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Wed, 27 May 2020 22:32:46 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Wed, 27 May 2020 22:32:46 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.87.74]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Wed, 27 May 2020 15:32:45 -0700 From: John Hubbard To: Andrew Morton CC: LKML , , John Hubbard Subject: [PATCH 2/2] mm/gup: frame_vector: convert get_user_pages() --> pin_user_pages() Date: Wed, 27 May 2020 15:32:43 -0700 Message-ID: <20200527223243.884385-3-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200527223243.884385-1-jhubbard@nvidia.com> References: <20200527223243.884385-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1590618683; bh=sWvJDniuNa0MloWGBo3nO/qwt/IUY5Pd+BokGdPrg7M=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; 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That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Signed-off-by: John Hubbard --- mm/frame_vector.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/frame_vector.c b/mm/frame_vector.c index c431ca81dad5..4107dbca0056 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -72,7 +72,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { vec->got_ref = true; vec->is_pfns = false; - ret = get_user_pages_locked(start, nr_frames, + ret = pin_user_pages_locked(start, nr_frames, gup_flags, (struct page **)(vec->ptrs), &locked); goto out; } @@ -122,7 +122,6 @@ EXPORT_SYMBOL(get_vaddr_frames); */ void put_vaddr_frames(struct frame_vector *vec) { - int i; struct page **pages; if (!vec->got_ref) @@ -135,8 +134,8 @@ void put_vaddr_frames(struct frame_vector *vec) */ if (WARN_ON(IS_ERR(pages))) goto out; - for (i = 0; i < vec->nr_frames; i++) - put_page(pages[i]); + + unpin_user_pages(pages, vec->nr_frames); vec->got_ref = false; out: vec->nr_frames = 0;