct - v5 2008-04-19 19:19:55 +02:00
mm x86: fix crash on cpu hotplug on pat-incapable machines 2008-05-17 22:57:20 +02:00
oprofile x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c 2008-04-19 19:44:58 +02:00
pci PCI: Correct last two HP entries in the bfsort whitelist 2008-05-19 12:21:36 -07:00
power x86: coding style fixes to arch/x86/power/cpu_32.c 2008-04-17 17:40:50 +02:00
vdso x86: vdso ELF handling - use SELFMAG instead of numeric constant 2008-05-04 20:04:45 +02:00
video x86: video/fbdev.c: add MODULE_LICENSE 2008-05-04 20:04:46 +02:00
xen pageflags: use proper page flag functions in Xen 2008-04-28 08:58:22 -07:00
Kconfig x86: rdc: leds build/config fix 2008-05-10 19:31:45 +02:00
Kconfig.cpu x86: CONFIG_X86_ELAN fix 2008-04-30 23:15:35 +02:00
Kconfig.debug x86: Mark OPTIMIZE_INLINING broken 2008-04-30 20:07:22 -07:00
Makefile x86: add subarch support (for headers) to x86_64 2008-04-17 17:41:01 +02:00
Makefile_32.cpu x86: move i386 and x86_64 Makefiles to arch/x86 2007-10-25 22:27:34 +02:00