linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	akpm@linux-foundation.org, songmuchun@bytedance.com,
	mike.kravetz@oracle.com, jhubbard@nvidia.com
Subject: Re: [PATCH 2/9] mm/hugetlb: convert hugetlbfs_pagecache_present() to folios
Date: Fri, 20 Jan 2023 05:43:44 +0000	[thread overview]
Message-ID: <Y8oqEOICcNV762IA@casper.infradead.org> (raw)
In-Reply-To: <20230119211446.54165-3-sidhartha.kumar@oracle.com>

On Thu, Jan 19, 2023 at 01:14:39PM -0800, Sidhartha Kumar wrote:
> +++ b/mm/hugetlb.c
> @@ -5653,15 +5653,15 @@ static bool hugetlbfs_pagecache_present(struct hstate *h,
>  {
>  	struct address_space *mapping;
>  	pgoff_t idx;
> -	struct page *page;
> +	struct folio *folio;
>  
>  	mapping = vma->vm_file->f_mapping;
>  	idx = vma_hugecache_offset(h, vma, address);
>  
> -	page = find_get_page(mapping, idx);
> -	if (page)
> -		put_page(page);
> -	return page != NULL;
> +	folio = filemap_get_folio(mapping, idx);
> +	if (folio)
> +		folio_put(folio);
> +	return folio != NULL;
>  }

Seems to me this function could be ...

	struct address_space *mapping = vma->vm_file->f_mapping;
	pgoff_t index = vma_hugecache_offset(h, vma, address);
	bool present;

	rcu_read_lock();
	present = page_cache_next_miss(mapping, index, 1) != index;
	rcu_read_unlock();

	return present;

No need to get/drop a refcount on the folio.  It's a bit similar to
filemap_range_has_page(), but the API is wrong.  Maybe there's room
for a little refactoring here.


  reply	other threads:[~2023-01-20  5:43 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-19 21:14 [PATCH 0/9] convert hugetlb fault functions to folios Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 1/9] mm/hugetlb: convert hugetlb_install_page " Sidhartha Kumar
2023-01-20 23:21   ` Mike Kravetz
2023-01-19 21:14 ` [PATCH 2/9] mm/hugetlb: convert hugetlbfs_pagecache_present() " Sidhartha Kumar
2023-01-20  5:43   ` Matthew Wilcox [this message]
2023-01-20 23:40     ` Mike Kravetz
2023-01-19 21:14 ` [PATCH 3/9] mm/hugetlb: convert putback_active_hugepage to take in a folio Sidhartha Kumar
2023-01-20  5:48   ` Matthew Wilcox
2023-01-20 23:47   ` Mike Kravetz
2023-01-19 21:14 ` [PATCH 4/9] mm/rmap: change hugepage_add_new_anon_rmap " Sidhartha Kumar
2023-01-20  6:00   ` Matthew Wilcox
2023-01-20 20:45     ` Sidhartha Kumar
2023-01-20 21:17       ` Matthew Wilcox
2023-01-20 22:05         ` Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 5/9] mm/hugetlb: convert alloc_huge_page to alloc_hugetlb_folio Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 6/9] mm/hugetlb: convert restore_reserve_on_error to take in a folio Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 7/9] mm/hugetlb: convert hugetlb_add_to_page_cache " Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 8/9] mm/hugetlb: convert hugetlb_wp() " Sidhartha Kumar
2023-01-24 15:23   ` Gerald Schaefer
2023-01-24 18:38     ` Sidhartha Kumar
2023-01-19 21:14 ` [PATCH 9/9] Documentation/mm: update hugetlbfs documentation to mention alloc_hugetlb_folio Sidhartha Kumar

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=Y8oqEOICcNV762IA@casper.infradead.org \
    --to=willy@infradead.org \
    --cc=akpm@linux-foundation.org \
    --cc=jhubbard@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mike.kravetz@oracle.com \
    --cc=sidhartha.kumar@oracle.com \
    --cc=songmuchun@bytedance.com \
    /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).