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b=kw1AZvYl9fsLLFDrf03thMZpapgwREV573+aQgtXJh/1L6MywmzdrV1OuJ7BHGQNH 8v5SgpSQfSOWTyOcwAMNseru5+3K6ksmtAzWkk8GpbPI8NNusgv492yCWXaaeuYUY8 rKsB43XM+GHowHoQOSxt9fdNDbtekWruf8UMGYefBB4paSz565+bNU/RMnhv9Ldwjc brX5s+dV2Nm+yBS5y6KTZLF6U+B3dD3TNe8Bp6CBYF8J0+80Ai9LK7K3WKu95nRtr5 d5yudcbvmB4UIQu6hbyjLzl7cZwBXn7TqxspmFCKLy9VpilG0EHAMDi/CpfJ/E8zBE Hft7HhitnW3gQ== Date: Mon, 27 Jul 2026 17:29:32 +0100 From: "Lorenzo Stoakes (ARM)" To: Hongfu Li Cc: akpm@linux-foundation.org, david@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hongfu Li Subject: Re: [PATCH v2 1/2] mm: Use a folio in the softleaf_is_device_private path Message-ID: References: <20260723030752.16979-1-hongfu.li@linux.dev> <20260723030752.16979-2-hongfu.li@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260723030752.16979-2-hongfu.li@linux.dev> X-Rspamd-Queue-Id: 804141C000C X-Rspam-User: X-Stat-Signature: buc4f33xapgktj6ddykkhismefopcwsj X-Rspamd-Server: rspam04 X-HE-Tag: 1785169790-62857 X-HE-Meta: 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 NoU6o3/f GgSYnJyWPMfUwSMtYkY4EYTEKpeeDZcnGrfLxGa3BrqEVN6zJfz32tdf10CxI3ffHu8F2OZVK1HmAXmdjOCRvHyMggto00lZgmHf0ERF8rM+012KZj89h/2Xn8gflFhOMHYzyldWgh2t4wWJvNz3+qSJswTr35xGsQ7r/gKqo52f0nzITPRE0mWxKdn6fDj/2Rto5rfydnlRGsdcHG1Rb6UXGFxCangwSXsPrhGpNPW/8ercKUG8Y+rwm6TC3LrljwvJV2fgEdPUzz9K1eN8nAw7ILZl8JQQqIvfyG29+6XZGwzbnJkRvVDizBHOI9m329SOqxres4lXsR992LP8/Si9buVg1P0wwuj7D Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jul 23, 2026 at 11:07:51AM +0800, Hongfu Li wrote: > From: Hongfu Li > > Use the folio APIs in the device_private migration path of do_swap_page(), > replacing four calls to compound_head() with one. > > Signed-off-by: Hongfu Li > Acked-by: David Hildenbrand (Arm) With changes below applied LGTM, so: Reviewed-by: Lorenzo Stoakes (ARM) > --- > mm/memory.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index d5e87624f692..ae521baa8c84 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -4871,18 +4871,19 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > goto unlock; > Up here we have: vmf->page = softleaf_to_page(entry); vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); if (unlikely(!vmf->pte || !pte_same(ptep_get(vmf->pte), vmf->orig_pte))) Since we're canonicalising to folio why not actually set folio using softleaf_to_folio()? So + folio = softleaf_to_folio(entry); - vmf->page = softleaf_to_page(entry); + vmf->page = &folio->page; This would also make more sense in your 2/2. But more on that in a sec. > /* > - * Get a page reference while we know the page can't be > + * Get a folio reference while we know the folio can't be NIT: be -> next line for 80 chars. > * freed. > */ > - if (trylock_page(vmf->page)) { > + folio = page_folio(vmf->page); > + if (folio_trylock(folio)) { > struct dev_pagemap *pgmap; > > - get_page(vmf->page); > + folio_get(folio); > pte_unmap_unlock(vmf->pte, vmf->ptl); > pgmap = page_pgmap(vmf->page); > ret = pgmap->ops->migrate_to_ram(vmf); > - unlock_page(vmf->page); > - put_page(vmf->page); > + folio_unlock(folio); > + folio_put(folio); > } else { > pte_unmap(vmf->pte); > softleaf_entry_wait_on_locked(entry, vmf->ptl); > -- > 2.54.0 > Thanks, Lorenzo