The patch titled
Subject: mm/hugetlb: reduce arch dependent code around follow_huge_*
has been added to the -mm tree. Its filename is
mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Subject: mm/hugetlb: reduce arch dependent code around follow_huge_*
Currently we have many duplicates in definitions around
follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this
patch tries to remove them. The basic idea is to put the default
implementation for these functions in mm/hugetlb.c as weak symbols
(regardless of CONFIG_ARCH_WANT_GENERAL_HUGETLB), and to implement
arch-specific code only when the arch needs it.
For follow_huge_addr(), only powerpc and ia64 have their own
implementation, and in all other architectures this function just returns
ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as
default.
As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to
always return 0 in your architecture (like in ia64 or sparc,) it's never
called (the callsite is optimized away) no matter how implemented it is.
So in such architectures, we don't need arch-specific implementation.
In some architecture (like mips, s390 and tile,) their current
arch-specific follow_huge_(pmd|pud)() are effectively identical with the
common code, so this patch lets these architecture use the common code.
One exception is metag, where pmd_huge() could return non-zero but it
expects follow_huge_pmd() to always return NULL. This means that we need
arch-specific implementation which returns NULL. This behavior looks
strange to me (because non-zero pmd_huge() implies that the architecture
supports PMD-based hugepage, so follow_huge_pmd() can/should return some
relevant value,) but that's beyond this cleanup patch, so let's keep it.
Justification of non-trivial changes:
- in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this
patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE
is true when follow_huge_pmd() can be called (note that pmd_huge() has
the same check and always returns 0 for !MACHINE_HAS_HPAGE.)
- in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common
code. This patch forces these archs use PMD_MASK, but it's OK because
they are identical in both archs.
In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20.
In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and
PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but
PTE_ORDER is always 0, so these are identical.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/arm/mm/hugetlbpage.c | 6 ------
arch/arm64/mm/hugetlbpage.c | 6 ------
arch/ia64/mm/hugetlbpage.c | 6 ------
arch/metag/mm/hugetlbpage.c | 6 ------
arch/mips/mm/hugetlbpage.c | 18 ------------------
arch/powerpc/mm/hugetlbpage.c | 8 ++++++++
arch/s390/mm/hugetlbpage.c | 20 --------------------
arch/sh/mm/hugetlbpage.c | 12 ------------
arch/sparc/mm/hugetlbpage.c | 12 ------------
arch/tile/mm/hugetlbpage.c | 28 ----------------------------
arch/x86/mm/hugetlbpage.c | 12 ------------
mm/hugetlb.c | 30 +++++++++++++++---------------
12 files changed, 23 insertions(+), 141 deletions(-)
diff -puN arch/arm/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/arm/mm/hugetlbpage.c
--- a/arch/arm/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/arm/mm/hugetlbpage.c
@@ -36,12 +36,6 @@
* of type casting from pmd_t * to pte_t *.
*/
-struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
- int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pud_huge(pud_t pud)
{
return 0;
diff -puN arch/arm64/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/arm64/mm/hugetlbpage.c
--- a/arch/arm64/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/arm64/mm/hugetlbpage.c
@@ -38,12 +38,6 @@ int huge_pmd_unshare(struct mm_struct *m
}
#endif
-struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
- int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return !(pmd_val(pmd) & PMD_TABLE_BIT);
diff -puN arch/ia64/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/ia64/mm/hugetlbpage.c
--- a/arch/ia64/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/ia64/mm/hugetlbpage.c
@@ -114,12 +114,6 @@ int pud_huge(pud_t pud)
return 0;
}
-struct page *
-follow_huge_pmd(struct mm_struct *mm, unsigned long address, pmd_t *pmd, int write)
-{
- return NULL;
-}
-
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
diff -puN arch/metag/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/metag/mm/hugetlbpage.c
--- a/arch/metag/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/metag/mm/hugetlbpage.c
@@ -94,12 +94,6 @@ int huge_pmd_unshare(struct mm_struct *m
return 0;
}
-struct page *follow_huge_addr(struct mm_struct *mm,
- unsigned long address, int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return pmd_page_shift(pmd) > PAGE_SHIFT;
diff -puN arch/mips/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/mips/mm/hugetlbpage.c
--- a/arch/mips/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/mips/mm/hugetlbpage.c
@@ -68,12 +68,6 @@ int is_aligned_hugepage_range(unsigned l
return 0;
}
-struct page *
-follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return (pmd_val(pmd) & _PAGE_HUGE) != 0;
@@ -83,15 +77,3 @@ int pud_huge(pud_t pud)
{
return (pud_val(pud) & _PAGE_HUGE) != 0;
}
-
-struct page *
-follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- struct page *page;
-
- page = pte_page(*(pte_t *)pmd);
- if (page)
- page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
- return page;
-}
diff -puN arch/powerpc/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/powerpc/mm/hugetlbpage.c
--- a/arch/powerpc/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/powerpc/mm/hugetlbpage.c
@@ -706,6 +706,14 @@ follow_huge_pmd(struct mm_struct *mm, un
return NULL;
}
+struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd, int write)
+{
+ BUG();
+ return NULL;
+}
+
static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
unsigned long sz)
{
diff -puN arch/s390/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/s390/mm/hugetlbpage.c
--- a/arch/s390/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/s390/mm/hugetlbpage.c
@@ -192,12 +192,6 @@ int huge_pmd_unshare(struct mm_struct *m
return 0;
}
-struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
- int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
if (!MACHINE_HAS_HPAGE)
@@ -210,17 +204,3 @@ int pud_huge(pud_t pud)
{
return 0;
}
-
-struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmdp, int write)
-{
- struct page *page;
-
- if (!MACHINE_HAS_HPAGE)
- return NULL;
-
- page = pmd_page(*pmdp);
- if (page)
- page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
- return page;
-}
diff -puN arch/sh/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/sh/mm/hugetlbpage.c
--- a/arch/sh/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/sh/mm/hugetlbpage.c
@@ -67,12 +67,6 @@ int huge_pmd_unshare(struct mm_struct *m
return 0;
}
-struct page *follow_huge_addr(struct mm_struct *mm,
- unsigned long address, int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return 0;
@@ -82,9 +76,3 @@ int pud_huge(pud_t pud)
{
return 0;
}
-
-struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- return NULL;
-}
diff -puN arch/sparc/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/sparc/mm/hugetlbpage.c
--- a/arch/sparc/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/sparc/mm/hugetlbpage.c
@@ -215,12 +215,6 @@ pte_t huge_ptep_get_and_clear(struct mm_
return entry;
}
-struct page *follow_huge_addr(struct mm_struct *mm,
- unsigned long address, int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return 0;
@@ -230,9 +224,3 @@ int pud_huge(pud_t pud)
{
return 0;
}
-
-struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- return NULL;
-}
diff -puN arch/tile/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/tile/mm/hugetlbpage.c
--- a/arch/tile/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/tile/mm/hugetlbpage.c
@@ -150,12 +150,6 @@ pte_t *huge_pte_offset(struct mm_struct
return NULL;
}
-struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
- int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_HUGE_PAGE);
@@ -166,28 +160,6 @@ int pud_huge(pud_t pud)
return !!(pud_val(pud) & _PAGE_HUGE_PAGE);
}
-struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- struct page *page;
-
- page = pte_page(*(pte_t *)pmd);
- if (page)
- page += ((address & ~PMD_MASK) >> PAGE_SHIFT);
- return page;
-}
-
-struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
- pud_t *pud, int write)
-{
- struct page *page;
-
- page = pte_page(*(pte_t *)pud);
- if (page)
- page += ((address & ~PUD_MASK) >> PAGE_SHIFT);
- return page;
-}
-
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
{
return 0;
diff -puN arch/x86/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ arch/x86/mm/hugetlbpage.c
--- a/arch/x86/mm/hugetlbpage.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/arch/x86/mm/hugetlbpage.c
@@ -52,20 +52,8 @@ int pud_huge(pud_t pud)
return 0;
}
-struct page *
-follow_huge_pmd(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd, int write)
-{
- return NULL;
-}
#else
-struct page *
-follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
-{
- return ERR_PTR(-EINVAL);
-}
-
int pmd_huge(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_PSE);
diff -puN mm/hugetlb.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_ mm/hugetlb.c
--- a/mm/hugetlb.c~mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_
+++ a/mm/hugetlb.c
@@ -3653,7 +3653,20 @@ pte_t *huge_pte_offset(struct mm_struct
return (pte_t *) pmd;
}
-struct page *
+#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
+
+/*
+ * These functions are overwritable if your architecture needs its own
+ * behavior.
+ */
+struct page * __weak
+follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+struct page * __weak
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
pmd_t *pmd, int write)
{
@@ -3665,7 +3678,7 @@ follow_huge_pmd(struct mm_struct *mm, un
return page;
}
-struct page *
+struct page * __weak
follow_huge_pud(struct mm_struct *mm, unsigned long address,
pud_t *pud, int write)
{
@@ -3677,19 +3690,6 @@ follow_huge_pud(struct mm_struct *mm, un
return page;
}
-#else /* !CONFIG_ARCH_WANT_GENERAL_HUGETLB */
-
-/* Can be overriden by architectures */
-struct page * __weak
-follow_huge_pud(struct mm_struct *mm, unsigned long address,
- pud_t *pud, int write)
-{
- BUG();
- return NULL;
-}
-
-#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
-
#ifdef CONFIG_MEMORY_FAILURE
/* Should be called in hugetlb_lock */
_
Patches currently in -mm which might be from n-horiguchi@xxxxxxxxxxxxx are
mm-softdirty-addresses-before-vmas-in-pte-holes-arent-softdirty.patch
memory-hotplug-add-sysfs-zones_online_to-attribute.patch
memory-hotplug-add-sysfs-zones_online_to-attribute-fix-3.patch
memory-hotplug-add-sysfs-zones_online_to-attribute-fix-4.patch
mm-thp-dont-hold-mmap_sem-in-khugepaged-when-allocating-thp.patch
mm-compaction-defer-each-zone-individually-instead-of-preferred-zone.patch
mm-compaction-defer-each-zone-individually-instead-of-preferred-zone-fix.patch
mm-compaction-do-not-count-compact_stall-if-all-zones-skipped-compaction.patch
mm-compaction-do-not-recheck-suitable_migration_target-under-lock.patch
mm-compaction-move-pageblock-checks-up-from-isolate_migratepages_range.patch
mm-compaction-reduce-zone-checking-frequency-in-the-migration-scanner.patch
mm-compaction-khugepaged-should-not-give-up-due-to-need_resched.patch
mm-compaction-khugepaged-should-not-give-up-due-to-need_resched-fix.patch
mm-compaction-periodically-drop-lock-and-restore-irqs-in-scanners.patch
mm-compaction-skip-rechecks-when-lock-was-already-held.patch
mm-compaction-remember-position-within-pageblock-in-free-pages-scanner.patch
mm-compaction-skip-buddy-pages-by-their-order-in-the-migrate-scanner.patch
mm-rename-allocflags_to_migratetype-for-clarity.patch
mm-compaction-pass-gfp-mask-to-compact_control.patch
mempolicy-change-alloc_pages_vma-to-use-mpol_cond_put.patch
mempolicy-change-get_task_policy-to-return-default_policy-rather-than-null.patch
mempolicy-sanitize-the-usage-of-get_task_policy.patch
mempolicy-remove-the-task-arg-of-vma_policy_mof-and-simplify-it.patch
mempolicy-introduce-__get_vma_policy-export-get_task_policy.patch
mempolicy-fix-show_numa_map-vs-exec-do_set_mempolicy-race.patch
mempolicy-kill-do_set_mempolicy-down_writemm-mmap_sem.patch
mempolicy-unexport-get_vma_policy-and-remove-its-task-arg.patch
introduce-dump_vma.patch
introduce-dump_vma-fix.patch
introduce-vm_bug_on_vma.patch
convert-a-few-vm_bug_on-callers-to-vm_bug_on_vma.patch
mm-softdirty-enable-write-notifications-on-vmas-after-vm_softdirty-cleared.patch
mm-softdirty-unmapped-addresses-between-vmas-are-clean.patch
mm-hugetlb-reduce-arch-dependent-code-around-follow_huge_.patch
mm-hugetlb-take-page-table-lock-in-follow_huge_pmd.patch
mm-hugetlb-fix-getting-refcount-0-page-in-hugetlb_fault.patch
mm-hugetlb-add-migration-hwpoisoned-entry-check-in-hugetlb_change_protection.patch
mm-hugetlb-add-migration-entry-check-in-__unmap_hugepage_range.patch
mm-introduce-do_shared_fault-and-drop-do_fault-fix-fix.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
