Hi,
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.
Please review, test and apply. It seems to survive my usual battery of
multibench, hakcbench etc.
Thx,
-Vineet
---
Changes since v2 [3]
- No code changes: Fixed the silly typos and collected ACKs
Changes since v1 [1]
- Per Linus Sugestion remvoed the extra ifdey'ery (hence not
accumulating Kirill's ACks)
- Added the RFC patch for pmd_free_tlb() after discussions [2]
- Also throwing in the ARC patch which started this all (so we get the
full context of patchset) - I'm ok if this goes via mm tree, should
be non contentious and can drop this too if Andrew thinks otherwise
[1] http://lists.infradead.org/pipermail/linux-snps-arc/2019-October/006263.html
[2] http://lists.infradead.org/pipermail/linux-snps-arc/2019-October/006277.html
[3] http://lists.infradead.org/pipermail/linux-snps-arc/2019-October/006307.html
---
Vineet Gupta (5):
ARC: mm: remove __ARCH_USE_5LEVEL_HACK
asm-generic/tlb: stub out pud_free_tlb() if nopud ...
asm-generic/tlb: stub out p4d_free_tlb() if nop4d ...
asm-generic/tlb: stub out pmd_free_tlb() if nopmd
asm-generic/mm: stub out p{4,u}d_clear_bad() if
__PAGETABLE_P{4,u}D_FOLDED
arch/arc/include/asm/pgtable.h | 1 -
arch/arc/mm/fault.c | 10 ++++++++--
arch/arc/mm/highmem.c | 4 +++-
include/asm-generic/4level-fixup.h | 1 -
include/asm-generic/5level-fixup.h | 1 -
include/asm-generic/pgtable-nop4d.h | 2 +-
include/asm-generic/pgtable-nopmd.h | 2 +-
include/asm-generic/pgtable-nopud.h | 2 +-
include/asm-generic/pgtable.h | 11 +++++++++++
include/asm-generic/tlb.h | 4 ----
mm/pgtable-generic.c | 9 +++++++++
11 files changed, 34 insertions(+), 13 deletions(-)
--
2.20.1
... independent of __ARCH_HAS_5LEVEL_HACK
This came up when removing __ARCH_HAS_5LEVEL_HACK for ARC as code bloat.
With this patch we see the following code reduction
| bloat-o-meter2 vmlinux-C-elide-pud_free_tlb vmlinux-D-elide-p4d_free_tlb
| add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-104 (-104)
| function old new delta
| free_pgd_range 552 422 -130
| Total: Before=4137172, After=4137042, chg -1.000000%
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
---
include/asm-generic/5level-fixup.h | 1 -
include/asm-generic/pgtable-nop4d.h | 2 +-
include/asm-generic/tlb.h | 2 --
3 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/include/asm-generic/5level-fixup.h b/include/asm-generic/5level-fixup.h
index f6947da70d71..4c74b1c1d13b 100644
--- a/include/asm-generic/5level-fixup.h
+++ b/include/asm-generic/5level-fixup.h
@@ -51,7 +51,6 @@ static inline int p4d_present(p4d_t p4d)
#undef p4d_free_tlb
#define p4d_free_tlb(tlb, x, addr) do { } while (0)
#define p4d_free(mm, x) do { } while (0)
-#define __p4d_free_tlb(tlb, x, addr) do { } while (0)
#undef p4d_addr_end
#define p4d_addr_end(addr, end) (end)
diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h
index aebab905e6cd..ce2cbb3c380f 100644
--- a/include/asm-generic/pgtable-nop4d.h
+++ b/include/asm-generic/pgtable-nop4d.h
@@ -50,7 +50,7 @@ static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
*/
#define p4d_alloc_one(mm, address) NULL
#define p4d_free(mm, x) do { } while (0)
-#define __p4d_free_tlb(tlb, x, a) do { } while (0)
+#define p4d_free_tlb(tlb, x, a) do { } while (0)
#undef p4d_addr_end
#define p4d_addr_end(addr, end) (end)
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 5e0c2d01e656..05dddc17522b 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -594,7 +594,6 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
} while (0)
#endif
-#ifndef __ARCH_HAS_5LEVEL_HACK
#ifndef p4d_free_tlb
#define p4d_free_tlb(tlb, pudp, address) \
do { \
@@ -603,7 +602,6 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
__p4d_free_tlb(tlb, pudp, address); \
} while (0)
#endif
-#endif
#endif /* CONFIG_MMU */
--
2.20.1
... independent of __ARCH_HAS_4LEVEL_HACK
This came up when removing __ARCH_HAS_5LEVEL_HACK for ARC as code bloat.
With this patch we see the following code reduction
| bloat-o-meter2 vmlinux-B-elide-ARCH_USE_5LEVEL_HACK vmlinux-C-elide-pud_free_tlb
| add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-104 (-104)
| function old new delta
| free_pgd_range 656 552 -104
| Total: Before=4137276, After=4137172, chg -1.000000%
Note: The primary change is alternate defintion for pud_free_tlb() but
while there also removed empty stubs for __pud_free_tlb, which is anyhow
called only from pud_free_tlb()
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Linus Torvalds <[email protected]>
Signed-off-by: Vineet Gupta <[email protected]>
---
include/asm-generic/4level-fixup.h | 1 -
include/asm-generic/pgtable-nopud.h | 2 +-
include/asm-generic/tlb.h | 2 --
3 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/include/asm-generic/4level-fixup.h b/include/asm-generic/4level-fixup.h
index e3667c9a33a5..c86cf7cb4bba 100644
--- a/include/asm-generic/4level-fixup.h
+++ b/include/asm-generic/4level-fixup.h
@@ -30,7 +30,6 @@
#undef pud_free_tlb
#define pud_free_tlb(tlb, x, addr) do { } while (0)
#define pud_free(mm, x) do { } while (0)
-#define __pud_free_tlb(tlb, x, addr) do { } while (0)
#undef pud_addr_end
#define pud_addr_end(addr, end) (end)
diff --git a/include/asm-generic/pgtable-nopud.h b/include/asm-generic/pgtable-nopud.h
index c77a1d301155..d3776cb494c0 100644
--- a/include/asm-generic/pgtable-nopud.h
+++ b/include/asm-generic/pgtable-nopud.h
@@ -59,7 +59,7 @@ static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
*/
#define pud_alloc_one(mm, address) NULL
#define pud_free(mm, x) do { } while (0)
-#define __pud_free_tlb(tlb, x, a) do { } while (0)
+#define pud_free_tlb(tlb, x, a) do { } while (0)
#undef pud_addr_end
#define pud_addr_end(addr, end) (end)
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 04c0644006fd..5e0c2d01e656 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -584,7 +584,6 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
} while (0)
#endif
-#ifndef __ARCH_HAS_4LEVEL_HACK
#ifndef pud_free_tlb
#define pud_free_tlb(tlb, pudp, address) \
do { \
@@ -594,7 +593,6 @@ static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vm
__pud_free_tlb(tlb, pudp, address); \
} while (0)
#endif
-#endif
#ifndef __ARCH_HAS_5LEVEL_HACK
#ifndef p4d_free_tlb
--
2.20.1