Re: [PATCH v2 03/17] mm/rmap: convert make_device_exclusive_range() to make_device_exclusive()
From: Alistair Popple <apopple@nvidia.com>
Date: 2025-02-17 00:01:56
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damon, dri-devel, linux-doc, linux-mm, linux-perf-users, lkml, nouveau
On Tue, Feb 11, 2025 at 09:33:54AM +0100, David Hildenbrand wrote:
On 11.02.25 06:00, Andrew Morton wrote:quoted
On Mon, 10 Feb 2025 20:37:45 +0100 David Hildenbrand [off-list ref] wrote:quoted
The single "real" user in the tree of make_device_exclusive_range() always requests making only a single address exclusive. The current implementation is hard to fix for properly supporting anonymous THP / large folios and for avoiding messing with rmap walks in weird ways. So let's always process a single address/page and return folio + page to minimize page -> folio lookups. This is a preparation for further changes. Reject any non-anonymous or hugetlb folios early, directly after GUP. While at it, extend the documentation of make_device_exclusive() to clarify some things.x86_64 allmodconfig: drivers/gpu/drm/nouveau/nouveau_svm.c: In function 'nouveau_atomic_range_fault': drivers/gpu/drm/nouveau/nouveau_svm.c:612:68: error: 'folio' undeclared (first use in this function) 612 | page = make_device_exclusive(mm, start, drm->dev, &folio); | ^~~~~ drivers/gpu/drm/nouveau/nouveau_svm.c:612:68: note: each undeclared identifier is reported only once for each function it appears inAh! Because I was carrying on the same branch SVM fixes [1] that are getting surprisingly little attention so far.
I believe this has been picked up in drm-misc-fixes now: https://lore.kernel.org/dri-devel/Z69eloo_7LM6NneO@cassiopeiae/ (local)
quoted hunk ↗ jump to hunk
The following sorts it out for now: From 337c68bf24af59f36477be11ea6ef7c7ce9aa8ae Mon Sep 17 00:00:00 2001 From: David Hildenbrand <redacted> Date: Tue, 11 Feb 2025 09:33:04 +0100 Subject: [PATCH] merge Signed-off-by: David Hildenbrand <redacted> --- drivers/gpu/drm/nouveau/nouveau_svm.c | 1 + 1 file changed, 1 insertion(+)diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 39e3740980bb7..1fed638b9eba8 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c@@ -590,6 +590,7 @@ static int nouveau_atomic_range_fault(struct nouveau_svmm *svmm, unsigned long timeout = jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT); struct mm_struct *mm = svmm->notifier.mm; + struct folio *folio; struct page *page; unsigned long start = args->p.addr; unsigned long notifier_seq;-- 2.48.1 I'll resend [1] once this stuff here landed. Let me know if you want a full resend of this series, thanks. [1] https://lkml.kernel.org/r/20250124181524.3584236-1-david@redhat.com -- Cheers, David / dhildenb