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From: Jaewon Kim <jaewon31.kim@gmail.com>
To: zhaoyang.huang@unisoc.com, jhubbard@nvidia.com, david@redhat.com
Cc: surenb@google.com, linux-mm@kvack.org
Subject: [RFC] pin_user_pages_fast failure count increased
Date: Tue, 29 Apr 2025 00:17:02 +0900	[thread overview]
Message-ID: <CAJrd-UuAZ6oLLUKnOkTQjKYxSwtPk5noaUFrnNantM7yFiRVuw@mail.gmail.com> (raw)

Hi

If pin_user_pages_fast does not pin all the requested number of pages,
then drivers calling to pin_user_pages_fast should retry until the gup
pins all?

Our GPU driver uses pin_user_pages_fast.
After the recent kernel update, pin_user_pages_fast sometimes does not
pin all the pages, nr_pinned < nr_pages.

I think the following patch affected the pin_user_pages_fast behavior.
1aaf8c122918 mm: gup: fix infinite loop within __get_longterm_locked

BR
Jaewon Kim


             reply	other threads:[~2025-04-28 15:17 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-28 15:17 Jaewon Kim [this message]
2025-04-28 15:21 ` David Hildenbrand
2025-04-28 20:14 ` John Hubbard
2025-04-28 20:56   ` David Hildenbrand
2025-04-28 21:12     ` John Hubbard
     [not found]       ` <CGME20250522092944epcas2p1ca46168564555aad6d9880bda26ec8de@epcas2p1.samsung.com>
2025-05-22  9:27         ` Hyesoo Yu

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