All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Wilcox <willy@infradead.org>
To: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Jens Axboe <axboe@kernel.dk>,
	io-uring@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH v2 10/13] mm: Free up a word in the first tail page
Date: Wed, 23 Aug 2023 01:29:55 +0100	[thread overview]
Message-ID: <ZOVTAxzuzzOpCy2q@casper.infradead.org> (raw)
In-Reply-To: <20230822231741.GC4509@monkey>

On Tue, Aug 22, 2023 at 04:17:41PM -0700, Mike Kravetz wrote:
> On 08/16/23 16:11, Matthew Wilcox (Oracle) wrote:
> > Store the folio order in the low byte of the flags word in the first
> > tail page.  This frees up the word that was being used to store the
> > order and dtor bytes previously.
> 
> hugetlb manually creates and destroys compound pages.  As such it makes
> assumptions about struct page layout.  This breaks hugetlb.  The following
> will allow fix the breakage.
> 
> The hugetlb code is quite fragile when changes like this are made.  I am
> open to suggestions on how we can make this more robust.  Perhaps start
> with a simple set of APIs to create_folio from a set of contiguous pages
> and destroy a folio?

Thanks; those changes look good to me.

I don't have any _immediate_ plans to make your life easier.  When
we get to a memdesc world, it'll all get much easier.

  reply	other threads:[~2023-08-23  0:30 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-16 15:11 [PATCH v2 00/13] Remove _folio_dtor and _folio_order Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 01/13] io_uring: Stop calling free_compound_page() Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 02/13] mm: Call free_huge_page() directly Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 03/13] mm: Convert free_huge_page() to free_huge_folio() Matthew Wilcox (Oracle)
2023-08-16 20:14   ` Sidhartha Kumar
2023-08-17  3:31   ` Yanteng Si
2023-08-16 15:11 ` [PATCH v2 04/13] mm: Convert free_transhuge_folio() to folio_undo_large_rmappable() Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 05/13] mm; Convert prep_transhuge_page() to folio_prep_large_rmappable() Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 06/13] mm: Remove free_compound_page() and the compound_page_dtors array Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 07/13] mm: Remove HUGETLB_PAGE_DTOR Matthew Wilcox (Oracle)
2023-08-16 21:45   ` Sidhartha Kumar
2023-08-22  3:13   ` Mike Kravetz
2023-08-22  3:32     ` Matthew Wilcox
2023-08-22 17:19       ` Mike Kravetz
2023-12-08 17:54   ` Vlastimil Babka
2023-12-08 18:31     ` Matthew Wilcox
2023-12-13 12:23       ` David Hildenbrand
2023-08-16 15:11 ` [PATCH v2 08/13] mm: Add large_rmappable page flag Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 09/13] mm: Rearrange page flags Matthew Wilcox (Oracle)
2023-08-16 15:11 ` [PATCH v2 10/13] mm: Free up a word in the first tail page Matthew Wilcox (Oracle)
2023-08-22 23:17   ` Mike Kravetz
2023-08-23  0:29     ` Matthew Wilcox [this message]
2023-08-16 15:11 ` [PATCH v2 11/13] mm: Remove folio_test_transhuge() Matthew Wilcox (Oracle)
2023-08-16 15:12 ` [PATCH v2 12/13] mm: Add tail private fields to struct folio Matthew Wilcox (Oracle)
2023-08-16 15:21   ` David Hildenbrand
2023-08-16 15:12 ` [PATCH v2 13/13] mm: Convert split_huge_pages_pid() to use a folio Matthew Wilcox (Oracle)

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=ZOVTAxzuzzOpCy2q@casper.infradead.org \
    --to=willy@infradead.org \
    --cc=akpm@linux-foundation.org \
    --cc=axboe@kernel.dk \
    --cc=io-uring@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mike.kravetz@oracle.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 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.