[PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[David Hildenbrand]

Some cleanups around function names, comments and the config option of
"GUP-fast" -- GUP without "lock" safety belts on.

With this cleanup it's easy to judge which functions are GUP-fast specific.
We now consistently call it "GUP-fast", avoiding mixing it with "fast GUP",
"lockless", or simply "gup" (which I always considered confusing in the
ode).

So the magic now happens in functions that contain "gup_fast", whereby
gup_fast() is the entry point into that magic. Comments consistently
reference either "GUP-fast" or "gup_fast()".

Based on mm-unstable from today. I won't CC arch maintainers, but only
arch mailing lists, to reduce noise.

Tested on x86_64, cross compiled on a bunch of archs, whereby some of them
don't properly even compile on mm-unstable anymore in my usual setup
(alpha, arc, parisc64, sh) ... maybe the cross compilers are outdated,
but there are no new ones around. Hm.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: loongarch@lists.linux.dev
Cc: linux-mips@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-perf-users@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: x86@kernel.org

David Hildenbrand (3):
  mm/gup: consistently name GUP-fast functions
  mm/treewide: rename CONFIG_HAVE_FAST_GUP to CONFIG_HAVE_GUP_FAST
  mm: use "GUP-fast" instead "fast GUP" in remaining comments

 arch/arm/Kconfig       |   2 +-
 arch/arm64/Kconfig     |   2 +-
 arch/loongarch/Kconfig |   2 +-
 arch/mips/Kconfig      |   2 +-
 arch/powerpc/Kconfig   |   2 +-
 arch/s390/Kconfig      |   2 +-
 arch/sh/Kconfig        |   2 +-
 arch/x86/Kconfig       |   2 +-
 include/linux/rmap.h   |   8 +-
 kernel/events/core.c   |   4 +-
 mm/Kconfig             |   2 +-
 mm/filemap.c           |   2 +-
 mm/gup.c               | 170 +++++++++++++++++++++--------------------
 mm/internal.h          |   2 +-
 mm/khugepaged.c        |   2 +-
 15 files changed, 105 insertions(+), 101 deletions(-)

-- 
2.43.2

[PATCH RFC 1/3] mm/gup: consistently name GUP-fast functions

[David Hildenbrand]

Let's consistently call the "fast-only" part of GUP "GUP-fast" and rename
all relevant internal functions to start with "gup_fast", to make it
clearer that this is not ordinary GUP. The current mixture of
"lockless", "gup" and "gup_fast" is confusing.

Further, avoid the term "huge" when talking about a "leaf" -- for
example, we nowadays check pmd_leaf() because pmd_huge() is gone. For the
"hugepd"/"hugepte" stuff, it's part of the name ("is_hugepd"), so that
says.

What remains is the "external" interface:
* get_user_pages_fast_only()
* get_user_pages_fast()
* pin_user_pages_fast()

And the "internal" interface that handles GUP-fast + fallback:
* internal_get_user_pages_fast()

The high-level internal function for GUP-fast is now:
* gup_fast()

The basic GUP-fast walker functions:
* gup_pgd_range() -> gup_fast_pgd_range()
* gup_p4d_range() -> gup_fast_p4d_range()
* gup_pud_range() -> gup_fast_pud_range()
* gup_pmd_range() -> gup_fast_pmd_range()
* gup_pte_range() -> gup_fast_pte_range()
* gup_huge_pgd()  -> gup_fast_pgd_leaf()
* gup_huge_pud()  -> gup_fast_pud_leaf()
* gup_huge_pmd()  -> gup_fast_pmd_leaf()

The weird hugepd stuff:
* gup_huge_pd() -> gup_fast_hugepd()
* gup_hugepte() -> gup_fast_hugepte()

The weird devmap stuff:
* __gup_device_huge_pud() -> gup_fast_devmap_pud_leaf()
* __gup_device_huge_pmd   -> gup_fast_devmap_pmd_leaf()
* __gup_device_huge()     -> gup_fast_devmap_leaf()

Helper functions:
* unpin_user_pages_lockless() -> gup_fast_unpin_user_pages()
* gup_fast_folio_allowed() is already properly named
* gup_fast_permitted() is already properly named

With "gup_fast()", we now even have a function that is referred to in
comment in mm/mmu_gather.c.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/gup.c | 164 ++++++++++++++++++++++++++++---------------------------
 1 file changed, 84 insertions(+), 80 deletions(-)

diff --git a/mm/gup.c b/mm/gup.c
index 03b74b148e30..c293aff30c5d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -440,7 +440,7 @@ void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
 }
 EXPORT_SYMBOL(unpin_user_page_range_dirty_lock);
 
-static void unpin_user_pages_lockless(struct page **pages, unsigned long npages)
+static void gup_fast_unpin_user_pages(struct page **pages, unsigned long npages)
 {
 	unsigned long i;
 	struct folio *folio;
@@ -2431,7 +2431,7 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
 EXPORT_SYMBOL(get_user_pages_unlocked);
 
 /*
- * Fast GUP
+ * GUP-fast
  *
  * get_user_pages_fast attempts to pin user pages by walking the page
  * tables directly and avoids taking locks. Thus the walker needs to be
@@ -2445,7 +2445,7 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
  *
  * Another way to achieve this is to batch up page table containing pages
  * belonging to more than one mm_user, then rcu_sched a callback to free those
- * pages. Disabling interrupts will allow the fast_gup walker to both block
+ * pages. Disabling interrupts will allow the gup_fast() walker to both block
  * the rcu_sched callback, and an IPI that we broadcast for splitting THPs
  * (which is a relatively rare event). The code below adopts this strategy.
  *
@@ -2589,9 +2589,9 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
  * also check pmd here to make sure pmd doesn't change (corresponds to
  * pmdp_collapse_flush() in the THP collapse code path).
  */
-static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
-			 unsigned long end, unsigned int flags,
-			 struct page **pages, int *nr)
+static int gup_fast_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	struct dev_pagemap *pgmap = NULL;
 	int nr_start = *nr, ret = 0;
@@ -2688,20 +2688,19 @@ static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
  *
  * For a futex to be placed on a THP tail page, get_futex_key requires a
  * get_user_pages_fast_only implementation that can pin pages. Thus it's still
- * useful to have gup_huge_pmd even if we can't operate on ptes.
+ * useful to have gup_fast_pmd_leaf even if we can't operate on ptes.
  */
-static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
-			 unsigned long end, unsigned int flags,
-			 struct page **pages, int *nr)
+static int gup_fast_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	return 0;
 }
 #endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
 #if defined(CONFIG_ARCH_HAS_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
-static int __gup_device_huge(unsigned long pfn, unsigned long addr,
-			     unsigned long end, unsigned int flags,
-			     struct page **pages, int *nr)
+static int gup_fast_devmap_leaf(unsigned long pfn, unsigned long addr,
+	unsigned long end, unsigned int flags, struct page **pages, int *nr)
 {
 	int nr_start = *nr;
 	struct dev_pagemap *pgmap = NULL;
@@ -2734,15 +2733,15 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
 	return addr == end;
 }
 
-static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
-				 unsigned long end, unsigned int flags,
-				 struct page **pages, int *nr)
+static int gup_fast_devmap_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long fault_pfn;
 	int nr_start = *nr;
 
 	fault_pfn = pmd_pfn(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
-	if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr))
+	if (!gup_fast_devmap_leaf(fault_pfn, addr, end, flags, pages, nr))
 		return 0;
 
 	if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) {
@@ -2752,15 +2751,15 @@ static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
 	return 1;
 }
 
-static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
-				 unsigned long end, unsigned int flags,
-				 struct page **pages, int *nr)
+static int gup_fast_devmap_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long fault_pfn;
 	int nr_start = *nr;
 
 	fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
-	if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr))
+	if (!gup_fast_devmap_leaf(fault_pfn, addr, end, flags, pages, nr))
 		return 0;
 
 	if (unlikely(pud_val(orig) != pud_val(*pudp))) {
@@ -2770,17 +2769,17 @@ static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
 	return 1;
 }
 #else
-static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
-				 unsigned long end, unsigned int flags,
-				 struct page **pages, int *nr)
+static int gup_fast_devmap_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	BUILD_BUG();
 	return 0;
 }
 
-static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr,
-				 unsigned long end, unsigned int flags,
-				 struct page **pages, int *nr)
+static int gup_fast_devmap_pud_leaf(pud_t pud, pud_t *pudp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	BUILD_BUG();
 	return 0;
@@ -2806,9 +2805,9 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
 	return (__boundary - 1 < end - 1) ? __boundary : end;
 }
 
-static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
-		       unsigned long end, unsigned int flags,
-		       struct page **pages, int *nr)
+static int gup_fast_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long pte_end;
 	struct page *page;
@@ -2855,7 +2854,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
 	return 1;
 }
 
-static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
+static int gup_fast_hugepd(hugepd_t hugepd, unsigned long addr,
 		unsigned int pdshift, unsigned long end, unsigned int flags,
 		struct page **pages, int *nr)
 {
@@ -2866,14 +2865,14 @@ static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
 	ptep = hugepte_offset(hugepd, addr, pdshift);
 	do {
 		next = hugepte_addr_end(addr, end, sz);
-		if (!gup_hugepte(ptep, sz, addr, end, flags, pages, nr))
+		if (!gup_fast_hugepte(ptep, sz, addr, end, flags, pages, nr))
 			return 0;
 	} while (ptep++, addr = next, addr != end);
 
 	return 1;
 }
 #else
-static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
+static inline int gup_fast_hugepd(hugepd_t hugepd, unsigned long addr,
 		unsigned int pdshift, unsigned long end, unsigned int flags,
 		struct page **pages, int *nr)
 {
@@ -2881,9 +2880,9 @@ static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
 }
 #endif /* CONFIG_ARCH_HAS_HUGEPD */
 
-static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
-			unsigned long end, unsigned int flags,
-			struct page **pages, int *nr)
+static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	struct page *page;
 	struct folio *folio;
@@ -2895,8 +2894,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
 	if (pmd_devmap(orig)) {
 		if (unlikely(flags & FOLL_LONGTERM))
 			return 0;
-		return __gup_device_huge_pmd(orig, pmdp, addr, end, flags,
-					     pages, nr);
+		return gup_fast_devmap_pmd_leaf(orig, pmdp, addr, end, flags,
+					        pages, nr);
 	}
 
 	page = nth_page(pmd_page(orig), (addr & ~PMD_MASK) >> PAGE_SHIFT);
@@ -2925,9 +2924,9 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
 	return 1;
 }
 
-static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
-			unsigned long end, unsigned int flags,
-			struct page **pages, int *nr)
+static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	struct page *page;
 	struct folio *folio;
@@ -2939,8 +2938,8 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
 	if (pud_devmap(orig)) {
 		if (unlikely(flags & FOLL_LONGTERM))
 			return 0;
-		return __gup_device_huge_pud(orig, pudp, addr, end, flags,
-					     pages, nr);
+		return gup_fast_devmap_pud_leaf(orig, pudp, addr, end, flags,
+					        pages, nr);
 	}
 
 	page = nth_page(pud_page(orig), (addr & ~PUD_MASK) >> PAGE_SHIFT);
@@ -2970,9 +2969,9 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
 	return 1;
 }
 
-static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
-			unsigned long end, unsigned int flags,
-			struct page **pages, int *nr)
+static int gup_fast_pgd_leaf(pgd_t orig, pgd_t *pgdp, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	int refs;
 	struct page *page;
@@ -3010,8 +3009,9 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
 	return 1;
 }
 
-static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned long end,
-		unsigned int flags, struct page **pages, int *nr)
+static int gup_fast_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long next;
 	pmd_t *pmdp;
@@ -3025,11 +3025,11 @@ static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned lo
 			return 0;
 
 		if (unlikely(pmd_leaf(pmd))) {
-			/* See gup_pte_range() */
+			/* See gup_fast_pte_range() */
 			if (pmd_protnone(pmd))
 				return 0;
 
-			if (!gup_huge_pmd(pmd, pmdp, addr, next, flags,
+			if (!gup_fast_pmd_leaf(pmd, pmdp, addr, next, flags,
 				pages, nr))
 				return 0;
 
@@ -3038,18 +3038,20 @@ static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned lo
 			 * architecture have different format for hugetlbfs
 			 * pmd format and THP pmd format
 			 */
-			if (!gup_huge_pd(__hugepd(pmd_val(pmd)), addr,
-					 PMD_SHIFT, next, flags, pages, nr))
+			if (!gup_fast_hugepd(__hugepd(pmd_val(pmd)), addr,
+					     PMD_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pte_range(pmd, pmdp, addr, next, flags, pages, nr))
+		} else if (!gup_fast_pte_range(pmd, pmdp, addr, next, flags,
+					       pages, nr))
 			return 0;
 	} while (pmdp++, addr = next, addr != end);
 
 	return 1;
 }
 
-static int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, unsigned long end,
-			 unsigned int flags, struct page **pages, int *nr)
+static int gup_fast_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long next;
 	pud_t *pudp;
@@ -3062,22 +3064,24 @@ static int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, unsigned lo
 		if (unlikely(!pud_present(pud)))
 			return 0;
 		if (unlikely(pud_leaf(pud))) {
-			if (!gup_huge_pud(pud, pudp, addr, next, flags,
-					  pages, nr))
+			if (!gup_fast_pud_leaf(pud, pudp, addr, next, flags,
+					       pages, nr))
 				return 0;
 		} else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) {
-			if (!gup_huge_pd(__hugepd(pud_val(pud)), addr,
-					 PUD_SHIFT, next, flags, pages, nr))
+			if (!gup_fast_hugepd(__hugepd(pud_val(pud)), addr,
+					     PUD_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pmd_range(pudp, pud, addr, next, flags, pages, nr))
+		} else if (!gup_fast_pmd_range(pudp, pud, addr, next, flags,
+					       pages, nr))
 			return 0;
 	} while (pudp++, addr = next, addr != end);
 
 	return 1;
 }
 
-static int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, unsigned long end,
-			 unsigned int flags, struct page **pages, int *nr)
+static int gup_fast_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
+		unsigned long end, unsigned int flags, struct page **pages,
+		int *nr)
 {
 	unsigned long next;
 	p4d_t *p4dp;
@@ -3091,17 +3095,18 @@ static int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, unsigned lo
 			return 0;
 		BUILD_BUG_ON(p4d_leaf(p4d));
 		if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
-			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
-					 P4D_SHIFT, next, flags, pages, nr))
+			if (!gup_fast_hugepd(__hugepd(p4d_val(p4d)), addr,
+					     P4D_SHIFT, next, flags, pages, nr))
 				return 0;
-		} else if (!gup_pud_range(p4dp, p4d, addr, next, flags, pages, nr))
+		} else if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
+					       pages, nr))
 			return 0;
 	} while (p4dp++, addr = next, addr != end);
 
 	return 1;
 }
 
-static void gup_pgd_range(unsigned long addr, unsigned long end,
+static void gup_fast_pgd_range(unsigned long addr, unsigned long end,
 		unsigned int flags, struct page **pages, int *nr)
 {
 	unsigned long next;
@@ -3115,19 +3120,20 @@ static void gup_pgd_range(unsigned long addr, unsigned long end,
 		if (pgd_none(pgd))
 			return;
 		if (unlikely(pgd_leaf(pgd))) {
-			if (!gup_huge_pgd(pgd, pgdp, addr, next, flags,
-					  pages, nr))
+			if (!gup_fast_pgd_leaf(pgd, pgdp, addr, next, flags,
+					       pages, nr))
 				return;
 		} else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) {
-			if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
-					 PGDIR_SHIFT, next, flags, pages, nr))
+			if (!gup_fast_hugepd(__hugepd(pgd_val(pgd)), addr,
+					      PGDIR_SHIFT, next, flags, pages, nr))
 				return;
-		} else if (!gup_p4d_range(pgdp, pgd, addr, next, flags, pages, nr))
+		} else if (!gup_fast_p4d_range(pgdp, pgd, addr, next, flags,
+					       pages, nr))
 			return;
 	} while (pgdp++, addr = next, addr != end);
 }
 #else
-static inline void gup_pgd_range(unsigned long addr, unsigned long end,
+static inline void gup_fast_pgd_range(unsigned long addr, unsigned long end,
 		unsigned int flags, struct page **pages, int *nr)
 {
 }
@@ -3144,10 +3150,8 @@ static bool gup_fast_permitted(unsigned long start, unsigned long end)
 }
 #endif
 
-static unsigned long lockless_pages_from_mm(unsigned long start,
-					    unsigned long end,
-					    unsigned int gup_flags,
-					    struct page **pages)
+static unsigned long gup_fast(unsigned long start, unsigned long end,
+		unsigned int gup_flags, struct page **pages)
 {
 	unsigned long flags;
 	int nr_pinned = 0;
@@ -3175,16 +3179,16 @@ static unsigned long lockless_pages_from_mm(unsigned long start,
 	 * that come from THPs splitting.
 	 */
 	local_irq_save(flags);
-	gup_pgd_range(start, end, gup_flags, pages, &nr_pinned);
+	gup_fast_pgd_range(start, end, gup_flags, pages, &nr_pinned);
 	local_irq_restore(flags);
 
 	/*
 	 * When pinning pages for DMA there could be a concurrent write protect
-	 * from fork() via copy_page_range(), in this case always fail fast GUP.
+	 * from fork() via copy_page_range(), in this case always fail GUP-fast.
 	 */
 	if (gup_flags & FOLL_PIN) {
 		if (read_seqcount_retry(&current->mm->write_protect_seq, seq)) {
-			unpin_user_pages_lockless(pages, nr_pinned);
+			gup_fast_unpin_user_pages(pages, nr_pinned);
 			return 0;
 		} else {
 			sanity_check_pinned_pages(pages, nr_pinned);
@@ -3224,7 +3228,7 @@ static int internal_get_user_pages_fast(unsigned long start,
 	if (unlikely(!access_ok((void __user *)start, len)))
 		return -EFAULT;
 
-	nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
+	nr_pinned = gup_fast(start, end, gup_flags, pages);
 	if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
 		return nr_pinned;
 
-- 
2.43.2

Re: [PATCH RFC 1/3] mm/gup: consistently name GUP-fast functions

[Jason Gunthorpe]

On Wed, Mar 27, 2024 at 02:05:36PM +0100, David Hildenbrand wrote:
> Let's consistently call the "fast-only" part of GUP "GUP-fast" and rename
> all relevant internal functions to start with "gup_fast", to make it
> clearer that this is not ordinary GUP. The current mixture of
> "lockless", "gup" and "gup_fast" is confusing.
> 
> Further, avoid the term "huge" when talking about a "leaf" -- for
> example, we nowadays check pmd_leaf() because pmd_huge() is gone. For the
> "hugepd"/"hugepte" stuff, it's part of the name ("is_hugepd"), so that
> says.
> 
> What remains is the "external" interface:
> * get_user_pages_fast_only()
> * get_user_pages_fast()
> * pin_user_pages_fast()
> 
> And the "internal" interface that handles GUP-fast + fallback:
> * internal_get_user_pages_fast()

This would like a better name too. How about gup_fast_fallback() ?

> The high-level internal function for GUP-fast is now:
> * gup_fast()
> 
> The basic GUP-fast walker functions:
> * gup_pgd_range() -> gup_fast_pgd_range()
> * gup_p4d_range() -> gup_fast_p4d_range()
> * gup_pud_range() -> gup_fast_pud_range()
> * gup_pmd_range() -> gup_fast_pmd_range()
> * gup_pte_range() -> gup_fast_pte_range()
> * gup_huge_pgd()  -> gup_fast_pgd_leaf()
> * gup_huge_pud()  -> gup_fast_pud_leaf()
> * gup_huge_pmd()  -> gup_fast_pmd_leaf()
> 
> The weird hugepd stuff:
> * gup_huge_pd() -> gup_fast_hugepd()
> * gup_hugepte() -> gup_fast_hugepte()
> 
> The weird devmap stuff:
> * __gup_device_huge_pud() -> gup_fast_devmap_pud_leaf()
> * __gup_device_huge_pmd   -> gup_fast_devmap_pmd_leaf()
> * __gup_device_huge()     -> gup_fast_devmap_leaf()
>
> Helper functions:
> * unpin_user_pages_lockless() -> gup_fast_unpin_user_pages()
> * gup_fast_folio_allowed() is already properly named
> * gup_fast_permitted() is already properly named
> 
> With "gup_fast()", we now even have a function that is referred to in
> comment in mm/mmu_gather.c.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---
>  mm/gup.c | 164 ++++++++++++++++++++++++++++---------------------------
>  1 file changed, 84 insertions(+), 80 deletions(-)

I think it is a great idea, it always takes a moment to figure out if
a function is part of the fast callchain or not..

(even better would be to shift the fast stuff into its own file, but I
expect that is too much)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason

Re: [PATCH RFC 1/3] mm/gup: consistently name GUP-fast functions

[David Hildenbrand]

On 27.03.24 14:52, Jason Gunthorpe wrote:
> On Wed, Mar 27, 2024 at 02:05:36PM +0100, David Hildenbrand wrote:
>> Let's consistently call the "fast-only" part of GUP "GUP-fast" and rename
>> all relevant internal functions to start with "gup_fast", to make it
>> clearer that this is not ordinary GUP. The current mixture of
>> "lockless", "gup" and "gup_fast" is confusing.
>>
>> Further, avoid the term "huge" when talking about a "leaf" -- for
>> example, we nowadays check pmd_leaf() because pmd_huge() is gone. For the
>> "hugepd"/"hugepte" stuff, it's part of the name ("is_hugepd"), so that
>> says.
>>
>> What remains is the "external" interface:
>> * get_user_pages_fast_only()
>> * get_user_pages_fast()
>> * pin_user_pages_fast()
>>
>> And the "internal" interface that handles GUP-fast + fallback:
>> * internal_get_user_pages_fast()
> 
> This would like a better name too. How about gup_fast_fallback() ?

Yes, I was not able to come up with something I liked. But I do like
your proposal, so I'll do that!

[...]

> 
> I think it is a great idea, it always takes a moment to figure out if
> a function is part of the fast callchain or not..
> 
> (even better would be to shift the fast stuff into its own file, but I
> expect that is too much)

Yes, one step at a time :)

> 
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Thanks Jason!

-- 
Cheers,

David / dhildenb

Re: [PATCH RFC 1/3] mm/gup: consistently name GUP-fast functions

[Mike Rapoport]

On Wed, Mar 27, 2024 at 02:05:36PM +0100, David Hildenbrand wrote:
> Let's consistently call the "fast-only" part of GUP "GUP-fast" and rename
> all relevant internal functions to start with "gup_fast", to make it
> clearer that this is not ordinary GUP. The current mixture of
> "lockless", "gup" and "gup_fast" is confusing.
> 
> Further, avoid the term "huge" when talking about a "leaf" -- for
> example, we nowadays check pmd_leaf() because pmd_huge() is gone. For the
> "hugepd"/"hugepte" stuff, it's part of the name ("is_hugepd"), so that
> says.

typo: stays

> What remains is the "external" interface:
> * get_user_pages_fast_only()
> * get_user_pages_fast()
> * pin_user_pages_fast()
> 
> And the "internal" interface that handles GUP-fast + fallback:
> * internal_get_user_pages_fast()
> 
> The high-level internal function for GUP-fast is now:
> * gup_fast()
> 
> The basic GUP-fast walker functions:
> * gup_pgd_range() -> gup_fast_pgd_range()
> * gup_p4d_range() -> gup_fast_p4d_range()
> * gup_pud_range() -> gup_fast_pud_range()
> * gup_pmd_range() -> gup_fast_pmd_range()
> * gup_pte_range() -> gup_fast_pte_range()
> * gup_huge_pgd()  -> gup_fast_pgd_leaf()
> * gup_huge_pud()  -> gup_fast_pud_leaf()
> * gup_huge_pmd()  -> gup_fast_pmd_leaf()
> 
> The weird hugepd stuff:
> * gup_huge_pd() -> gup_fast_hugepd()
> * gup_hugepte() -> gup_fast_hugepte()
> 
> The weird devmap stuff:
> * __gup_device_huge_pud() -> gup_fast_devmap_pud_leaf()
> * __gup_device_huge_pmd   -> gup_fast_devmap_pmd_leaf()
> * __gup_device_huge()     -> gup_fast_devmap_leaf()
> 
> Helper functions:
> * unpin_user_pages_lockless() -> gup_fast_unpin_user_pages()
> * gup_fast_folio_allowed() is already properly named
> * gup_fast_permitted() is already properly named
> 
> With "gup_fast()", we now even have a function that is referred to in
> comment in mm/mmu_gather.c.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  mm/gup.c | 164 ++++++++++++++++++++++++++++---------------------------
>  1 file changed, 84 insertions(+), 80 deletions(-)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index 03b74b148e30..c293aff30c5d 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -440,7 +440,7 @@ void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
>  }
>  EXPORT_SYMBOL(unpin_user_page_range_dirty_lock);
>  
> -static void unpin_user_pages_lockless(struct page **pages, unsigned long npages)
> +static void gup_fast_unpin_user_pages(struct page **pages, unsigned long npages)
>  {
>  	unsigned long i;
>  	struct folio *folio;
> @@ -2431,7 +2431,7 @@ long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
>  EXPORT_SYMBOL(get_user_pages_unlocked);
>  
>  /*
> - * Fast GUP
> + * GUP-fast
>   *
>   * get_user_pages_fast attempts to pin user pages by walking the page
>   * tables directly and avoids taking locks. Thus the walker needs to be
> @@ -2445,7 +2445,7 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
>   *
>   * Another way to achieve this is to batch up page table containing pages
>   * belonging to more than one mm_user, then rcu_sched a callback to free those
> - * pages. Disabling interrupts will allow the fast_gup walker to both block
> + * pages. Disabling interrupts will allow the gup_fast() walker to both block
>   * the rcu_sched callback, and an IPI that we broadcast for splitting THPs
>   * (which is a relatively rare event). The code below adopts this strategy.
>   *
> @@ -2589,9 +2589,9 @@ static void __maybe_unused undo_dev_pagemap(int *nr, int nr_start,
>   * also check pmd here to make sure pmd doesn't change (corresponds to
>   * pmdp_collapse_flush() in the THP collapse code path).
>   */
> -static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
> -			 unsigned long end, unsigned int flags,
> -			 struct page **pages, int *nr)
> +static int gup_fast_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	struct dev_pagemap *pgmap = NULL;
>  	int nr_start = *nr, ret = 0;
> @@ -2688,20 +2688,19 @@ static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
>   *
>   * For a futex to be placed on a THP tail page, get_futex_key requires a
>   * get_user_pages_fast_only implementation that can pin pages. Thus it's still
> - * useful to have gup_huge_pmd even if we can't operate on ptes.
> + * useful to have gup_fast_pmd_leaf even if we can't operate on ptes.
>   */
> -static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
> -			 unsigned long end, unsigned int flags,
> -			 struct page **pages, int *nr)
> +static int gup_fast_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	return 0;
>  }
>  #endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
>  
>  #if defined(CONFIG_ARCH_HAS_PTE_DEVMAP) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
> -static int __gup_device_huge(unsigned long pfn, unsigned long addr,
> -			     unsigned long end, unsigned int flags,
> -			     struct page **pages, int *nr)
> +static int gup_fast_devmap_leaf(unsigned long pfn, unsigned long addr,
> +	unsigned long end, unsigned int flags, struct page **pages, int *nr)
>  {
>  	int nr_start = *nr;
>  	struct dev_pagemap *pgmap = NULL;
> @@ -2734,15 +2733,15 @@ static int __gup_device_huge(unsigned long pfn, unsigned long addr,
>  	return addr == end;
>  }
>  
> -static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> -				 unsigned long end, unsigned int flags,
> -				 struct page **pages, int *nr)
> +static int gup_fast_devmap_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long fault_pfn;
>  	int nr_start = *nr;
>  
>  	fault_pfn = pmd_pfn(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
> -	if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr))
> +	if (!gup_fast_devmap_leaf(fault_pfn, addr, end, flags, pages, nr))
>  		return 0;
>  
>  	if (unlikely(pmd_val(orig) != pmd_val(*pmdp))) {
> @@ -2752,15 +2751,15 @@ static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
>  	return 1;
>  }
>  
> -static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
> -				 unsigned long end, unsigned int flags,
> -				 struct page **pages, int *nr)
> +static int gup_fast_devmap_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long fault_pfn;
>  	int nr_start = *nr;
>  
>  	fault_pfn = pud_pfn(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
> -	if (!__gup_device_huge(fault_pfn, addr, end, flags, pages, nr))
> +	if (!gup_fast_devmap_leaf(fault_pfn, addr, end, flags, pages, nr))
>  		return 0;
>  
>  	if (unlikely(pud_val(orig) != pud_val(*pudp))) {
> @@ -2770,17 +2769,17 @@ static int __gup_device_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
>  	return 1;
>  }
>  #else
> -static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> -				 unsigned long end, unsigned int flags,
> -				 struct page **pages, int *nr)
> +static int gup_fast_devmap_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	BUILD_BUG();
>  	return 0;
>  }
>  
> -static int __gup_device_huge_pud(pud_t pud, pud_t *pudp, unsigned long addr,
> -				 unsigned long end, unsigned int flags,
> -				 struct page **pages, int *nr)
> +static int gup_fast_devmap_pud_leaf(pud_t pud, pud_t *pudp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	BUILD_BUG();
>  	return 0;
> @@ -2806,9 +2805,9 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
>  	return (__boundary - 1 < end - 1) ? __boundary : end;
>  }
>  
> -static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
> -		       unsigned long end, unsigned int flags,
> -		       struct page **pages, int *nr)
> +static int gup_fast_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long pte_end;
>  	struct page *page;
> @@ -2855,7 +2854,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
>  	return 1;
>  }
>  
> -static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
> +static int gup_fast_hugepd(hugepd_t hugepd, unsigned long addr,
>  		unsigned int pdshift, unsigned long end, unsigned int flags,
>  		struct page **pages, int *nr)
>  {
> @@ -2866,14 +2865,14 @@ static int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
>  	ptep = hugepte_offset(hugepd, addr, pdshift);
>  	do {
>  		next = hugepte_addr_end(addr, end, sz);
> -		if (!gup_hugepte(ptep, sz, addr, end, flags, pages, nr))
> +		if (!gup_fast_hugepte(ptep, sz, addr, end, flags, pages, nr))
>  			return 0;
>  	} while (ptep++, addr = next, addr != end);
>  
>  	return 1;
>  }
>  #else
> -static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
> +static inline int gup_fast_hugepd(hugepd_t hugepd, unsigned long addr,
>  		unsigned int pdshift, unsigned long end, unsigned int flags,
>  		struct page **pages, int *nr)
>  {
> @@ -2881,9 +2880,9 @@ static inline int gup_huge_pd(hugepd_t hugepd, unsigned long addr,
>  }
>  #endif /* CONFIG_ARCH_HAS_HUGEPD */
>  
> -static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> -			unsigned long end, unsigned int flags,
> -			struct page **pages, int *nr)
> +static int gup_fast_pmd_leaf(pmd_t orig, pmd_t *pmdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	struct page *page;
>  	struct folio *folio;
> @@ -2895,8 +2894,8 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
>  	if (pmd_devmap(orig)) {
>  		if (unlikely(flags & FOLL_LONGTERM))
>  			return 0;
> -		return __gup_device_huge_pmd(orig, pmdp, addr, end, flags,
> -					     pages, nr);
> +		return gup_fast_devmap_pmd_leaf(orig, pmdp, addr, end, flags,
> +					        pages, nr);
>  	}
>  
>  	page = nth_page(pmd_page(orig), (addr & ~PMD_MASK) >> PAGE_SHIFT);
> @@ -2925,9 +2924,9 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,
>  	return 1;
>  }
>  
> -static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
> -			unsigned long end, unsigned int flags,
> -			struct page **pages, int *nr)
> +static int gup_fast_pud_leaf(pud_t orig, pud_t *pudp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	struct page *page;
>  	struct folio *folio;
> @@ -2939,8 +2938,8 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
>  	if (pud_devmap(orig)) {
>  		if (unlikely(flags & FOLL_LONGTERM))
>  			return 0;
> -		return __gup_device_huge_pud(orig, pudp, addr, end, flags,
> -					     pages, nr);
> +		return gup_fast_devmap_pud_leaf(orig, pudp, addr, end, flags,
> +					        pages, nr);
>  	}
>  
>  	page = nth_page(pud_page(orig), (addr & ~PUD_MASK) >> PAGE_SHIFT);
> @@ -2970,9 +2969,9 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr,
>  	return 1;
>  }
>  
> -static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
> -			unsigned long end, unsigned int flags,
> -			struct page **pages, int *nr)
> +static int gup_fast_pgd_leaf(pgd_t orig, pgd_t *pgdp, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	int refs;
>  	struct page *page;
> @@ -3010,8 +3009,9 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr,
>  	return 1;
>  }
>  
> -static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned long end,
> -		unsigned int flags, struct page **pages, int *nr)
> +static int gup_fast_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long next;
>  	pmd_t *pmdp;
> @@ -3025,11 +3025,11 @@ static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned lo
>  			return 0;
>  
>  		if (unlikely(pmd_leaf(pmd))) {
> -			/* See gup_pte_range() */
> +			/* See gup_fast_pte_range() */
>  			if (pmd_protnone(pmd))
>  				return 0;
>  
> -			if (!gup_huge_pmd(pmd, pmdp, addr, next, flags,
> +			if (!gup_fast_pmd_leaf(pmd, pmdp, addr, next, flags,
>  				pages, nr))
>  				return 0;
>  
> @@ -3038,18 +3038,20 @@ static int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, unsigned lo
>  			 * architecture have different format for hugetlbfs
>  			 * pmd format and THP pmd format
>  			 */
> -			if (!gup_huge_pd(__hugepd(pmd_val(pmd)), addr,
> -					 PMD_SHIFT, next, flags, pages, nr))
> +			if (!gup_fast_hugepd(__hugepd(pmd_val(pmd)), addr,
> +					     PMD_SHIFT, next, flags, pages, nr))
>  				return 0;
> -		} else if (!gup_pte_range(pmd, pmdp, addr, next, flags, pages, nr))
> +		} else if (!gup_fast_pte_range(pmd, pmdp, addr, next, flags,
> +					       pages, nr))
>  			return 0;
>  	} while (pmdp++, addr = next, addr != end);
>  
>  	return 1;
>  }
>  
> -static int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, unsigned long end,
> -			 unsigned int flags, struct page **pages, int *nr)
> +static int gup_fast_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long next;
>  	pud_t *pudp;
> @@ -3062,22 +3064,24 @@ static int gup_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr, unsigned lo
>  		if (unlikely(!pud_present(pud)))
>  			return 0;
>  		if (unlikely(pud_leaf(pud))) {
> -			if (!gup_huge_pud(pud, pudp, addr, next, flags,
> -					  pages, nr))
> +			if (!gup_fast_pud_leaf(pud, pudp, addr, next, flags,
> +					       pages, nr))
>  				return 0;
>  		} else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) {
> -			if (!gup_huge_pd(__hugepd(pud_val(pud)), addr,
> -					 PUD_SHIFT, next, flags, pages, nr))
> +			if (!gup_fast_hugepd(__hugepd(pud_val(pud)), addr,
> +					     PUD_SHIFT, next, flags, pages, nr))
>  				return 0;
> -		} else if (!gup_pmd_range(pudp, pud, addr, next, flags, pages, nr))
> +		} else if (!gup_fast_pmd_range(pudp, pud, addr, next, flags,
> +					       pages, nr))
>  			return 0;
>  	} while (pudp++, addr = next, addr != end);
>  
>  	return 1;
>  }
>  
> -static int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, unsigned long end,
> -			 unsigned int flags, struct page **pages, int *nr)
> +static int gup_fast_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
> +		unsigned long end, unsigned int flags, struct page **pages,
> +		int *nr)
>  {
>  	unsigned long next;
>  	p4d_t *p4dp;
> @@ -3091,17 +3095,18 @@ static int gup_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr, unsigned lo
>  			return 0;
>  		BUILD_BUG_ON(p4d_leaf(p4d));
>  		if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
> -			if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
> -					 P4D_SHIFT, next, flags, pages, nr))
> +			if (!gup_fast_hugepd(__hugepd(p4d_val(p4d)), addr,
> +					     P4D_SHIFT, next, flags, pages, nr))
>  				return 0;
> -		} else if (!gup_pud_range(p4dp, p4d, addr, next, flags, pages, nr))
> +		} else if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
> +					       pages, nr))
>  			return 0;
>  	} while (p4dp++, addr = next, addr != end);
>  
>  	return 1;
>  }
>  
> -static void gup_pgd_range(unsigned long addr, unsigned long end,
> +static void gup_fast_pgd_range(unsigned long addr, unsigned long end,
>  		unsigned int flags, struct page **pages, int *nr)
>  {
>  	unsigned long next;
> @@ -3115,19 +3120,20 @@ static void gup_pgd_range(unsigned long addr, unsigned long end,
>  		if (pgd_none(pgd))
>  			return;
>  		if (unlikely(pgd_leaf(pgd))) {
> -			if (!gup_huge_pgd(pgd, pgdp, addr, next, flags,
> -					  pages, nr))
> +			if (!gup_fast_pgd_leaf(pgd, pgdp, addr, next, flags,
> +					       pages, nr))
>  				return;
>  		} else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) {
> -			if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
> -					 PGDIR_SHIFT, next, flags, pages, nr))
> +			if (!gup_fast_hugepd(__hugepd(pgd_val(pgd)), addr,
> +					      PGDIR_SHIFT, next, flags, pages, nr))
>  				return;
> -		} else if (!gup_p4d_range(pgdp, pgd, addr, next, flags, pages, nr))
> +		} else if (!gup_fast_p4d_range(pgdp, pgd, addr, next, flags,
> +					       pages, nr))
>  			return;
>  	} while (pgdp++, addr = next, addr != end);
>  }
>  #else
> -static inline void gup_pgd_range(unsigned long addr, unsigned long end,
> +static inline void gup_fast_pgd_range(unsigned long addr, unsigned long end,
>  		unsigned int flags, struct page **pages, int *nr)
>  {
>  }
> @@ -3144,10 +3150,8 @@ static bool gup_fast_permitted(unsigned long start, unsigned long end)
>  }
>  #endif
>  
> -static unsigned long lockless_pages_from_mm(unsigned long start,
> -					    unsigned long end,
> -					    unsigned int gup_flags,
> -					    struct page **pages)
> +static unsigned long gup_fast(unsigned long start, unsigned long end,
> +		unsigned int gup_flags, struct page **pages)
>  {
>  	unsigned long flags;
>  	int nr_pinned = 0;
> @@ -3175,16 +3179,16 @@ static unsigned long lockless_pages_from_mm(unsigned long start,
>  	 * that come from THPs splitting.
>  	 */
>  	local_irq_save(flags);
> -	gup_pgd_range(start, end, gup_flags, pages, &nr_pinned);
> +	gup_fast_pgd_range(start, end, gup_flags, pages, &nr_pinned);
>  	local_irq_restore(flags);
>  
>  	/*
>  	 * When pinning pages for DMA there could be a concurrent write protect
> -	 * from fork() via copy_page_range(), in this case always fail fast GUP.
> +	 * from fork() via copy_page_range(), in this case always fail GUP-fast.
>  	 */
>  	if (gup_flags & FOLL_PIN) {
>  		if (read_seqcount_retry(&current->mm->write_protect_seq, seq)) {
> -			unpin_user_pages_lockless(pages, nr_pinned);
> +			gup_fast_unpin_user_pages(pages, nr_pinned);
>  			return 0;
>  		} else {
>  			sanity_check_pinned_pages(pages, nr_pinned);
> @@ -3224,7 +3228,7 @@ static int internal_get_user_pages_fast(unsigned long start,
>  	if (unlikely(!access_ok((void __user *)start, len)))
>  		return -EFAULT;
>  
> -	nr_pinned = lockless_pages_from_mm(start, end, gup_flags, pages);
> +	nr_pinned = gup_fast(start, end, gup_flags, pages);
>  	if (nr_pinned == nr_pages || gup_flags & FOLL_FAST_ONLY)
>  		return nr_pinned;
>  
> -- 
> 2.43.2
> 

-- 
Sincerely yours,
Mike.

[PATCH RFC 2/3] mm/treewide: rename CONFIG_HAVE_FAST_GUP to CONFIG_HAVE_GUP_FAST

[David Hildenbrand]

Nowadays, we call it "GUP-fast", the external interface includes
functions like "get_user_pages_fast()", and we renamed all internal
functions to reflect that as well.

Let's make the config option reflect that.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/arm/Kconfig       | 2 +-
 arch/arm64/Kconfig     | 2 +-
 arch/loongarch/Kconfig | 2 +-
 arch/mips/Kconfig      | 2 +-
 arch/powerpc/Kconfig   | 2 +-
 arch/s390/Kconfig      | 2 +-
 arch/sh/Kconfig        | 2 +-
 arch/x86/Kconfig       | 2 +-
 include/linux/rmap.h   | 8 ++++----
 kernel/events/core.c   | 4 ++--
 mm/Kconfig             | 2 +-
 mm/gup.c               | 6 +++---
 mm/internal.h          | 2 +-
 13 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b14aed3a17ab..817918f6635a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -99,7 +99,7 @@ config ARM
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
 	select HAVE_EXIT_THREAD
-	select HAVE_FAST_GUP if ARM_LPAE
+	select HAVE_GUP_FAST if ARM_LPAE
 	select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_TRACER
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7b11c98b3e84..de076a191e9f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -205,7 +205,7 @@ config ARM64
 	select HAVE_SAMPLE_FTRACE_DIRECT
 	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_ERROR_INJECTION
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index a5f300ec6f28..cd642eefd9e5 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -119,7 +119,7 @@ config LOONGARCH
 	select HAVE_EBPF_JIT
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS if !ARCH_STRICT_ALIGN
 	select HAVE_EXIT_THREAD
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUNCTION_ERROR_INJECTION
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 06ef440d16ce..10f7c6d88163 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -68,7 +68,7 @@ config MIPS
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_EBPF_JIT if !CPU_MICROMIPS
 	select HAVE_EXIT_THREAD
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1c4be3373686..e42cc8cd415f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -236,7 +236,7 @@ config PPC
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS	if ARCH_USING_PATCHABLE_FUNCTION_ENTRY || MPROFILE_KERNEL || PPC32
 	select HAVE_EBPF_JIT
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
 	select HAVE_FUNCTION_DESCRIPTORS	if PPC64_ELF_ABI_V1
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8f01ada6845e..d9aed4c93ee6 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -174,7 +174,7 @@ config S390
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FENTRY
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2ad3e29f0ebe..7292542f75e8 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -38,7 +38,7 @@ config SUPERH
 	select HAVE_DEBUG_BUGVERBOSE
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DYNAMIC_FTRACE
-	select HAVE_FAST_GUP if MMU
+	select HAVE_GUP_FAST if MMU
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 39886bab943a..f82171292cf3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -221,7 +221,7 @@ config X86
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
 	select HAVE_EISA
 	select HAVE_EXIT_THREAD
-	select HAVE_FAST_GUP
+	select HAVE_GUP_FAST
 	select HAVE_FENTRY			if X86_64 || DYNAMIC_FTRACE
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_RETVAL	if HAVE_FUNCTION_GRAPH_TRACER
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index b7944a833668..9bf9324214fc 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -284,7 +284,7 @@ static inline int hugetlb_try_share_anon_rmap(struct folio *folio)
 	VM_WARN_ON_FOLIO(!PageAnonExclusive(&folio->page), folio);
 
 	/* Paired with the memory barrier in try_grab_folio(). */
-	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
+	if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
 		smp_mb();
 
 	if (unlikely(folio_maybe_dma_pinned(folio)))
@@ -295,7 +295,7 @@ static inline int hugetlb_try_share_anon_rmap(struct folio *folio)
 	 * This is conceptually a smp_wmb() paired with the smp_rmb() in
 	 * gup_must_unshare().
 	 */
-	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
+	if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
 		smp_mb__after_atomic();
 	return 0;
 }
@@ -541,7 +541,7 @@ static __always_inline int __folio_try_share_anon_rmap(struct folio *folio,
 	 */
 
 	/* Paired with the memory barrier in try_grab_folio(). */
-	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
+	if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
 		smp_mb();
 
 	if (unlikely(folio_maybe_dma_pinned(folio)))
@@ -552,7 +552,7 @@ static __always_inline int __folio_try_share_anon_rmap(struct folio *folio,
 	 * This is conceptually a smp_wmb() paired with the smp_rmb() in
 	 * gup_must_unshare().
 	 */
-	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
+	if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
 		smp_mb__after_atomic();
 	return 0;
 }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 724e6d7e128f..c5a0dc1f135f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7539,7 +7539,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 {
 	u64 size = 0;
 
-#ifdef CONFIG_HAVE_FAST_GUP
+#ifdef CONFIG_HAVE_GUP_FAST
 	pgd_t *pgdp, pgd;
 	p4d_t *p4dp, p4d;
 	pud_t *pudp, pud;
@@ -7587,7 +7587,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 	if (pte_present(pte))
 		size = pte_leaf_size(pte);
 	pte_unmap(ptep);
-#endif /* CONFIG_HAVE_FAST_GUP */
+#endif /* CONFIG_HAVE_GUP_FAST */
 
 	return size;
 }
diff --git a/mm/Kconfig b/mm/Kconfig
index b1448aa81e15..5fd14a536bcc 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -473,7 +473,7 @@ config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
 config HAVE_MEMBLOCK_PHYS_MAP
 	bool
 
-config HAVE_FAST_GUP
+config HAVE_GUP_FAST
 	depends on MMU
 	bool
 
diff --git a/mm/gup.c b/mm/gup.c
index c293aff30c5d..e35c6a6a0301 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2463,7 +2463,7 @@ EXPORT_SYMBOL(get_user_pages_unlocked);
  *
  * This code is based heavily on the PowerPC implementation by Nick Piggin.
  */
-#ifdef CONFIG_HAVE_FAST_GUP
+#ifdef CONFIG_HAVE_GUP_FAST
 
 /*
  * Used in the GUP-fast path to determine whether GUP is permitted to work on
@@ -3137,7 +3137,7 @@ static inline void gup_fast_pgd_range(unsigned long addr, unsigned long end,
 		unsigned int flags, struct page **pages, int *nr)
 {
 }
-#endif /* CONFIG_HAVE_FAST_GUP */
+#endif /* CONFIG_HAVE_GUP_FAST */
 
 #ifndef gup_fast_permitted
 /*
@@ -3157,7 +3157,7 @@ static unsigned long gup_fast(unsigned long start, unsigned long end,
 	int nr_pinned = 0;
 	unsigned seq;
 
-	if (!IS_ENABLED(CONFIG_HAVE_FAST_GUP) ||
+	if (!IS_ENABLED(CONFIG_HAVE_GUP_FAST) ||
 	    !gup_fast_permitted(start, end))
 		return 0;
 
diff --git a/mm/internal.h b/mm/internal.h
index 8e11f7b2da21..c4587c20c881 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1199,7 +1199,7 @@ static inline bool gup_must_unshare(struct vm_area_struct *vma,
 	}
 
 	/* Paired with a memory barrier in folio_try_share_anon_rmap_*(). */
-	if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
+	if (IS_ENABLED(CONFIG_HAVE_GUP_FAST))
 		smp_rmb();
 
 	/*
-- 
2.43.2

Re: [PATCH RFC 2/3] mm/treewide: rename CONFIG_HAVE_FAST_GUP to CONFIG_HAVE_GUP_FAST

[Mike Rapoport]

On Wed, Mar 27, 2024 at 02:05:37PM +0100, David Hildenbrand wrote:
> Nowadays, we call it "GUP-fast", the external interface includes
> functions like "get_user_pages_fast()", and we renamed all internal
> functions to reflect that as well.
> 
> Let's make the config option reflect that.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  arch/arm/Kconfig       | 2 +-
>  arch/arm64/Kconfig     | 2 +-
>  arch/loongarch/Kconfig | 2 +-
>  arch/mips/Kconfig      | 2 +-
>  arch/powerpc/Kconfig   | 2 +-
>  arch/s390/Kconfig      | 2 +-
>  arch/sh/Kconfig        | 2 +-
>  arch/x86/Kconfig       | 2 +-
>  include/linux/rmap.h   | 8 ++++----
>  kernel/events/core.c   | 4 ++--
>  mm/Kconfig             | 2 +-
>  mm/gup.c               | 6 +++---
>  mm/internal.h          | 2 +-
>  13 files changed, 19 insertions(+), 19 deletions(-)
> 

[PATCH RFC 3/3] mm: use "GUP-fast" instead "fast GUP" in remaining comments

[David Hildenbrand]

Let's fixup the remaining comments to consistently call that thing
"GUP-fast". With this change, we consistently call it "GUP-fast".

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/filemap.c    | 2 +-
 mm/khugepaged.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 387b394754fa..c668e11cd6ef 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1810,7 +1810,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
  * C. Return the page to the page allocator
  *
  * This means that any page may have its reference count temporarily
- * increased by a speculative page cache (or fast GUP) lookup as it can
+ * increased by a speculative page cache (or GUP-fast) lookup as it can
  * be allocated by another user before the RCU grace period expires.
  * Because the refcount temporarily acquired here may end up being the
  * last refcount on the page, any page allocation must be freeable by
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 38830174608f..6972fa05132e 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1169,7 +1169,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	 * huge and small TLB entries for the same virtual address to
 	 * avoid the risk of CPU bugs in that area.
 	 *
-	 * Parallel fast GUP is fine since fast GUP will back off when
+	 * Parallel GUP-fast is fine since GUP-fast will back off when
 	 * it detects PMD is changed.
 	 */
 	_pmd = pmdp_collapse_flush(vma, address, pmd);
-- 
2.43.2

Re: [PATCH RFC 3/3] mm: use "GUP-fast" instead "fast GUP" in remaining comments

[Mike Rapoport]

On Wed, Mar 27, 2024 at 02:05:38PM +0100, David Hildenbrand wrote:
> Let's fixup the remaining comments to consistently call that thing
> "GUP-fast". With this change, we consistently call it "GUP-fast".
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  mm/filemap.c    | 2 +-
>  mm/khugepaged.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/filemap.c b/mm/filemap.c
> index 387b394754fa..c668e11cd6ef 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -1810,7 +1810,7 @@ EXPORT_SYMBOL(page_cache_prev_miss);
>   * C. Return the page to the page allocator
>   *
>   * This means that any page may have its reference count temporarily
> - * increased by a speculative page cache (or fast GUP) lookup as it can
> + * increased by a speculative page cache (or GUP-fast) lookup as it can
>   * be allocated by another user before the RCU grace period expires.
>   * Because the refcount temporarily acquired here may end up being the
>   * last refcount on the page, any page allocation must be freeable by
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 38830174608f..6972fa05132e 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -1169,7 +1169,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
>  	 * huge and small TLB entries for the same virtual address to
>  	 * avoid the risk of CPU bugs in that area.
>  	 *
> -	 * Parallel fast GUP is fine since fast GUP will back off when
> +	 * Parallel GUP-fast is fine since GUP-fast will back off when
>  	 * it detects PMD is changed.
>  	 */
>  	_pmd = pmdp_collapse_flush(vma, address, pmd);
> -- 
> 2.43.2
> 

-- 
Sincerely yours,
Mike.

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Peter Xu]

On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
> Some cleanups around function names, comments and the config option of
> "GUP-fast" -- GUP without "lock" safety belts on.
> 
> With this cleanup it's easy to judge which functions are GUP-fast specific.
> We now consistently call it "GUP-fast", avoiding mixing it with "fast GUP",
> "lockless", or simply "gup" (which I always considered confusing in the
> ode).
> 
> So the magic now happens in functions that contain "gup_fast", whereby
> gup_fast() is the entry point into that magic. Comments consistently
> reference either "GUP-fast" or "gup_fast()".
> 
> Based on mm-unstable from today. I won't CC arch maintainers, but only
> arch mailing lists, to reduce noise.
> 
> Tested on x86_64, cross compiled on a bunch of archs, whereby some of them
> don't properly even compile on mm-unstable anymore in my usual setup
> (alpha, arc, parisc64, sh) ... maybe the cross compilers are outdated,
> but there are no new ones around. Hm.

I'm not sure what config you tried there; as I am doing some build tests
recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
avoid a lot of issues, I think it's due to libc missing.  But maybe not the
case there.

The series makes sense to me, the naming is confusing.  Btw, thanks for
posting this as RFC. This definitely has a conflict with the other gup
series that I had; I'll post v4 of that shortly.

-- 
Peter Xu

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[David Hildenbrand]

On 27.03.24 16:21, Peter Xu wrote:
> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>> Some cleanups around function names, comments and the config option of
>> "GUP-fast" -- GUP without "lock" safety belts on.
>>
>> With this cleanup it's easy to judge which functions are GUP-fast specific.
>> We now consistently call it "GUP-fast", avoiding mixing it with "fast GUP",
>> "lockless", or simply "gup" (which I always considered confusing in the
>> ode).
>>
>> So the magic now happens in functions that contain "gup_fast", whereby
>> gup_fast() is the entry point into that magic. Comments consistently
>> reference either "GUP-fast" or "gup_fast()".
>>
>> Based on mm-unstable from today. I won't CC arch maintainers, but only
>> arch mailing lists, to reduce noise.
>>
>> Tested on x86_64, cross compiled on a bunch of archs, whereby some of them
>> don't properly even compile on mm-unstable anymore in my usual setup
>> (alpha, arc, parisc64, sh) ... maybe the cross compilers are outdated,
>> but there are no new ones around. Hm.
> 
> I'm not sure what config you tried there; as I am doing some build tests
> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
> case there.

CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
example for alpha and arc, the Fedora gcc is "13.2.1".


I compile quite some targets, usually with defconfig. From my compile script:

# COMPILER NAME ARCH CROSS_COMPILE CONFIG(if different from defconfig)

compile_gcc "alpha" "alpha" "alpha-linux-gnu-"
compile_gcc "arc" "arc" "arc-linux-gnu-"
compile_gcc "arm" "arm" "arm-linux-gnu-" "axm55xx_defconfig"
compile_gcc "arm-nommu" "arm" "arm-linux-gnu-" "imxrt_defconfig"
compile_gcc "arm64" "arm64" "aarch64-linux-gnu-"
compile_gcc "csky" "csky" "../cross/gcc-13.2.0-nolibc/csky-linux/bin/csky-linux-"
compile_gcc "loongarch" "loongarch" "../cross/gcc-13.2.0-nolibc/loongarch64-linux/bin/loongarch64-linux-"
compile_gcc "m68k-nommu" "m68k" "m68k-linux-gnu-" "amcore_defconfig"
compile_gcc "m68k-sun3" "m68k" "m68k-linux-gnu-" "sun3_defconfig"
compile_gcc "m68k-coldfire" "m68k" "m68k-linux-gnu-" "m5475evb_defconfig"
compile_gcc "m68k-virt" "m68k" "m68k-linux-gnu-" "virt_defconfig"
compile_gcc "microblaze" "microblaze" "microblaze-linux-gnu-"
compile_gcc "mips64" "mips" "mips64-linux-gnu-" "bigsur_defconfig"
compile_gcc "mips32-xpa" "mips" "mips64-linux-gnu-" "maltaup_xpa_defconfig"
compile_gcc "mips32-alchemy" "mips" "mips64-linux-gnu-" "gpr_defconfig"
compile_gcc "mips32" "mips" "mips64-linux-gnu-"
compile_gcc "nios2" "nios2" "nios2-linux-gnu-" "3c120_defconfig"
compile_gcc "openrisc" "openrisc" "../cross/gcc-13.2.0-nolibc/or1k-linux/bin/or1k-linux-" "virt_defconfig"
compile_gcc "parisc32" "parisc" "hppa-linux-gnu-" "generic-32bit_defconfig"
compile_gcc "parisc64" "parisc" "hppa64-linux-gnu-" "generic-64bit_defconfig"
compile_gcc "riscv32" "riscv" "riscv64-linux-gnu-" "32-bit.config"
compile_gcc "riscv64" "riscv" "riscv64-linux-gnu-" "64-bit.config"
compile_gcc "riscv64-nommu" "riscv" "riscv64-linux-gnu-" "nommu_virt_defconfig"
compile_gcc "s390x" "s390" "s390x-linux-gnu-"
compile_gcc "sh" "sh" "../cross/gcc-13.2.0-nolibc/sh4-linux/bin/sh4-linux-"
compile_gcc "sparc32" "sparc" "../cross/gcc-13.2.0-nolibc/sparc-linux/bin/sparc-linux-" "sparc32_defconfig"
compile_gcc "sparc64" "sparc" "../cross/gcc-13.2.0-nolibc/sparc64-linux/bin/sparc64-linux-" "sparc64_defconfig"
compile_gcc "uml64" "um" "" "x86_64_defconfig"
compile_gcc "x86" "x86" "" "i386_defconfig"
compile_gcc "x86-pae" "x86" "" "i386_defconfig"
compile_gcc "x86_64" "x86" ""
compile_gcc "xtensa" "xtensa" "../cross/gcc-13.2.0-nolibc/xtensa-linux/bin/xtensa-linux-" "virt_defconfig"
compile_gcc "powernv" "powerpc" "../cross/gcc-13.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-" "powernv_defconfig"
compile_gcc "pseries" "powerpc" "../cross/gcc-13.2.0-nolibc/powerpc64-linux/bin/powerpc64-linux-" "pseries_defconfig"



Some of them look like mm-unstable issue, For example, arm64 fails with

   CC      arch/arm64/mm/extable.o
In file included from ./include/linux/hugetlb.h:828,
                  from security/commoncap.c:19:
./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of 'arch_clear_hugetlb_flags'
    25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/hugetlb.h:840:20: note: in expansion of macro 'arch_clear_hugetlb_flags'
   840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of 'arch_clear_hugetlb_flags' with t
ype 'void(struct folio *)'
    21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)
       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
In file included from ./include/linux/hugetlb.h:828,
                  from mm/filemap.c:37:
./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of 'arch_clear_hugetlb_flags'
    25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/hugetlb.h:840:20: note: in expansion of macro 'arch_clear_hugetlb_flags'
   840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of 'arch_clear_hugetlb_flags' with type 'void(struct folio *)'
    21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)


But there is other stuff like (arc):

./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of function 'write_aux_reg' [-Werro
r=implicit-function-declaration]
    82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
       |         ^~~~~~~~~~~~~

or (alpha)

WARNING: modpost: "saved_config" [vmlinux] is COMMON symbol
ERROR: modpost: "memcpy" [fs/reiserfs/reiserfs.ko] undefined!
ERROR: modpost: "memcpy" [fs/nfs/nfs.ko] undefined!
ERROR: modpost: "memcpy" [fs/nfs/nfsv3.ko] undefined!
ERROR: modpost: "memcpy" [fs/nfsd/nfsd.ko] undefined!
ERROR: modpost: "memcpy" [fs/lockd/lockd.ko] undefined!
ERROR: modpost: "memcpy" [crypto/crypto.ko] undefined!
ERROR: modpost: "memcpy" [crypto/crypto_algapi.ko] undefined!
ERROR: modpost: "memcpy" [crypto/aead.ko] undefined!
ERROR: modpost: "memcpy" [crypto/crypto_skcipher.ko] undefined!
ERROR: modpost: "memcpy" [crypto/seqiv.ko] undefined!


> 
> The series makes sense to me, the naming is confusing.  Btw, thanks for
> posting this as RFC. This definitely has a conflict with the other gup
> series that I had; I'll post v4 of that shortly.

Yes, I will rebase on top of that!

-- 
Cheers,

David / dhildenb

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Ryan Roberts]

> 
> Some of them look like mm-unstable issue, For example, arm64 fails with
> 
>   CC      arch/arm64/mm/extable.o
> In file included from ./include/linux/hugetlb.h:828,
>                  from security/commoncap.c:19:
> ./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of
> 'arch_clear_hugetlb_flags'
>    25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
>       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/hugetlb.h:840:20: note: in expansion of macro
> 'arch_clear_hugetlb_flags'
>   840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
>       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
> ./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of
> 'arch_clear_hugetlb_flags' with t
> ype 'void(struct folio *)'
>    21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)
>       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
> In file included from ./include/linux/hugetlb.h:828,
>                  from mm/filemap.c:37:
> ./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of
> 'arch_clear_hugetlb_flags'
>    25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
>       |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/hugetlb.h:840:20: note: in expansion of macro
> 'arch_clear_hugetlb_flags'
>   840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
>       |                    ^~~~~~~~~~~~~~~~~~~~~~~~
> ./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of
> 'arch_clear_hugetlb_flags' with type 'void(struct folio *)'
>    21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)

see: https://lore.kernel.org/linux-mm/ZgQvNKGdlDkwhQEX@casper.infradead.org/

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[David Hildenbrand]

On 27.03.24 16:46, Ryan Roberts wrote:
>>
>> Some of them look like mm-unstable issue, For example, arm64 fails with
>>
>>    CC      arch/arm64/mm/extable.o
>> In file included from ./include/linux/hugetlb.h:828,
>>                   from security/commoncap.c:19:
>> ./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of
>> 'arch_clear_hugetlb_flags'
>>     25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
>>        |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
>> ./include/linux/hugetlb.h:840:20: note: in expansion of macro
>> 'arch_clear_hugetlb_flags'
>>    840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
>>        |                    ^~~~~~~~~~~~~~~~~~~~~~~~
>> ./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of
>> 'arch_clear_hugetlb_flags' with t
>> ype 'void(struct folio *)'
>>     21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)
>>        |                    ^~~~~~~~~~~~~~~~~~~~~~~~
>> In file included from ./include/linux/hugetlb.h:828,
>>                   from mm/filemap.c:37:
>> ./arch/arm64/include/asm/hugetlb.h:25:34: error: redefinition of
>> 'arch_clear_hugetlb_flags'
>>     25 | #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
>>        |                                  ^~~~~~~~~~~~~~~~~~~~~~~~
>> ./include/linux/hugetlb.h:840:20: note: in expansion of macro
>> 'arch_clear_hugetlb_flags'
>>    840 | static inline void arch_clear_hugetlb_flags(struct folio *folio) { }
>>        |                    ^~~~~~~~~~~~~~~~~~~~~~~~
>> ./arch/arm64/include/asm/hugetlb.h:21:20: note: previous definition of
>> 'arch_clear_hugetlb_flags' with type 'void(struct folio *)'
>>     21 | static inline void arch_clear_hugetlb_flags(struct folio *folio)
> 
> see: https://lore.kernel.org/linux-mm/ZgQvNKGdlDkwhQEX@casper.infradead.org/
> 

Yes, besides the other failures I see (odd targets), I was expecting 
that someone else noticed that already :) thanks!

-- 
Cheers,

David / dhildenb

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Arnd Bergmann]

On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
> On 27.03.24 16:21, Peter Xu wrote:
>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>> 
>> I'm not sure what config you tried there; as I am doing some build tests
>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
>> case there.
>
> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
> example for alpha and arc, the Fedora gcc is "13.2.1".

>
> But there is other stuff like (arc):
>
> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of 
> function 'write_aux_reg' [-Werro
> r=implicit-function-declaration]
>     82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
>        |         ^~~~~~~~~~~~~

Seems to be missing an #include of soc/arc/aux.h, but I can't
tell when this first broke without bisecting.

> or (alpha)
>
> WARNING: modpost: "saved_config" [vmlinux] is COMMON symbol
> ERROR: modpost: "memcpy" [fs/reiserfs/reiserfs.ko] undefined!
> ERROR: modpost: "memcpy" [fs/nfs/nfs.ko] undefined!
> ERROR: modpost: "memcpy" [fs/nfs/nfsv3.ko] undefined!
> ERROR: modpost: "memcpy" [fs/nfsd/nfsd.ko] undefined!
> ERROR: modpost: "memcpy" [fs/lockd/lockd.ko] undefined!
> ERROR: modpost: "memcpy" [crypto/crypto.ko] undefined!
> ERROR: modpost: "memcpy" [crypto/crypto_algapi.ko] undefined!
> ERROR: modpost: "memcpy" [crypto/aead.ko] undefined!
> ERROR: modpost: "memcpy" [crypto/crypto_skcipher.ko] undefined!
> ERROR: modpost: "memcpy" [crypto/seqiv.ko] undefined!

Al did a series to fix various build problems on alpha, see
https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git/log/?h=work.alpha
Not sure if he still has to send them to Matt, or if Matt
just needs to apply them.

I also have some alpha patches that I should send upstream.

     Arnd

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Vineet Gupta]

+CC Alexey

On 3/27/24 09:22, Arnd Bergmann wrote:
> On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
>> On 27.03.24 16:21, Peter Xu wrote:
>>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>>>
>>> I'm not sure what config you tried there; as I am doing some build tests
>>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
>>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
>>> case there.
>> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
>> example for alpha and arc, the Fedora gcc is "13.2.1".
>> But there is other stuff like (arc):
>>
>> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
>> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of 
>> function 'write_aux_reg' [-Werro
>> r=implicit-function-declaration]
>>     82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
>>        |         ^~~~~~~~~~~~~
> Seems to be missing an #include of soc/arc/aux.h, but I can't
> tell when this first broke without bisecting.

Weird I don't see this one but I only have gcc 12 handy ATM.

    gcc version 12.2.1 20230306 (ARC HS GNU/Linux glibc toolchain -
build 1360)

I even tried W=1 (which according to scripts/Makefile.extrawarn) should
include -Werror=implicit-function-declaration but don't see this still.

Tomorrow I'll try building a gcc 13.2.1 for ARC.


>
>> or (alpha)
>>
>> WARNING: modpost: "saved_config" [vmlinux] is COMMON symbol
>> ERROR: modpost: "memcpy" [fs/reiserfs/reiserfs.ko] undefined!
>> ERROR: modpost: "memcpy" [fs/nfs/nfs.ko] undefined!
>> ERROR: modpost: "memcpy" [fs/nfs/nfsv3.ko] undefined!
>> ERROR: modpost: "memcpy" [fs/nfsd/nfsd.ko] undefined!
>> ERROR: modpost: "memcpy" [fs/lockd/lockd.ko] undefined!
>> ERROR: modpost: "memcpy" [crypto/crypto.ko] undefined!
>> ERROR: modpost: "memcpy" [crypto/crypto_algapi.ko] undefined!
>> ERROR: modpost: "memcpy" [crypto/aead.ko] undefined!
>> ERROR: modpost: "memcpy" [crypto/crypto_skcipher.ko] undefined!
>> ERROR: modpost: "memcpy" [crypto/seqiv.ko] undefined!

Are these from ARC build or otherwise ?

Thx,
-Vineet

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Arnd Bergmann]

On Thu, Mar 28, 2024, at 06:51, Vineet Gupta wrote:
> On 3/27/24 09:22, Arnd Bergmann wrote:
>> On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
>>> On 27.03.24 16:21, Peter Xu wrote:
>>>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>>>>
>>>> I'm not sure what config you tried there; as I am doing some build tests
>>>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
>>>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
>>>> case there.
>>> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
>>> example for alpha and arc, the Fedora gcc is "13.2.1".
>>> But there is other stuff like (arc):
>>>
>>> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
>>> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of 
>>> function 'write_aux_reg' [-Werro
>>> r=implicit-function-declaration]
>>>     82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
>>>        |         ^~~~~~~~~~~~~
>> Seems to be missing an #include of soc/arc/aux.h, but I can't
>> tell when this first broke without bisecting.
>
> Weird I don't see this one but I only have gcc 12 handy ATM.
>
>     gcc version 12.2.1 20230306 (ARC HS GNU/Linux glibc toolchain -
> build 1360)
>
> I even tried W=1 (which according to scripts/Makefile.extrawarn) should
> include -Werror=implicit-function-declaration but don't see this still.
>
> Tomorrow I'll try building a gcc 13.2.1 for ARC.

David reported them with the toolchains I built at
https://mirrors.edge.kernel.org/pub/tools/crosstool/
I'm fairly sure the problem is specific to the .config
and tree, not the toolchain though.

>>> or (alpha)
>>>
>>> WARNING: modpost: "saved_config" [vmlinux] is COMMON symbol
>>> ERROR: modpost: "memcpy" [fs/reiserfs/reiserfs.ko] undefined!
>>> ERROR: modpost: "memcpy" [fs/nfs/nfs.ko] undefined!
>>> ERROR: modpost: "memcpy" [fs/nfs/nfsv3.ko] undefined!
>>> ERROR: modpost: "memcpy" [fs/nfsd/nfsd.ko] undefined!
>>> ERROR: modpost: "memcpy" [fs/lockd/lockd.ko] undefined!
>>> ERROR: modpost: "memcpy" [crypto/crypto.ko] undefined!
>>> ERROR: modpost: "memcpy" [crypto/crypto_algapi.ko] undefined!
>>> ERROR: modpost: "memcpy" [crypto/aead.ko] undefined!
>>> ERROR: modpost: "memcpy" [crypto/crypto_skcipher.ko] undefined!
>>> ERROR: modpost: "memcpy" [crypto/seqiv.ko] undefined!
>
> Are these from ARC build or otherwise ?

This was arch/alpha.

      Arnd

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Mike Rapoport]

On Thu, Mar 28, 2024 at 07:09:13AM +0100, Arnd Bergmann wrote:
> On Thu, Mar 28, 2024, at 06:51, Vineet Gupta wrote:
> > On 3/27/24 09:22, Arnd Bergmann wrote:
> >> On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
> >>> On 27.03.24 16:21, Peter Xu wrote:
> >>>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
> >>>>
> >>>> I'm not sure what config you tried there; as I am doing some build tests
> >>>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
> >>>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
> >>>> case there.
> >>> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
> >>> example for alpha and arc, the Fedora gcc is "13.2.1".
> >>> But there is other stuff like (arc):
> >>>
> >>> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
> >>> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of 
> >>> function 'write_aux_reg' [-Werro
> >>> r=implicit-function-declaration]
> >>>     82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
> >>>        |         ^~~~~~~~~~~~~
> >> Seems to be missing an #include of soc/arc/aux.h, but I can't
> >> tell when this first broke without bisecting.
> >
> > Weird I don't see this one but I only have gcc 12 handy ATM.
> >
> >     gcc version 12.2.1 20230306 (ARC HS GNU/Linux glibc toolchain -
> > build 1360)
> >
> > I even tried W=1 (which according to scripts/Makefile.extrawarn) should
> > include -Werror=implicit-function-declaration but don't see this still.
> >
> > Tomorrow I'll try building a gcc 13.2.1 for ARC.
> 
> David reported them with the toolchains I built at
> https://mirrors.edge.kernel.org/pub/tools/crosstool/
> I'm fairly sure the problem is specific to the .config
> and tree, not the toolchain though.

This happens with defconfig and both gcc 12.2.0 and gcc 13.2.0 from your
crosstools. I also see these on the current Linus' tree:

arc/kernel/ptrace.c:342:16: warning: no previous prototype for 'syscall_trace_enter' [-Wmissing-prototypes]
arch/arc/kernel/kprobes.c:193:15: warning: no previous prototype for 'arc_kprobe_handler' [-Wmissing-prototypes]

This fixed the warning about write_aux_reg for me, probably Vineet would
want this include somewhere else...

diff --git a/arch/arc/include/asm/mmu-arcv2.h b/arch/arc/include/asm/mmu-arcv2.h
index ed9036d4ede3..0fca342d7b79 100644
--- a/arch/arc/include/asm/mmu-arcv2.h
+++ b/arch/arc/include/asm/mmu-arcv2.h
@@ -69,6 +69,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/arcregs.h>
+
 struct mm_struct;
 extern int pae40_exist_but_not_enab(void);
 
 
> >>> or (alpha)
> >>>
> >>> WARNING: modpost: "saved_config" [vmlinux] is COMMON symbol
> >>> ERROR: modpost: "memcpy" [fs/reiserfs/reiserfs.ko] undefined!
> >>> ERROR: modpost: "memcpy" [fs/nfs/nfs.ko] undefined!
> >>> ERROR: modpost: "memcpy" [fs/nfs/nfsv3.ko] undefined!
> >>> ERROR: modpost: "memcpy" [fs/nfsd/nfsd.ko] undefined!
> >>> ERROR: modpost: "memcpy" [fs/lockd/lockd.ko] undefined!
> >>> ERROR: modpost: "memcpy" [crypto/crypto.ko] undefined!
> >>> ERROR: modpost: "memcpy" [crypto/crypto_algapi.ko] undefined!
> >>> ERROR: modpost: "memcpy" [crypto/aead.ko] undefined!
> >>> ERROR: modpost: "memcpy" [crypto/crypto_skcipher.ko] undefined!
> >>> ERROR: modpost: "memcpy" [crypto/seqiv.ko] undefined!
> >
> > Are these from ARC build or otherwise ?
> 
> This was arch/alpha.
> 
>       Arnd

-- 
Sincerely yours,
Mike.

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[David Hildenbrand]

On 28.03.24 08:15, Mike Rapoport wrote:
> On Thu, Mar 28, 2024 at 07:09:13AM +0100, Arnd Bergmann wrote:
>> On Thu, Mar 28, 2024, at 06:51, Vineet Gupta wrote:
>>> On 3/27/24 09:22, Arnd Bergmann wrote:
>>>> On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
>>>>> On 27.03.24 16:21, Peter Xu wrote:
>>>>>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>>>>>>
>>>>>> I'm not sure what config you tried there; as I am doing some build tests
>>>>>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
>>>>>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
>>>>>> case there.
>>>>> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
>>>>> example for alpha and arc, the Fedora gcc is "13.2.1".
>>>>> But there is other stuff like (arc):
>>>>>
>>>>> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
>>>>> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of
>>>>> function 'write_aux_reg' [-Werro
>>>>> r=implicit-function-declaration]
>>>>>      82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
>>>>>         |         ^~~~~~~~~~~~~
>>>> Seems to be missing an #include of soc/arc/aux.h, but I can't
>>>> tell when this first broke without bisecting.
>>>
>>> Weird I don't see this one but I only have gcc 12 handy ATM.
>>>
>>>      gcc version 12.2.1 20230306 (ARC HS GNU/Linux glibc toolchain -
>>> build 1360)
>>>
>>> I even tried W=1 (which according to scripts/Makefile.extrawarn) should
>>> include -Werror=implicit-function-declaration but don't see this still.
>>>
>>> Tomorrow I'll try building a gcc 13.2.1 for ARC.
>>
>> David reported them with the toolchains I built at
>> https://mirrors.edge.kernel.org/pub/tools/crosstool/
>> I'm fairly sure the problem is specific to the .config
>> and tree, not the toolchain though.
> 
> This happens with defconfig and both gcc 12.2.0 and gcc 13.2.0 from your
> crosstools. I also see these on the current Linus' tree:
> 
> arc/kernel/ptrace.c:342:16: warning: no previous prototype for 'syscall_trace_enter' [-Wmissing-prototypes]
> arch/arc/kernel/kprobes.c:193:15: warning: no previous prototype for 'arc_kprobe_handler' [-Wmissing-prototypes]
> 
> This fixed the warning about write_aux_reg for me, probably Vineet would
> want this include somewhere else...
> 
> diff --git a/arch/arc/include/asm/mmu-arcv2.h b/arch/arc/include/asm/mmu-arcv2.h
> index ed9036d4ede3..0fca342d7b79 100644
> --- a/arch/arc/include/asm/mmu-arcv2.h
> +++ b/arch/arc/include/asm/mmu-arcv2.h
> @@ -69,6 +69,8 @@
>   
>   #ifndef __ASSEMBLY__
>   
> +#include <asm/arcregs.h>
> +
>   struct mm_struct;
>   extern int pae40_exist_but_not_enab(void);


Here are all err+warn I see with my configs on Linus' tree from today (not mm-unstable).
Most of them are warnings due to missing prototypes or missing "clone3".

Parisc64 seems to be a bit more broken. Maybe nobody cares about parisc64 anymore? Or
it's a toolchain issue, don't know.

xtensa is also broken, but "invalid register" smells like a toolchain issue to me.


Maybe all known/expected, just posting it if anybody cares. I can share my full build script
on request.



[INFO] Compiling alpha
[INFO] 0 errors
[INFO] 102 warnings
[PASS]

$ cat alpha_log  | grep warn
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]
arch/alpha/lib/checksum.c:45:9: warning: no previous prototype for 'csum_tcpudp_magic' [-Wmissing-prototypes]
arch/alpha/lib/checksum.c:54:8: warning: no previous prototype for 'csum_tcpudp_nofold' [-Wmissing-prototypes]
arch/alpha/lib/checksum.c:145:9: warning: no previous prototype for 'ip_fast_csum' [-Wmissing-prototypes]
arch/alpha/lib/checksum.c:163:8: warning: no previous prototype for 'csum_partial' [-Wmissing-prototypes]
arch/alpha/lib/checksum.c:180:9: warning: no previous prototype for 'ip_compute_csum' [-Wmissing-prototypes]
arch/alpha/kernel/traps.c:211:1: warning: no previous prototype for 'do_entArith' [-Wmissing-prototypes]
arch/alpha/kernel/traps.c:233:1: warning: no previous prototype for 'do_entIF' [-Wmissing-prototypes]
arch/alpha/kernel/traps.c:400:1: warning: no previous prototype for 'do_entDbg' [-Wmissing-prototypes]
arch/alpha/kernel/traps.c:436:1: warning: no previous prototype for 'do_entUna' [-Wmissing-prototypes]
arch/alpha/kernel/traps.c:721:1: warning: no previous prototype for 'do_entUnaUser' [-Wmissing-prototypes]
arch/alpha/mm/init.c:261:1: warning: no previous prototype for 'srm_paging_stop' [-Wmissing-prototypes]
arch/alpha/lib/fpreg.c:20:1: warning: no previous prototype for 'alpha_read_fp_reg' [-Wmissing-prototypes]
[....]

[INFO] Compiling arc
[INFO] 0 errors
[INFO] 2 warnings
[PASS]

$ cat arc_log  | grep warn
arch/arc/kernel/ptrace.c:342:16: warning: no previous prototype for 'syscall_trace_enter' [-Wmissing-prototypes]
arch/arc/kernel/kprobes.c:193:15: warning: no previous prototype for 'arc_kprobe_handler' [-Wmissing-prototypes]


[INFO] Compiling hexagon
[INFO] 0 errors
[INFO] 1 warnings
[PASS]

  $ cat hexagon_log  | grep warn
<stdin>:1519:2: warning: syscall clone3 not implemented [-W#warnings]
  1519 | #warning syscall clone3 not implemented
1 warning generated.


[INFO] Compiling mips64
[INFO] 0 errors
[INFO] 15 warnings
[PASS]

  $ cat mips64_log  | grep warn
arch/mips/sibyte/bcm1480/setup.c:104:13: warning: no previous prototype for 'bcm1480_setup' [-Wmissing-prototypes]
arch/mips/sibyte/bcm1480/irq.c:200:13: warning: no previous prototype for 'init_bcm1480_irqs' [-Wmissing-prototypes]
arch/mips/sibyte/bcm1480/time.c:10:13: warning: no previous prototype for 'plat_time_init' [-Wmissing-prototypes]
arch/mips/sibyte/bcm1480/smp.c:49:6: warning: no previous prototype for 'bcm1480_smp_init' [-Wmissing-prototypes]
arch/mips/sibyte/bcm1480/smp.c:158:6: warning: no previous prototype for 'bcm1480_mailbox_interrupt' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/setup.c:59:5: warning: no previous prototype for 'swarm_be_handler' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_xicor1241.c:108:5: warning: no previous prototype for 'xicor_set_time' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_xicor1241.c:167:10: warning: no previous prototype for 'xicor_get_time' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_xicor1241.c:203:5: warning: no previous prototype for 'xicor_probe' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_m41t81.c:139:5: warning: no previous prototype for 'm41t81_set_time' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_m41t81.c:186:10: warning: no previous prototype for 'm41t81_get_time' [-Wmissing-prototypes]
arch/mips/sibyte/swarm/rtc_m41t81.c:219:5: warning: no previous prototype for 'm41t81_probe' [-Wmissing-prototypes]
arch/mips/mm/cerr-sb1.c:165:17: warning: no previous prototype for 'sb1_cache_error' [-Wmissing-prototypes]
arch/mips/kernel/cevt-bcm1480.c:96:6: warning: no previous prototype for 'sb1480_clockevent_init' [-Wmissing-prototypes]
arch/mips/kernel/csrc-bcm1480.c:37:13: warning: no previous prototype for 'sb1480_clocksource_init' [-Wmissing-prototypes]


[INFO] Compiling mips32-xpa
[INFO] 0 errors
[INFO] 1 warnings
[PASS]

$ cat mips32-xpa_log | grep warn
drivers/uio/uio.c:795:16: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]


[INFO] Compiling mips32-alchemy
[INFO] 0 errors
[INFO] 1 warnings
[PASS]

$ cat mips32-alchemy_log  | grep warn
drivers/net/ethernet/amd/au1000_eth.c:574:6: warning: no previous prototype for 'au1000_ReleaseDB' [-Wmissing-prototypes]


[INFO] Compiling nios2
[INFO] 0 errors
[INFO] 35 warnings
[PASS]

$ cat nios2_log | grep warn
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]
arch/nios2/lib/memcpy.c:160:7: warning: no previous prototype for 'memcpy' [-Wmissing-prototypes]
arch/nios2/lib/memcpy.c:194:7: warning: no previous prototype for 'memcpyb' [-Wmissing-prototypes]
arch/nios2/mm/dma-mapping.c:21:6: warning: no previous prototype for 'arch_sync_dma_for_device' [-Wmissing-prototypes]
arch/nios2/mm/dma-mapping.c:45:6: warning: no previous prototype for 'arch_sync_dma_for_cpu' [-Wmissing-prototypes]
arch/nios2/mm/dma-mapping.c:63:6: warning: no previous prototype for 'arch_dma_prep_coherent' [-Wmissing-prototypes]
arch/nios2/mm/dma-mapping.c:70:7: warning: no previous prototype for 'arch_dma_set_uncached' [-Wmissing-prototypes]
arch/nios2/kernel/irq.c:19:17: warning: no previous prototype for 'do_IRQ' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:34:6: warning: no previous prototype for 'arch_cpu_idle' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:43:6: warning: no previous prototype for 'machine_restart' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:54:6: warning: no previous prototype for 'machine_halt' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:66:6: warning: no previous prototype for 'machine_power_off' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:152:6: warning: no previous prototype for 'dump' [-Wmissing-prototypes]
arch/nios2/kernel/process.c:253:16: warning: no previous prototype for 'nios2_clone' [-Wmissing-prototypes]
[...]


[INFO] Compiling parisc64
[INFO] 79 errors
[INFO] 54 warnings
[FAIL]

$ cat parisc64_log  | grep error
ipc/sem.c:1284:18: error: 'struct semid64_ds' has no member named 'sem_otime_high'; did you mean 'sem_otime'?
ipc/sem.c:1285:18: error: 'struct semid64_ds' has no member named 'sem_ctime_high'; did you mean 'sem_ctime'?
././include/linux/compiler_types.h:449:45: error: call to '__compiletime_assert_276' declared with attribute error: BUILD_BUG_ON failed: sizeof(struct semid64_ds) != 80
ipc/msg.c:567:12: error: 'struct msqid64_ds' has no member named 'msg_stime_high'; did you mean 'msg_stime'?
ipc/msg.c:568:12: error: 'struct msqid64_ds' has no member named 'msg_rtime_high'; did you mean 'msg_rtime'?
ipc/msg.c:569:12: error: 'struct msqid64_ds' has no member named 'msg_ctime_high'; did you mean 'msg_ctime'?
ipc/shm.c:1137:15: error: 'struct shmid64_ds' has no member named 'shm_atime_high'; did you mean 'shm_atime'?
ipc/shm.c:1138:15: error: 'struct shmid64_ds' has no member named 'shm_dtime_high'; did you mean 'shm_dtime'?
ipc/shm.c:1139:15: error: 'struct shmid64_ds' has no member named 'shm_ctime_high'; did you mean 'shm_ctime'?
././include/linux/compiler_types.h:449:45: error: call to '__compiletime_assert_390' declared with attribute error: BUILD_BUG_ON failed: offsetof(struct dst_entry, __rcuref) & 63
././include/linux/compiler_types.h:449:45: error: call to '__compiletime_assert_374' declared with attribute error: BUILD_BUG_ON failed: offsetof(struct dst_entry, __rcuref) & 63
././include/linux/compiler_types.h:449:45: error: call to '__compiletime_assert_382' declared with attribute error: BUILD_BUG_ON failed: offsetof(struct dst_entry, __rcuref) & 63
[...]


[INFO] Compiling sh
[INFO] 0 errors
[INFO] 39 warnings
[PASS]

  $ cat sh_log | grep warn
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]
arch/sh/mm/cache-shx3.c:18:13: warning: no previous prototype for 'shx3_cache_init' [-Wmissing-prototypes]
arch/sh/mm/flush-sh4.c:106:13: warning: no previous prototype for 'sh4__flush_region_init' [-Wmissing-prototypes]
arch/sh/mm/cache-sh4.c:384:13: warning: no previous prototype for 'sh4_cache_init' [-Wmissing-prototypes]
arch/sh/kernel/return_address.c:49:7: warning: no previous prototype for 'return_address' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:10:6: warning: no previous prototype for 'pgd_ctor' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:32:8: warning: no previous prototype for 'pgd_alloc' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:37:6: warning: no previous prototype for 'pgd_free' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:43:6: warning: no previous prototype for 'pud_populate' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:48:8: warning: no previous prototype for 'pmd_alloc_one' [-Wmissing-prototypes]
arch/sh/mm/pgtable.c:53:6: warning: no previous prototype for 'pmd_free' [-Wmissing-prototypes]
arch/sh/mm/tlbex_32.c:22:1: warning: no previous prototype for 'handle_tlbmiss' [-Wmissing-prototypes]
arch/sh/kernel/sys_sh.c:58:16: warning: no previous prototype for 'sys_cacheflush' [-Wmissing-prototypes]
[...]


[INFO] Compiling sparc32
[INFO] 0 errors
[INFO] 1 warnings
[PASS]

$ cat sparc32_log | grep warn
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]


[INFO] Compiling sparc64
[INFO] 0 errors
[INFO] 26 warnings
[PASS]

$ cat sparc64_log | grep warn
<stdin>:1519:2: warning: #warning syscall clone3 not implemented [-Wcpp]
arch/sparc/vdso/vma.c:246:12: warning: no previous prototype for 'init_vdso_image' [-Wmissing-prototypes]
arch/sparc/vdso/vclock_gettime.c:254:1: warning: no previous prototype for '__vdso_clock_gettime' [-Wmissing-prototypes]
arch/sparc/vdso/vclock_gettime.c:282:1: warning: no previous prototype for '__vdso_clock_gettime_stick' [-Wmissing-prototypes]
arch/sparc/vdso/vclock_gettime.c:307:1: warning: no previous prototype for '__vdso_gettimeofday' [-Wmissing-prototypes]
arch/sparc/vdso/vclock_gettime.c:343:1: warning: no previous prototype for '__vdso_gettimeofday_stick' [-Wmissing-prototypes]
arch/sparc/kernel/traps_64.c:253:6: warning: no previous prototype for 'is_no_fault_exception' [-Wmissing-prototypes]
arch/sparc/kernel/traps_64.c:2035:6: warning: no previous prototype for 'do_mcd_err' [-Wmissing-prototypes]
[...]


[INFO] Compiling uml64
[INFO] 0 errors
[INFO] 51 warnings
[PASS]

  $ cat uml64_log | grep warn
arch/x86/um/user-offsets.c:17:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes]
./arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for 'arch_check_bugs' [-Wmissing-prototypes]
arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for 'arch_examine_signal' [-Wmissing-prototypes]
arch/x86/um/fault.c:18:5: warning: no previous prototype for 'arch_fixup' [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for 'poke_user' [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for 'peek_user' [-Wmissing-prototypes]
arch/um/os-Linux/main.c:187:7: warning: no previous prototype for '__wrap_malloc' [-Wmissing-prototypes]
arch/um/os-Linux/main.c:208:7: warning: no previous prototype for '__wrap_calloc' [-Wmissing-prototypes]
arch/um/os-Linux/main.c:222:6: warning: no previous prototype for '__wrap_free' [-Wmissing-prototypes]
arch/um/os-Linux/mem.c:28:6: warning: no previous prototype for 'kasan_map_memory' [-Wmissing-prototypes]
arch/um/os-Linux/mem.c:212:13: warning: no previous prototype for 'check_tmpexec' [-Wmissing-prototypes]
arch/um/os-Linux/signal.c:75:6: warning: no previous prototype for 'sig_handler' [-Wmissing-prototypes]
arch/um/os-Linux/signal.c:111:6: warning: no previous prototype for 'timer_alarm_handler' [-Wmissing-prototypes]
[...]


[INFO] Compiling xtensa
[INFO] 1 errors
[INFO] 1 warnings
[FAIL]

  $ cat xtensa_log | grep Error
./arch/xtensa/include/asm/initialize_mmu.h:57: Error: invalid register 'atomctl' for 'wsr' instruction
make[4]: *** [scripts/Makefile.build:362: arch/xtensa/kernel/head.o] Error 1
make[3]: *** [scripts/Makefile.build:485: arch/xtensa/kernel] Error 2
make[2]: *** [scripts/Makefile.build:485: arch/xtensa] Error 2
make[1]: *** [/home/dhildenb/git/linux-cross/Makefile:1919: .] Error 2
make: *** [Makefile:240: __sub-make] Error 2


-- 
Cheers,

David / dhildenb

Re: [PATCH RFC 0/3] mm/gup: consistently call it GUP-fast

[Vineet Gupta]

On 3/28/24 00:15, Mike Rapoport wrote:
> On Thu, Mar 28, 2024 at 07:09:13AM +0100, Arnd Bergmann wrote:
>> On Thu, Mar 28, 2024, at 06:51, Vineet Gupta wrote:
>>> On 3/27/24 09:22, Arnd Bergmann wrote:
>>>> On Wed, Mar 27, 2024, at 16:39, David Hildenbrand wrote:
>>>>> On 27.03.24 16:21, Peter Xu wrote:
>>>>>> On Wed, Mar 27, 2024 at 02:05:35PM +0100, David Hildenbrand wrote:
>>>>>>
>>>>>> I'm not sure what config you tried there; as I am doing some build tests
>>>>>> recently, I found turning off CONFIG_SAMPLES + CONFIG_GCC_PLUGINS could
>>>>>> avoid a lot of issues, I think it's due to libc missing.  But maybe not the
>>>>>> case there.
>>>>> CCin Arnd; I use some of his compiler chains, others from Fedora directly. For
>>>>> example for alpha and arc, the Fedora gcc is "13.2.1".
>>>>> But there is other stuff like (arc):
>>>>>
>>>>> ./arch/arc/include/asm/mmu-arcv2.h: In function 'mmu_setup_asid':
>>>>> ./arch/arc/include/asm/mmu-arcv2.h:82:9: error: implicit declaration of 
>>>>> function 'write_aux_reg' [-Werro
>>>>> r=implicit-function-declaration]
>>>>>     82 |         write_aux_reg(ARC_REG_PID, asid | MMU_ENABLE);
>>>>>        |         ^~~~~~~~~~~~~
>>>> Seems to be missing an #include of soc/arc/aux.h, but I can't
>>>> tell when this first broke without bisecting.
>>> Weird I don't see this one but I only have gcc 12 handy ATM.
>>>
>>>     gcc version 12.2.1 20230306 (ARC HS GNU/Linux glibc toolchain -
>>> build 1360)
>>>
>>> I even tried W=1 (which according to scripts/Makefile.extrawarn) should
>>> include -Werror=implicit-function-declaration but don't see this still.
>>>
>>> Tomorrow I'll try building a gcc 13.2.1 for ARC.
>> David reported them with the toolchains I built at
>> https://mirrors.edge.kernel.org/pub/tools/crosstool/
>> I'm fairly sure the problem is specific to the .config
>> and tree, not the toolchain though.
> This happens with defconfig and both gcc 12.2.0 and gcc 13.2.0 from your
> crosstools. I also see these on the current Linus' tree:
>
> arc/kernel/ptrace.c:342:16: warning: no previous prototype for 'syscall_trace_enter' [-Wmissing-prototypes]
> arch/arc/kernel/kprobes.c:193:15: warning: no previous prototype for 'arc_kprobe_handler' [-Wmissing-prototypes]

Yep these two I could trigger and fix posted [1]

> This fixed the warning about write_aux_reg for me, probably Vineet would
> want this include somewhere else...
>
> diff --git a/arch/arc/include/asm/mmu-arcv2.h b/arch/arc/include/asm/mmu-arcv2.h
> index ed9036d4ede3..0fca342d7b79 100644
> --- a/arch/arc/include/asm/mmu-arcv2.h
> +++ b/arch/arc/include/asm/mmu-arcv2.h
> @@ -69,6 +69,8 @@
>  
>  #ifndef __ASSEMBLY__
>  
> +#include <asm/arcregs.h>
> +
>  struct mm_struct;
>  extern int pae40_exist_but_not_enab(void);

Thx Mike. Indeed the fix is trivial but on tip of tree I still can't
trigger the warning to even test anything. I'm at following with my
other fixes.

    2024-03-27 962490525cff Merge tag 'probes-fixes-v6.9-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace  

I tried defconfig build as well as the exact config from Linaro report
[2], and/or various toolchains: from snps github, Arnd's crosstool
toolchain.
Granted all of these are linux toolchains - I vaguely remember at some
time, baremetal elf32 toolchain behaved differently due to different
defaults etc.
I have a feeling this was something transient which got fixed up due to
order of header includes etc.

Anyone in the followup email David only reported 2 warnings which have
been tended to as mentioned above - will be sent to Linus soon.

[1]
http://lists.infradead.org/pipermail/linux-snps-arc/2024-March/007916.html
[2]
https://storage.tuxsuite.com/public/linaro/lkft/builds/2eA2VSZdDsL0DMBBhjoauN9IVoK/

Thx,
-Vineet