All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: Sarthak Sharma <sarthak.sharma@arm.com>
Cc: David Hildenbrand <david@kernel.org>,
	Jason Gunthorpe <jgg@ziepe.ca>,
	John Hubbard <jhubbard@nvidia.com>, Peter Xu <peterx@redhat.com>,
	Kiryl Shutsemau <kas@kernel.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm/gup_test: report actual pinned bytes
Date: Mon, 31 Aug 2026 17:12:05 -0700	[thread overview]
Message-ID: <20260831171205.9463e83d82da2a0b403da26a@linux-foundation.org> (raw)
In-Reply-To: <20260831101304.162867-1-sarthak.sharma@arm.com>

On Mon, 31 Aug 2026 15:43:04 +0530 Sarthak Sharma <sarthak.sharma@arm.com> wrote:

> __gup_test_ioctl() advances addr to the end of the current batch before
> checking if GUP pinned the entire requested batch. If GUP pins more than
> 0 pages but less than the requested batch size, addr still advances by
> the requested batch size.
> 
> The next iteration detects the partial pinning and breaks out of the loop.
> Again gup->size is calculated using addr - gup->addr, so it also includes
> the unpinned pages of the requested batch.
> 
> Calculate gup->size using the actual number of pages pinned multiplied
> by PAGE_SIZE.

Thanks.  Sashiko might have found a somewhat-related overflow on
32-bit.  Maybe fix that while we're in there?

	https://sashiko.dev/#/patchset/20260831101304.162867-1-sarthak.sharma@arm.com


  reply	other threads:[~2026-09-01  0:12 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-31 10:13 [PATCH v2] mm/gup_test: report actual pinned bytes Sarthak Sharma
2026-09-01  0:12 ` Andrew Morton [this message]
2026-09-07 13:44 ` David Hildenbrand (Arm)

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=20260831171205.9463e83d82da2a0b403da26a@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=david@kernel.org \
    --cc=jgg@ziepe.ca \
    --cc=jhubbard@nvidia.com \
    --cc=kas@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=peterx@redhat.com \
    --cc=sarthak.sharma@arm.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.