* [PATCH 0/3] userfaultfd: convert userfaultfd functions to use folios
@ 2023-03-14 3:37 Peng Zhang
2023-03-14 3:37 ` [PATCH 1/3] userfaultfd: convert mcopy_atomic_pte() to use a folio Peng Zhang
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Peng Zhang @ 2023-03-14 3:37 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: akpm, willy, mike.kravetz, vishal.moola, sidhartha.kumar,
wangkefeng.wang, sunnanyong, ZhangPeng
From: ZhangPeng <zhangpeng362@huawei.com>
This patch series converts several userfaultfd functions to use folios.
And this series pass the userfaultfd selftests and the LTP userfaultfd
test cases.
ZhangPeng (3):
userfaultfd: convert mcopy_atomic_pte() to use a folio
userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
userfaultfd: convert __mcopy_atomic() to use a folio
include/linux/hugetlb.h | 4 +--
include/linux/mm.h | 3 +-
include/linux/shmem_fs.h | 2 +-
mm/hugetlb.c | 25 +++++++-------
mm/memory.c | 18 +++++-----
mm/shmem.c | 17 +++++----
mm/userfaultfd.c | 74 +++++++++++++++++++---------------------
7 files changed, 70 insertions(+), 73 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/3] userfaultfd: convert mcopy_atomic_pte() to use a folio
2023-03-14 3:37 [PATCH 0/3] userfaultfd: convert userfaultfd functions to use folios Peng Zhang
@ 2023-03-14 3:37 ` Peng Zhang
2023-03-14 3:37 ` [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() " Peng Zhang
2023-03-14 3:37 ` [PATCH 3/3] userfaultfd: convert __mcopy_atomic() " Peng Zhang
2 siblings, 0 replies; 6+ messages in thread
From: Peng Zhang @ 2023-03-14 3:37 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: akpm, willy, mike.kravetz, vishal.moola, sidhartha.kumar,
wangkefeng.wang, sunnanyong, ZhangPeng
From: ZhangPeng <zhangpeng362@huawei.com>
Call vma_alloc_folio() directly instead of alloc_page_vma(). Add an
assertion that this is a single-page folio and removes several calls to
compound_head().
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
mm/userfaultfd.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 53c3d916ff66..263191c37fb5 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -137,15 +137,15 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
{
void *page_kaddr;
int ret;
- struct page *page;
+ struct folio *folio;
if (!*pagep) {
ret = -ENOMEM;
- page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, dst_vma, dst_addr);
- if (!page)
+ folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
+ if (!folio)
goto out;
- page_kaddr = kmap_local_page(page);
+ page_kaddr = kmap_local_folio(folio, 0);
/*
* The read mmap_lock is held here. Despite the
* mmap_lock being read recursive a deadlock is still
@@ -171,36 +171,37 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
ret = -ENOENT;
- *pagep = page;
+ *pagep = &folio->page;
/* don't free the page */
goto out;
}
- flush_dcache_page(page);
+ flush_dcache_folio(folio);
} else {
- page = *pagep;
+ folio = page_folio(*pagep);
+ VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
*pagep = NULL;
}
/*
- * The memory barrier inside __SetPageUptodate makes sure that
+ * The memory barrier inside __folio_mark_uptodate makes sure that
* preceding stores to the page contents become visible before
* the set_pte_at() write.
*/
- __SetPageUptodate(page);
+ __folio_mark_uptodate(folio);
ret = -ENOMEM;
- if (mem_cgroup_charge(page_folio(page), dst_mm, GFP_KERNEL))
+ if (mem_cgroup_charge(folio, dst_mm, GFP_KERNEL))
goto out_release;
ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
- page, true, wp_copy);
+ &folio->page, true, wp_copy);
if (ret)
goto out_release;
out:
return ret;
out_release:
- put_page(page);
+ folio_put(folio);
goto out;
}
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
2023-03-14 3:37 [PATCH 0/3] userfaultfd: convert userfaultfd functions to use folios Peng Zhang
2023-03-14 3:37 ` [PATCH 1/3] userfaultfd: convert mcopy_atomic_pte() to use a folio Peng Zhang
@ 2023-03-14 3:37 ` Peng Zhang
2023-03-14 8:31 ` Matthew Wilcox
2023-03-14 3:37 ` [PATCH 3/3] userfaultfd: convert __mcopy_atomic() " Peng Zhang
2 siblings, 1 reply; 6+ messages in thread
From: Peng Zhang @ 2023-03-14 3:37 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: akpm, willy, mike.kravetz, vishal.moola, sidhartha.kumar,
wangkefeng.wang, sunnanyong, ZhangPeng
From: ZhangPeng <zhangpeng362@huawei.com>
Change copy_huge_page_from_user() to copy_large_folio_from_user().
Convert hugetlb_mcopy_atomic_pte() and __mcopy_atomic_hugetlb() to use a
folio.
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
include/linux/hugetlb.h | 4 ++--
include/linux/mm.h | 3 +--
mm/hugetlb.c | 25 ++++++++++++-------------
mm/memory.c | 18 ++++++++++--------
mm/userfaultfd.c | 20 +++++++++-----------
5 files changed, 34 insertions(+), 36 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 7c977d234aba..030252ce51bd 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -163,7 +163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy);
#endif /* CONFIG_USERFAULTFD */
bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
@@ -399,7 +399,7 @@ static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
BUG();
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1f79667824eb..5eff770adbaa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3546,9 +3546,8 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
unsigned long addr_hint,
struct vm_area_struct *vma,
unsigned int pages_per_huge_page);
-extern long copy_huge_page_from_user(struct page *dst_page,
+extern long copy_large_folio_from_user(struct folio *dst_folio,
const void __user *usr_src,
- unsigned int pages_per_huge_page,
bool allow_pagefault);
/**
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 07abcb6eb203..20ce2b4e32b1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6163,7 +6163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
@@ -6185,7 +6185,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
if (!folio)
goto out;
folio_in_pagecache = true;
- } else if (!*pagep) {
+ } else if (!*foliop) {
/* If a page already exists, then it's UFFDIO_COPY for
* a non-missing case. Return -EEXIST.
*/
@@ -6201,9 +6201,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
goto out;
}
- ret = copy_huge_page_from_user(&folio->page,
- (const void __user *) src_addr,
- pages_per_huge_page(h), false);
+ ret = copy_large_folio_from_user(folio,
+ (const void __user *) src_addr, false);
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
@@ -6222,7 +6221,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
ret = -ENOMEM;
goto out;
}
- *pagep = &folio->page;
+ *foliop = folio;
/* Set the outparam pagep and return to the caller to
* copy the contents outside the lock. Don't free the
* page.
@@ -6232,23 +6231,23 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
} else {
if (vm_shared &&
hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
- put_page(*pagep);
+ folio_put(*foliop);
ret = -EEXIST;
- *pagep = NULL;
+ *foliop = NULL;
goto out;
}
folio = alloc_hugetlb_folio(dst_vma, dst_addr, 0);
if (IS_ERR(folio)) {
- put_page(*pagep);
+ folio_put(*foliop);
ret = -ENOMEM;
- *pagep = NULL;
+ *foliop = NULL;
goto out;
}
- copy_user_huge_page(&folio->page, *pagep, dst_addr, dst_vma,
+ copy_user_huge_page(&folio->page, &((*foliop)->page), dst_addr, dst_vma,
pages_per_huge_page(h));
- put_page(*pagep);
- *pagep = NULL;
+ folio_put(*foliop);
+ *foliop = NULL;
}
/*
diff --git a/mm/memory.c b/mm/memory.c
index f456f3b5049c..737794b7a19f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5769,26 +5769,28 @@ void copy_user_huge_page(struct page *dst, struct page *src,
process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
}
-long copy_huge_page_from_user(struct page *dst_page,
+long copy_large_folio_from_user(struct folio *dst_folio,
const void __user *usr_src,
- unsigned int pages_per_huge_page,
bool allow_pagefault)
{
void *page_kaddr;
unsigned long i, rc = 0;
- unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
+ unsigned int nr_pages = folio_nr_pages(dst_folio);
+ unsigned long ret_val = nr_pages * PAGE_SIZE;
struct page *subpage;
+ struct folio *inner_folio;
- for (i = 0; i < pages_per_huge_page; i++) {
- subpage = nth_page(dst_page, i);
+ for (i = 0; i < nr_pages; i++) {
+ subpage = folio_page(dst_folio, i);
+ inner_folio = page_folio(subpage);
if (allow_pagefault)
- page_kaddr = kmap(subpage);
+ page_kaddr = kmap_local_folio(inner_folio, 0);
else
page_kaddr = kmap_atomic(subpage);
rc = copy_from_user(page_kaddr,
usr_src + i * PAGE_SIZE, PAGE_SIZE);
if (allow_pagefault)
- kunmap(subpage);
+ kunmap_local(page_kaddr);
else
kunmap_atomic(page_kaddr);
@@ -5796,7 +5798,7 @@ long copy_huge_page_from_user(struct page *dst_page,
if (rc)
break;
- flush_dcache_page(subpage);
+ flush_dcache_folio(inner_folio);
cond_resched();
}
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 263191c37fb5..d7435a1a9d4b 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -324,7 +324,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
pte_t *dst_pte;
unsigned long src_addr, dst_addr;
long copied;
- struct page *page;
+ struct folio *folio;
unsigned long vma_hpagesize;
pgoff_t idx;
u32 hash;
@@ -344,7 +344,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
src_addr = src_start;
dst_addr = dst_start;
copied = 0;
- page = NULL;
+ folio = NULL;
vma_hpagesize = vma_kernel_pagesize(dst_vma);
/*
@@ -413,7 +413,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
}
err = hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma,
- dst_addr, src_addr, mode, &page,
+ dst_addr, src_addr, mode, &folio,
wp_copy);
hugetlb_vma_unlock_read(dst_vma);
@@ -423,12 +423,10 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
if (unlikely(err == -ENOENT)) {
mmap_read_unlock(dst_mm);
- BUG_ON(!page);
+ BUG_ON(!folio);
- err = copy_huge_page_from_user(page,
- (const void __user *)src_addr,
- vma_hpagesize / PAGE_SIZE,
- true);
+ err = copy_large_folio_from_user(folio,
+ (const void __user *) src_addr, true);
if (unlikely(err)) {
err = -EFAULT;
goto out;
@@ -438,7 +436,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_vma = NULL;
goto retry;
} else
- BUG_ON(page);
+ BUG_ON(folio);
if (!err) {
dst_addr += vma_hpagesize;
@@ -455,8 +453,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
out_unlock:
mmap_read_unlock(dst_mm);
out:
- if (page)
- put_page(page);
+ if (folio)
+ folio_put(folio);
BUG_ON(copied < 0);
BUG_ON(err > 0);
BUG_ON(!copied && !err);
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 3/3] userfaultfd: convert __mcopy_atomic() to use a folio
2023-03-14 3:37 [PATCH 0/3] userfaultfd: convert userfaultfd functions to use folios Peng Zhang
2023-03-14 3:37 ` [PATCH 1/3] userfaultfd: convert mcopy_atomic_pte() to use a folio Peng Zhang
2023-03-14 3:37 ` [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() " Peng Zhang
@ 2023-03-14 3:37 ` Peng Zhang
2 siblings, 0 replies; 6+ messages in thread
From: Peng Zhang @ 2023-03-14 3:37 UTC (permalink / raw)
To: linux-mm, linux-kernel
Cc: akpm, willy, mike.kravetz, vishal.moola, sidhartha.kumar,
wangkefeng.wang, sunnanyong, ZhangPeng
From: ZhangPeng <zhangpeng362@huawei.com>
Convert mcopy_atomic_pte(), shmem_mfill_atomic_pte() and
mfill_atomic_pte() to pass in a folio pointer.
Convert __mcopy_atomic() to use a folio.
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
include/linux/shmem_fs.h | 2 +-
mm/shmem.c | 17 ++++++++---------
mm/userfaultfd.c | 35 +++++++++++++++++------------------
3 files changed, 26 insertions(+), 28 deletions(-)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 103d1000a5a2..580af0e3bf02 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -156,7 +156,7 @@ extern int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
bool zeropage, bool wp_copy,
- struct page **pagep);
+ struct folio **foliop);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
diff --git a/mm/shmem.c b/mm/shmem.c
index 448f393d8ab2..986267bf34ef 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2421,7 +2421,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
bool zeropage, bool wp_copy,
- struct page **pagep)
+ struct folio **foliop)
{
struct inode *inode = file_inode(dst_vma->vm_file);
struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2439,14 +2439,14 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
* and now we find ourselves with -ENOMEM. Release the page, to
* avoid a BUG_ON in our caller.
*/
- if (unlikely(*pagep)) {
- put_page(*pagep);
- *pagep = NULL;
+ if (unlikely(*foliop)) {
+ folio_put(*foliop);
+ *foliop = NULL;
}
return -ENOMEM;
}
- if (!*pagep) {
+ if (!*foliop) {
ret = -ENOMEM;
folio = shmem_alloc_folio(gfp, info, pgoff);
if (!folio)
@@ -2478,7 +2478,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
- *pagep = &folio->page;
+ *foliop = folio;
ret = -ENOENT;
/* don't free the page */
goto out_unacct_blocks;
@@ -2489,9 +2489,8 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
clear_user_highpage(&folio->page, dst_addr);
}
} else {
- folio = page_folio(*pagep);
- VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ VM_BUG_ON_FOLIO(folio_test_large(*foliop), folio);
+ *foliop = NULL;
}
VM_BUG_ON(folio_test_locked(folio));
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index d7435a1a9d4b..3d08a1e3cbe7 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -132,14 +132,14 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
void *page_kaddr;
int ret;
struct folio *folio;
- if (!*pagep) {
+ if (!*foliop) {
ret = -ENOMEM;
folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
if (!folio)
@@ -171,16 +171,15 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
ret = -ENOENT;
- *pagep = &folio->page;
+ *foliop = folio;
/* don't free the page */
goto out;
}
flush_dcache_folio(folio);
} else {
- folio = page_folio(*pagep);
- VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ VM_BUG_ON_FOLIO(folio_test_large(*foliop), folio);
+ *foliop = NULL;
}
/*
@@ -476,7 +475,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- struct page **page,
+ struct folio **foliop,
enum mcopy_atomic_mode mode,
bool wp_copy)
{
@@ -500,7 +499,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
if (!(dst_vma->vm_flags & VM_SHARED)) {
if (mode == MCOPY_ATOMIC_NORMAL)
err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
- dst_addr, src_addr, page,
+ dst_addr, src_addr, foliop,
wp_copy);
else
err = mfill_zeropage_pte(dst_mm, dst_pmd,
@@ -509,7 +508,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
err = shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
dst_addr, src_addr,
mode != MCOPY_ATOMIC_NORMAL,
- wp_copy, page);
+ wp_copy, foliop);
}
return err;
@@ -528,7 +527,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
pmd_t *dst_pmd;
unsigned long src_addr, dst_addr;
long copied;
- struct page *page;
+ struct folio *folio;
bool wp_copy;
/*
@@ -544,7 +543,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
src_addr = src_start;
dst_addr = dst_start;
copied = 0;
- page = NULL;
+ folio = NULL;
retry:
mmap_read_lock(dst_mm);
@@ -641,16 +640,16 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
BUG_ON(pmd_trans_huge(*dst_pmd));
err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
- src_addr, &page, mcopy_mode, wp_copy);
+ src_addr, &folio, mcopy_mode, wp_copy);
cond_resched();
if (unlikely(err == -ENOENT)) {
void *page_kaddr;
mmap_read_unlock(dst_mm);
- BUG_ON(!page);
+ BUG_ON(!folio);
- page_kaddr = kmap_local_page(page);
+ page_kaddr = kmap_local_folio(folio, 0);
err = copy_from_user(page_kaddr,
(const void __user *) src_addr,
PAGE_SIZE);
@@ -659,10 +658,10 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
err = -EFAULT;
goto out;
}
- flush_dcache_page(page);
+ flush_dcache_folio(folio);
goto retry;
} else
- BUG_ON(page);
+ BUG_ON(folio);
if (!err) {
dst_addr += PAGE_SIZE;
@@ -679,8 +678,8 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
out_unlock:
mmap_read_unlock(dst_mm);
out:
- if (page)
- put_page(page);
+ if (folio)
+ folio_put(folio);
BUG_ON(copied < 0);
BUG_ON(err > 0);
BUG_ON(!copied && !err);
--
2.25.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
2023-03-14 3:37 ` [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() " Peng Zhang
@ 2023-03-14 8:31 ` Matthew Wilcox
2023-03-14 11:47 ` zhangpeng (AS)
0 siblings, 1 reply; 6+ messages in thread
From: Matthew Wilcox @ 2023-03-14 8:31 UTC (permalink / raw)
To: Peng Zhang
Cc: linux-mm, linux-kernel, akpm, mike.kravetz, vishal.moola,
sidhartha.kumar, wangkefeng.wang, sunnanyong
On Tue, Mar 14, 2023 at 03:37:33AM +0000, Peng Zhang wrote:
> +++ b/include/linux/mm.h
> @@ -3546,9 +3546,8 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
> unsigned long addr_hint,
> struct vm_area_struct *vma,
> unsigned int pages_per_huge_page);
> -extern long copy_huge_page_from_user(struct page *dst_page,
> +extern long copy_large_folio_from_user(struct folio *dst_folio,
You can drop the 'extern'.
> +++ b/mm/memory.c
> @@ -5769,26 +5769,28 @@ void copy_user_huge_page(struct page *dst, struct page *src,
> process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
> }
>
> -long copy_huge_page_from_user(struct page *dst_page,
> +long copy_large_folio_from_user(struct folio *dst_folio,
> const void __user *usr_src,
> - unsigned int pages_per_huge_page,
> bool allow_pagefault)
> {
> void *page_kaddr;
> unsigned long i, rc = 0;
> - unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
> + unsigned int nr_pages = folio_nr_pages(dst_folio);
> + unsigned long ret_val = nr_pages * PAGE_SIZE;
> struct page *subpage;
> + struct folio *inner_folio;
What is an 'inner folio'?
> - for (i = 0; i < pages_per_huge_page; i++) {
> - subpage = nth_page(dst_page, i);
> + for (i = 0; i < nr_pages; i++) {
> + subpage = folio_page(dst_folio, i);
> + inner_folio = page_folio(subpage);
> if (allow_pagefault)
> - page_kaddr = kmap(subpage);
> + page_kaddr = kmap_local_folio(inner_folio, 0);
This doesn't do what you think it does. Did you test this?
> else
> page_kaddr = kmap_atomic(subpage);
Pretty sure all this should be converted to kmap_local and the atomic
bits should go away.
> rc = copy_from_user(page_kaddr,
> usr_src + i * PAGE_SIZE, PAGE_SIZE);
> if (allow_pagefault)
> - kunmap(subpage);
> + kunmap_local(page_kaddr);
> else
> kunmap_atomic(page_kaddr);
>
> @@ -5796,7 +5798,7 @@ long copy_huge_page_from_user(struct page *dst_page,
> if (rc)
> break;
>
> - flush_dcache_page(subpage);
> + flush_dcache_folio(inner_folio);
The flush should probably be pulled outside the loop.
> + err = copy_large_folio_from_user(folio,
> + (const void __user *) src_addr, true);
I wonder if this shouldn't be 'copy_folio_from_user()'. after all,
it'll work for any size folio, right?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
2023-03-14 8:31 ` Matthew Wilcox
@ 2023-03-14 11:47 ` zhangpeng (AS)
0 siblings, 0 replies; 6+ messages in thread
From: zhangpeng (AS) @ 2023-03-14 11:47 UTC (permalink / raw)
To: Matthew Wilcox
Cc: linux-mm, linux-kernel, akpm, mike.kravetz, vishal.moola,
sidhartha.kumar, wangkefeng.wang, sunnanyong
On 2023/3/14 16:31, Matthew Wilcox wrote:
> On Tue, Mar 14, 2023 at 03:37:33AM +0000, Peng Zhang wrote:
>> +++ b/include/linux/mm.h
>> @@ -3546,9 +3546,8 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
>> unsigned long addr_hint,
>> struct vm_area_struct *vma,
>> unsigned int pages_per_huge_page);
>> -extern long copy_huge_page_from_user(struct page *dst_page,
>> +extern long copy_large_folio_from_user(struct folio *dst_folio,
> You can drop the 'extern'.
Got it.
>> +++ b/mm/memory.c
>> @@ -5769,26 +5769,28 @@ void copy_user_huge_page(struct page *dst, struct page *src,
>> process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
>> }
>>
>> -long copy_huge_page_from_user(struct page *dst_page,
>> +long copy_large_folio_from_user(struct folio *dst_folio,
>> const void __user *usr_src,
>> - unsigned int pages_per_huge_page,
>> bool allow_pagefault)
>> {
>> void *page_kaddr;
>> unsigned long i, rc = 0;
>> - unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
>> + unsigned int nr_pages = folio_nr_pages(dst_folio);
>> + unsigned long ret_val = nr_pages * PAGE_SIZE;
>> struct page *subpage;
>> + struct folio *inner_folio;
> What is an 'inner folio'?
>
>> - for (i = 0; i < pages_per_huge_page; i++) {
>> - subpage = nth_page(dst_page, i);
>> + for (i = 0; i < nr_pages; i++) {
>> + subpage = folio_page(dst_folio, i);
>> + inner_folio = page_folio(subpage);
>> if (allow_pagefault)
>> - page_kaddr = kmap(subpage);
>> + page_kaddr = kmap_local_folio(inner_folio, 0);
> This doesn't do what you think it does. Did you test this?
>
>> else
>> page_kaddr = kmap_atomic(subpage);
> Pretty sure all this should be converted to kmap_local and the atomic
> bits should go away.
>
>> rc = copy_from_user(page_kaddr,
>> usr_src + i * PAGE_SIZE, PAGE_SIZE);
>> if (allow_pagefault)
>> - kunmap(subpage);
>> + kunmap_local(page_kaddr);
>> else
>> kunmap_atomic(page_kaddr);
>>
>> @@ -5796,7 +5798,7 @@ long copy_huge_page_from_user(struct page *dst_page,
>> if (rc)
>> break;
>>
>> - flush_dcache_page(subpage);
>> + flush_dcache_folio(inner_folio);
> The flush should probably be pulled outside the loop.
>
>> + err = copy_large_folio_from_user(folio,
>> + (const void __user *) src_addr, true);
> I wonder if this shouldn't be 'copy_folio_from_user()'. after all,
> it'll work for any size folio, right?
Thanks for your review.
I'll rename copy_large_folio_from_user() to copy_folio_from_user().
I'll delete the inner_folio. kmap() and kmap_atomic() will be
converted to the following code.
page_kaddr = kmap_local_page(subpage);
if (!allow_pagefault)
pagefault_disable();
rc = copy_from_user(page_kaddr,
usr_src + i * PAGE_SIZE, PAGE_SIZE);
if (!allow_pagefault)
pagefault_enable();
kunmap_local(page_kaddr);
flush_dcache_folio() will be placed outside the loop.
I'll fix all this in a v2 of this patch series.
Thanks,
Peng.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-03-14 11:47 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-03-14 3:37 [PATCH 0/3] userfaultfd: convert userfaultfd functions to use folios Peng Zhang
2023-03-14 3:37 ` [PATCH 1/3] userfaultfd: convert mcopy_atomic_pte() to use a folio Peng Zhang
2023-03-14 3:37 ` [PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() " Peng Zhang
2023-03-14 8:31 ` Matthew Wilcox
2023-03-14 11:47 ` zhangpeng (AS)
2023-03-14 3:37 ` [PATCH 3/3] userfaultfd: convert __mcopy_atomic() " Peng Zhang
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