linux/arch
Vineet Gupta 6aae3425aa ARC: mm: remove __ARCH_USE_5LEVEL_HACK
Patch series "elide extraneous generated code for folded p4d/pud/pmd", v3.

This series came out of seemingly benign excursion into
understanding/removing __ARCH_USE_5LEVEL_HACK from ARC port showing some
extraneous code being generated despite folded p4d/pud/pmd

| bloat-o-meter2 vmlinux-[AB]*
| add/remove: 0/0 grow/shrink: 3/0 up/down: 130/0 (130)
| function                                     old     new   delta
| free_pgd_range                               548     660    +112
| p4d_clear_bad                                  2      20     +18

The patches here address that

| bloat-o-meter2 vmlinux-[BF]*
| add/remove: 0/2 grow/shrink: 0/1 up/down: 0/-386 (-386)
| function                                     old     new   delta
| pud_clear_bad                                 20       -     -20
| p4d_clear_bad                                 20       -     -20
| free_pgd_range                               660     314    -346

The code savings are not a whole lot, but still worthwhile IMHO.

This patch (of 5):

With paging code made 5-level compliant, this is no longer needed.  ARC
has software page walker with 2 lookup levels (pgd -> pte)

This was expected to be non functional change but ended with slight
code bloat due to needless inclusions of p*d_free_tlb() macros which
will be addressed in further patches.

| bloat-o-meter2 vmlinux-[AB]*
| add/remove: 0/0 grow/shrink: 2/0 up/down: 128/0 (128)
| function                                     old     new   delta
| free_pgd_range                               546     656    +110
| p4d_clear_bad                                  2      20     +18
| Total: Before=4137148, After=4137276, chg 0.000000%

Link: http://lkml.kernel.org/r/20191016162400.14796-2-vgupta@synopsys.com
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 06:29:19 -08:00
..
alpha generic ioremap support 2019-11-28 10:57:12 -08:00
arc ARC: mm: remove __ARCH_USE_5LEVEL_HACK 2019-12-01 06:29:19 -08:00
arm dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
arm64 dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
c6x dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
csky dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
h8300 h8300: Move EXCEPTION_TABLE to RO_DATA segment 2019-11-04 18:12:55 +01:00
hexagon dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
ia64 dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
m68k dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
microblaze dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
mips dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
nds32 dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
nios2 dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
openrisc dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
parisc dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
powerpc dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
riscv generic ioremap support 2019-11-28 10:57:12 -08:00
s390 generic ioremap support 2019-11-28 10:57:12 -08:00
sh dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
sparc dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
um Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 10:42:40 -08:00
unicore32 generic ioremap support 2019-11-28 10:57:12 -08:00
x86 dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
xtensa dma-mapping updates for 5.5-rc1 2019-11-28 11:16:43 -08:00
.gitignore
Kconfig New tracing features: 2019-11-27 11:42:01 -08:00