+ mm-functions-may-simplify-the-use-of-return-values.patch added to mm-unstable branch

* + mm-functions-may-simplify-the-use-of-return-values.patch added to mm-unstable branch
@ 2022-05-07 17:50 Andrew Morton
  2022-05-09  7:20 ` Peter Zijlstra
  0 siblings, 1 reply; 3+ messages in thread
From: Andrew Morton @ 2022-05-07 17:50 UTC (permalink / raw)
  To: mm-commits, tglx, peterz, mingo, luto, hpa, dave.hansen, bp, kunyu, akpm


The patch titled
     Subject: mm: functions may simplify the use of return values
has been added to the -mm mm-unstable branch.  Its filename is
     mm-functions-may-simplify-the-use-of-return-values.patch

This patch should soon appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Li kunyu <kunyu@nfschina.com>
Subject: mm: functions may simplify the use of return values

p4d_clear_huge may be optimized for void return type and function usage. 
vunmap_p4d_range function saves a few steps here.

Link: https://lkml.kernel.org/r/20220507150630.90399-1-kunyu@nfschina.com
Signed-off-by: Li kunyu <kunyu@nfschina.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/mm/pgtable.c   |    3 +--
 include/linux/pgtable.h |   12 +++---------
 mm/vmalloc.c            |    7 ++-----
 3 files changed, 6 insertions(+), 16 deletions(-)

--- a/arch/x86/mm/pgtable.c~mm-functions-may-simplify-the-use-of-return-values
+++ a/arch/x86/mm/pgtable.c
@@ -686,9 +686,8 @@ int p4d_set_huge(p4d_t *p4d, phys_addr_t
  *
  * No 512GB pages yet -- always return 0
  */
-int p4d_clear_huge(p4d_t *p4d)
+void p4d_clear_huge(p4d_t *p4d)
 {
-	return 0;
 }
 #endif
 
--- a/include/linux/pgtable.h~mm-functions-may-simplify-the-use-of-return-values
+++ a/include/linux/pgtable.h
@@ -1443,16 +1443,13 @@ static inline int pmd_protnone(pmd_t pmd
 
 #ifndef __PAGETABLE_P4D_FOLDED
 int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
-int p4d_clear_huge(p4d_t *p4d);
+void p4d_clear_huge(p4d_t *p4d);
 #else
 static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
 {
 	return 0;
 }
-static inline int p4d_clear_huge(p4d_t *p4d)
-{
-	return 0;
-}
+static inline void p4d_clear_huge(p4d_t *p4d) { }
 #endif /* !__PAGETABLE_P4D_FOLDED */
 
 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
@@ -1475,10 +1472,7 @@ static inline int pmd_set_huge(pmd_t *pm
 {
 	return 0;
 }
-static inline int p4d_clear_huge(p4d_t *p4d)
-{
-	return 0;
-}
+static inline void p4d_clear_huge(p4d_t *p4d) { }
 static inline int pud_clear_huge(pud_t *pud)
 {
 	return 0;
--- a/mm/vmalloc.c~mm-functions-may-simplify-the-use-of-return-values
+++ a/mm/vmalloc.c
@@ -389,18 +389,15 @@ static void vunmap_p4d_range(pgd_t *pgd,
 {
 	p4d_t *p4d;
 	unsigned long next;
-	int cleared;
 
 	p4d = p4d_offset(pgd, addr);
 	do {
 		next = p4d_addr_end(addr, end);
 
-		cleared = p4d_clear_huge(p4d);
-		if (cleared || p4d_bad(*p4d))
+		p4d_clear_huge(p4d);
+		if (p4d_bad(*p4d))
 			*mask |= PGTBL_P4D_MODIFIED;
 
-		if (cleared)
-			continue;
 		if (p4d_none_or_clear_bad(p4d))
 			continue;
 		vunmap_pud_range(p4d, addr, next, mask);
_

Patches currently in -mm which might be from kunyu@nfschina.com are

mm-functions-may-simplify-the-use-of-return-values.patch


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