All of lore.kernel.org
 help / color / mirror / Atom feed
From: James Houghton <jthoughton@google.com>
To: Mike Kravetz <mike.kravetz@oracle.com>,
	Hugh Dickins <hughd@google.com>,
	Muchun Song <songmuchun@bytedance.com>,
	Peter Xu <peterx@redhat.com>,
	"Matthew Wilcox (Oracle)" <willy@infradead.org>,
	Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>,
	David Hildenbrand <david@redhat.com>,
	David Rientjes <rientjes@google.com>,
	Axel Rasmussen <axelrasmussen@google.com>,
	Jiaqi Yan <jiaqiyan@google.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	James Houghton <jthoughton@google.com>
Subject: [PATCH 2/2] mm: rmap: increase COMPOUND_MAPPED to support 512G HugeTLB pages
Date: Mon,  6 Mar 2023 23:00:04 +0000	[thread overview]
Message-ID: <20230306230004.1387007-3-jthoughton@google.com> (raw)
In-Reply-To: <20230306230004.1387007-1-jthoughton@google.com>

Some architectures may want to support 512G HugeTLB pages in the future.
Adjust COMPOUND_MAPPED to support this page size.

Signed-off-by: James Houghton <jthoughton@google.com>

diff --git a/mm/internal.h b/mm/internal.h
index 400451a4dd49..994381fd5155 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -53,11 +53,11 @@ struct folio_batch;
 void page_writeback_init(void);
 
 /*
- * If a 16GB hugetlb folio were mapped by PTEs of all of its 4kB pages,
- * its nr_pages_mapped would be 0x400000: choose the COMPOUND_MAPPED bit
- * above that range, instead of 2*(PMD_SIZE/PAGE_SIZE).
+ * If a 512G hugetlb folio were mapped by PTEs of all of its 4kB pages,
+ * its nr_pages_mapped would be 2^27 (0x8000000): choose the COMPOUND_MAPPED bit
+ * above that range.
  */
-#define COMPOUND_MAPPED		0x800000
+#define COMPOUND_MAPPED		(1 << 28)
 #define FOLIO_PAGES_MAPPED	(COMPOUND_MAPPED - 1)
 
 /*
-- 
2.40.0.rc0.216.gc4246ad0f0-goog


  parent reply	other threads:[~2023-03-06 23:00 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-06 23:00 [PATCH 0/2] mm: rmap: merge HugeTLB mapcount logic with THPs James Houghton
2023-03-06 23:00 ` [PATCH 1/2] mm: rmap: make hugetlb pages participate in _nr_pages_mapped James Houghton
2023-03-07 21:54   ` Mike Kravetz
2023-03-08  0:36     ` James Houghton
2023-03-08 21:56       ` Peter Xu
2023-03-09 19:58         ` James Houghton
2023-03-06 23:00 ` James Houghton [this message]
2023-03-08 22:10 ` [PATCH 0/2] mm: rmap: merge HugeTLB mapcount logic with THPs Peter Xu
2023-03-09 18:05   ` James Houghton
2023-03-09 19:29     ` Peter Xu

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=20230306230004.1387007-3-jthoughton@google.com \
    --to=jthoughton@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=axelrasmussen@google.com \
    --cc=david@redhat.com \
    --cc=hughd@google.com \
    --cc=jiaqiyan@google.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mike.kravetz@oracle.com \
    --cc=peterx@redhat.com \
    --cc=rientjes@google.com \
    --cc=songmuchun@bytedance.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.