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b=I/TpK4bl98aV/sTC1haCa4Cuuak2SE+h1ZI1AB4DfIJfpaF8O8dA2+dHUGYJ9HC+R S2sendxfqPps6CZQDi12lE3ER1ez+BSXCqZWvDJjKM4P2e3dQbDYF8BU1bj1LGON6O 99JffUSLFzaYX4pZV5Sl60+GbL2D1+TFKWcYu/2nAx01TN58NA7mVrXcXby4n3NNwR iPJN64ZmkW8Jae5bYGXdouEfnhIYJWxZ8KQRXK+A0afpQ0QAILJ1WYY+qzlVy4wEaj N4644hTWHCqS/F2bLPu6CvDW8c5A0YSznOaRGm0dhKKENzI2njlBQ2KitJyQDUrsD4 CVd5dBamh0fLg== Date: Tue, 12 May 2026 16:46:14 +0100 From: Lorenzo Stoakes To: Minu Jin 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 Subject: Re: [PATCH] mm: fix misleading comment for remap_pfn_range() Message-ID: References: <20260512143543.258399-1-s9430939@naver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260512143543.258399-1-s9430939@naver.com> X-Rspam-User: X-Rspamd-Queue-Id: D3B5240012 X-Rspamd-Server: rspam06 X-Stat-Signature: qtfsjrh6pn37szpe7u7s5woyqdap1c6r X-HE-Tag: 1778600780-883222 X-HE-Meta: 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 YH6y0vgW 5Y0MfgLsR0Xi3CaTathtp3jEJDHCmGrMfk6LnLfL7xL0Kq2r4CnicIhiszBU6zviwytjwGCDHCOH5Aa9TjGxgrqiEZnYLcUaI3VEZmA5mYNtvLPy/iLrShJoKzYUA70//huQ54td5SKg1tTMNGVFAbBp/RAVLuOMARUC9zANuC5OOI2ex/aK8eaEAvjwG//lmMvQSl2qXETxXrc4x8wvrneaNwPpYfpXt7omq8S2an1w6QRV1hZ7by7+2S8eGzcXZkXAiKAgP4DKF6H1t2KUuCU+f6MKctPkYYPghGkSkrozgRhfbGAwTiCK1/vGPbhjZ85lP Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, May 12, 2026 at 11:35:43PM +0900, Minu Jin wrote: > The function summary describes this as remapping "kernel memory", > but remap_pfn_range() operates on arbitrary PFNs, including > device MMIO regions that are not kernel memory at all. > > Replace with "physical address range". > It describes accurately what the function maps. > > Signed-off-by: Minu Jin Hm, arguably those are 'kernel' memory in some sense. And 'physical address range' is a little confusing vs. PFN's as PFN's != physical addresses. Also remap_pfn_range() is, in effect, a deprecated function as we move drivers to using mmap_prepare equivalents (implemented in remap_pfn_range_prepare()) so I'm not sure it's really worth updating? > --- > mm/memory.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/memory.c b/mm/memory.c > index ea6568571131..4e07e03a76a4 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3172,7 +3172,7 @@ static int remap_pfn_range_prepare_vma(struct vm_area_struct *vma, > } > > /** > - * remap_pfn_range - remap kernel memory to userspace > + * remap_pfn_range - remap physical address range to user space > * @vma: user vma to map to > * @addr: target page aligned user address to start at > * @pfn: page frame number of kernel physical memory address > -- > 2.43.0 > Cheers, Lorenzo