LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Yang Shi <shy828301@gmail.com>
To: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Shakeel Butt <shakeelb@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Michal Hocko <mhocko@suse.com>, Rik van Riel <riel@surriel.com>,
Matthew Wilcox <willy@infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux MM <linux-mm@kvack.org>
Subject: Re: [PATCH 7/9] huge tmpfs: shmem_is_huge(vma, inode, index)
Date: Tue, 17 Aug 2021 13:16:12 -0700 [thread overview]
Message-ID: <CAHbLzkrFTxLb6jmfQBvGdnOHCAc8d8Y21c0TniHGGkVZOLPpdw@mail.gmail.com> (raw)
In-Reply-To: <23a77889-2ddc-b030-75cd-44ca27fd4d1@google.com>
On Tue, Aug 17, 2021 at 1:19 AM Hugh Dickins <hughd@google.com> wrote:
>
> Extend shmem_huge_enabled(vma) to shmem_is_huge(vma, inode, index), so
> that a consistent set of checks can be applied, even when the inode is
> accessed through read/write syscalls (with NULL vma) instead of mmaps
> (the index argument is seldom of interest, but required by mount option
> "huge=within_size"). Clean up and rearrange the checks a little.
>
> This then replaces the checks which shmem_fault() and shmem_getpage_gfp()
> were making, and eliminates the SGP_HUGE and SGP_NOHUGE modes.
>
> Replace a couple of 0s by explicit SHMEM_HUGE_NEVERs; and replace the
> obscure !shmem_mapping() symlink check by explicit S_ISLNK() - nothing
> else needs that symlink check, so leave it there in shmem_getpage_gfp().
>
> Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
> ---
> include/linux/shmem_fs.h | 9 +++--
> mm/shmem.c | 84 ++++++++++++----------------------------
> 2 files changed, 31 insertions(+), 62 deletions(-)
>
> diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
> index 7d97b15a2f7a..60c6e4eac275 100644
> --- a/include/linux/shmem_fs.h
> +++ b/include/linux/shmem_fs.h
> @@ -86,7 +86,12 @@ extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
> extern int shmem_unuse(unsigned int type, bool frontswap,
> unsigned long *fs_pages_to_unuse);
>
> -extern bool shmem_huge_enabled(struct vm_area_struct *vma);
> +extern bool shmem_is_huge(struct vm_area_struct *vma,
> + struct inode *inode, pgoff_t index);
> +static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
> +{
> + return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff);
> +}
> extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
> extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
> pgoff_t start, pgoff_t end);
> @@ -96,8 +101,6 @@ enum sgp_type {
> SGP_READ, /* don't exceed i_size, don't allocate page */
> SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */
> SGP_CACHE, /* don't exceed i_size, may allocate page */
> - SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */
> - SGP_HUGE, /* like SGP_CACHE, huge pages preferred */
> SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
> SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
> };
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 226ac3a911e9..56ee56b1cab6 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -474,39 +474,35 @@ static bool shmem_confirm_swap(struct address_space *mapping,
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> /* ifdef here to avoid bloating shmem.o when not necessary */
>
> -static int shmem_huge __read_mostly;
> +static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER;
>
> -bool shmem_huge_enabled(struct vm_area_struct *vma)
> +bool shmem_is_huge(struct vm_area_struct *vma,
> + struct inode *inode, pgoff_t index)
> {
> - struct inode *inode = file_inode(vma->vm_file);
> - struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
> loff_t i_size;
> - pgoff_t off;
>
> - if ((vma->vm_flags & VM_NOHUGEPAGE) ||
> - test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> - return false;
> - if (shmem_huge == SHMEM_HUGE_FORCE)
> - return true;
> if (shmem_huge == SHMEM_HUGE_DENY)
> return false;
> - switch (sbinfo->huge) {
> - case SHMEM_HUGE_NEVER:
> + if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
> + test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
> return false;
> + if (shmem_huge == SHMEM_HUGE_FORCE)
> + return true;
> +
> + switch (SHMEM_SB(inode->i_sb)->huge) {
> case SHMEM_HUGE_ALWAYS:
> return true;
> case SHMEM_HUGE_WITHIN_SIZE:
> - off = round_up(vma->vm_pgoff, HPAGE_PMD_NR);
> + index = round_up(index, HPAGE_PMD_NR);
> i_size = round_up(i_size_read(inode), PAGE_SIZE);
> - if (i_size >= HPAGE_PMD_SIZE &&
> - i_size >> PAGE_SHIFT >= off)
> + if (i_size >= HPAGE_PMD_SIZE && (i_size >> PAGE_SHIFT) >= index)
> return true;
> fallthrough;
> case SHMEM_HUGE_ADVISE:
> - /* TODO: implement fadvise() hints */
> - return (vma->vm_flags & VM_HUGEPAGE);
> + if (vma && (vma->vm_flags & VM_HUGEPAGE))
> + return true;
> + fallthrough;
> default:
> - VM_BUG_ON(1);
> return false;
> }
> }
> @@ -680,6 +676,12 @@ static long shmem_unused_huge_count(struct super_block *sb,
>
> #define shmem_huge SHMEM_HUGE_DENY
>
> +bool shmem_is_huge(struct vm_area_struct *vma,
> + struct inode *inode, pgoff_t index)
> +{
> + return false;
> +}
> +
> static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
> struct shrink_control *sc, unsigned long nr_to_split)
> {
> @@ -1829,7 +1831,6 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
> struct shmem_sb_info *sbinfo;
> struct mm_struct *charge_mm;
> struct page *page;
> - enum sgp_type sgp_huge = sgp;
> pgoff_t hindex = index;
> gfp_t huge_gfp;
> int error;
> @@ -1838,8 +1839,6 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
>
> if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
> return -EFBIG;
> - if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
> - sgp = SGP_CACHE;
> repeat:
> if (sgp <= SGP_CACHE &&
> ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
> @@ -1903,36 +1902,12 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
> return 0;
> }
>
> - /* shmem_symlink() */
> - if (!shmem_mapping(mapping))
> - goto alloc_nohuge;
> - if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
> + /* Never use a huge page for shmem_symlink() */
> + if (S_ISLNK(inode->i_mode))
> goto alloc_nohuge;
> - if (shmem_huge == SHMEM_HUGE_FORCE)
> - goto alloc_huge;
> - switch (sbinfo->huge) {
> - case SHMEM_HUGE_NEVER:
> + if (!shmem_is_huge(vma, inode, index))
> goto alloc_nohuge;
> - case SHMEM_HUGE_WITHIN_SIZE: {
> - loff_t i_size;
> - pgoff_t off;
> -
> - off = round_up(index, HPAGE_PMD_NR);
> - i_size = round_up(i_size_read(inode), PAGE_SIZE);
> - if (i_size >= HPAGE_PMD_SIZE &&
> - i_size >> PAGE_SHIFT >= off)
> - goto alloc_huge;
>
> - fallthrough;
> - }
> - case SHMEM_HUGE_ADVISE:
> - if (sgp_huge == SGP_HUGE)
> - goto alloc_huge;
> - /* TODO: implement fadvise() hints */
> - goto alloc_nohuge;
> - }
> -
> -alloc_huge:
> huge_gfp = vma_thp_gfp_mask(vma);
> huge_gfp = limit_gfp_mask(huge_gfp, gfp);
> page = shmem_alloc_and_acct_page(huge_gfp, inode, index, true);
> @@ -2088,7 +2063,6 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
> struct vm_area_struct *vma = vmf->vma;
> struct inode *inode = file_inode(vma->vm_file);
> gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
> - enum sgp_type sgp;
> int err;
> vm_fault_t ret = VM_FAULT_LOCKED;
>
> @@ -2151,15 +2125,7 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
> spin_unlock(&inode->i_lock);
> }
>
> - sgp = SGP_CACHE;
> -
> - if ((vma->vm_flags & VM_NOHUGEPAGE) ||
> - test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
> - sgp = SGP_NOHUGE;
> - else if (vma->vm_flags & VM_HUGEPAGE)
> - sgp = SGP_HUGE;
> -
> - err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
> + err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE,
> gfp, vma, vmf, &ret);
> if (err)
> return vmf_error(err);
> @@ -3966,7 +3932,7 @@ int __init shmem_init(void)
> if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
> SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
> else
> - shmem_huge = 0; /* just in case it was patched */
> + shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */
> #endif
> return 0;
>
> --
> 2.26.2
>
next prev parent reply other threads:[~2021-08-17 20:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 8:03 [PATCH 0/9] huge tmpfs: shmem_is_huge() fixes and cleanups Hugh Dickins
2021-08-17 8:06 ` [PATCH 1/9] huge tmpfs: fix fallocate(vanilla) advance over huge pages Hugh Dickins
2021-08-17 8:08 ` [PATCH 2/9] huge tmpfs: fix split_huge_page() after FALLOC_FL_KEEP_SIZE Hugh Dickins
2021-08-17 8:10 ` [PATCH 3/9] huge tmpfs: remove shrinklist addition from shmem_setattr() Hugh Dickins
2021-08-17 8:12 ` [PATCH 4/9] huge tmpfs: revert shmem's use of transhuge_vma_enabled() Hugh Dickins
2021-08-17 8:14 ` [PATCH 5/9] huge tmpfs: move shmem_huge_enabled() upwards Hugh Dickins
2021-08-17 8:17 ` [PATCH 6/9] huge tmpfs: SGP_NOALLOC to stop collapse_file() on race Hugh Dickins
2021-08-17 20:14 ` Yang Shi
2021-08-17 8:19 ` [PATCH 7/9] huge tmpfs: shmem_is_huge(vma, inode, index) Hugh Dickins
2021-08-17 20:16 ` Yang Shi [this message]
2021-08-17 8:22 ` [PATCH 8/9] huge tmpfs: decide stat.st_blksize by shmem_is_huge() Hugh Dickins
2021-08-17 8:28 ` [PATCH 9/9] shmem: shmem_writepage() split unlikely i915 THP Hugh Dickins
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAHbLzkrFTxLb6jmfQBvGdnOHCAc8d8Y21c0TniHGGkVZOLPpdw@mail.gmail.com \
--to=shy828301@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=hughd@google.com \
--cc=kirill.shutemov@linux.intel.com \
--cc=linmiaohe@huawei.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=mike.kravetz@oracle.com \
--cc=riel@surriel.com \
--cc=shakeelb@google.com \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).