From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E540A3FBB3 for ; Mon, 15 Sep 2025 22:45:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757976360; cv=none; b=d4CI5oMErbh6OJZstGtSWPZaQteo0eqZM247yLTTfhRUgxrHFh/G29olUhVLLXdUuujTrqB3jB21VfvQwu/+WrrG0shig8hYnqeoxTGD5jLrKOolml675B+wdjmCtpQZkzGgnwqQ3iNdEF3ypubYs2wXWOK7QMLxsq+EVIuZPkE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757976360; c=relaxed/simple; bh=L11pY/CJ6RdF5UkY2ZaMbNvRPq4z4ORUDX+hzUijP3Y=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pGl/BM9+yhYO4ia5rMhA8mjmLsEwNlJT9BtHEvGNxhBZu6Nq2s7ysc9ZtAUmevQKEjxu9eW8wjV/V7f79KTPLX9ZVIrDHrS8fTZo3TmaEXJFvDu97TPjJd+++9BdjIwzvJylxteThT5Exb6m3oxMGsHEtAB9kwSAngaE+y3cILw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=TKEajOOi; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TKEajOOi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1757976358; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=uR14VGW0/X0AylQCvnqkHSqGmKvFKN2TXdGehzTWgbM=; b=TKEajOOiZtWRpksuhXcoKpQ0nH6KUffwT0kgP/mhWBSbnQ+1m7lEpsvm3DJ4Lde6EKI58S TQM6QhmIGKL9hqgggFx08oFJz4cbWZaBC7EWG0p9v1OSNTqpz4oM29HrMDlsxhMOJux3v4 pm90ChZr7QTpYR2xdNlYS013xS8wef0= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-457-yDnd-uL3MG6xwnZuuZTa2A-1; Mon, 15 Sep 2025 18:45:56 -0400 X-MC-Unique: yDnd-uL3MG6xwnZuuZTa2A-1 X-Mimecast-MFC-AGG-ID: yDnd-uL3MG6xwnZuuZTa2A_1757976355 Received: by mail-ed1-f69.google.com with SMTP id 4fb4d7f45d1cf-6215564bf48so4319222a12.0 for ; Mon, 15 Sep 2025 15:45:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757976355; x=1758581155; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=uR14VGW0/X0AylQCvnqkHSqGmKvFKN2TXdGehzTWgbM=; b=gXyGvoItCgrdKxEvcYTulYt2DftPoM8OYsU1up0UGEZfyxVf4nGh1m/i7vofZ/oH7N GrcR4ZtcW3kLe88GLk3NcBBQAzdgG7RumySrSVJa9vEgVHbiKfoqtEKrrnuYVQRyEr6P YjBqJ7UPWms4NGCjR1MYnOCrSi7ILMzcY5/ukUbc4+DMM+poeorgJKSOWGCWJ1v+Xgf0 /X96Tg8G+YVkHGHuZ0ELNpYt9U/ofSIESG40utgb7zFJVUNtcO/CVRETdTRPUHSFUnsY V5uPsK3x7lNdiqZYiPYzad4pqNHPJI/C1BPFqQyvG0nfjz1s+6e3va1z1TqY6dryifXb gnYg== X-Forwarded-Encrypted: i=1; AJvYcCUpDZKLxMv4ptEpZQ58sr1Alu8a6tT9lWfPt4C61F0kUAMiGPY3WCk6YAmeVwi7IXEdiffUR/f0cOJbew8=@vger.kernel.org X-Gm-Message-State: AOJu0YwoCZqYIRnCnJyfXy5R6IVV6UZF1xikzKfgLLS80asHGLxI19y/ J8Tx794AOjiS37EtDTgivjYkkmSiIytcYIl1fo1u8zWdzyiiXhuRLhJ4QJJhcG4Pk848ZNYIAu5 pxZcipvkquGBNdh3yWSS1J+oR9x49qV5sjhkQ7IKAPoqYNHPURhkVTeJeuzj7XvMrKKimmQP+IA == X-Gm-Gg: ASbGnctu7bb42wEZ74dbnz8Wi/07FtcPXQ2MrNvS1izhA3EV0IXk21VnqaehBEGZypu 8a/L0CS07cWwdD/pAfuatotQYPHCF416FEYf8bQCscipWgGsWUKqYKDQa9xtjY0P7/xV+nB3NLT LADAh9c5RNLvey64nJfxMtkuf0okcfbZSb5MdpZaO/RvL5ANUdNokdu2rW4qDhDkrez64u/PuBz Pa4illhtavA/CWodrok/RcE+m3JE6qF5hGKGcxc9U/Ac7mGI9VGc6dIv0cN/y6ob5ad+GzFhp6W dMa+xEn+UqIPX8bjJbJoT2+BEkNV X-Received: by 2002:a17:907:3f07:b0:b04:7ad5:b567 with SMTP id a640c23a62f3a-b07c35be704mr1472539766b.16.1757976355140; Mon, 15 Sep 2025 15:45:55 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFmaBx18ld1j9lPfAcqGZ9Y3KUZHbyO0pMr88z4kWYAY7x6NvXEEp1rRueqlASrcg16xLKuCQ== X-Received: by 2002:a17:907:3f07:b0:b04:7ad5:b567 with SMTP id a640c23a62f3a-b07c35be704mr1472538266b.16.1757976354746; Mon, 15 Sep 2025 15:45:54 -0700 (PDT) Received: from redhat.com ([31.187.78.47]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b0cf2112639sm440073566b.104.2025.09.15.15.45.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Sep 2025 15:45:54 -0700 (PDT) Date: Mon, 15 Sep 2025 18:45:51 -0400 From: "Michael S. Tsirkin" To: "Vishal Moola (Oracle)" Cc: David Hildenbrand , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: [PATCH v2 7/7] virtio_balloon: Stop calling page_address() in free_pages() Message-ID: <20250915184514-mutt-send-email-mst@kernel.org> References: <20250826205617.1032945-1-vishal.moola@gmail.com> <20250826205617.1032945-8-vishal.moola@gmail.com> <5ee2b684-94d9-40be-b01c-b0538ced33bc@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Aug 27, 2025 at 11:29:22AM -0700, Vishal Moola (Oracle) wrote: > On Wed, Aug 27, 2025 at 02:01:01PM +0200, David Hildenbrand wrote: > > On 26.08.25 22:56, Vishal Moola (Oracle) wrote: > > > free_pages() should be used when we only have a virtual address. We > > > should call __free_pages() directly on our page instead. > > > > > > Signed-off-by: Vishal Moola (Oracle) > > > --- > > > drivers/virtio/virtio_balloon.c | 3 +-- > > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > > > index eae65136cdfb..d4e6865ce355 100644 > > > --- a/drivers/virtio/virtio_balloon.c > > > +++ b/drivers/virtio/virtio_balloon.c > > > @@ -488,8 +488,7 @@ static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb, > > > page = balloon_page_pop(&vb->free_page_list); > > > if (!page) > > > break; > > > - free_pages((unsigned long)page_address(page), > > > - VIRTIO_BALLOON_HINT_BLOCK_ORDER); > > > + __free_pages(page, VIRTIO_BALLOON_HINT_BLOCK_ORDER); > > > } > > > vb->num_free_page_blocks -= num_returned; > > > spin_unlock_irq(&vb->free_page_list_lock); > > > > I think you missed another nastiness of similar kind in > > get_free_page_and_send() where we do > > > > p = page_address(page); > > > > Just to call > > > > free_pages((unsigned long)p, VIRTIO_BALLOON_HINT_BLOCK_ORDER); > > Thanks for catching that. Andrew can you fold the attached patch into > this one please? It looks like the page_address() call is needed for other > things, but since we're changing the file we might as well clean these > up as well. > > I imagine theres more of these lingering in the kernel, but theres so > many callers and I only looked for the ones that were calling > page_address() inline :(. Confused what is folded where. If you want me to apply these things please just fold whatever you want folded and post. Thanks! > >From a7d439154c7990418da976e5864b91fce9d49d58 Mon Sep 17 00:00:00 2001 > From: "Vishal Moola (Oracle)" > Date: Wed, 27 Aug 2025 11:10:22 -0700 > Subject: [PATCH] virtio_ballon: Call __free_pages() in > get_free_page_and_send() > > free_pages() should be used when we only have a virtual address. We > should call __free_pages() directly on our page instead. > > Signed-off-by: Vishal Moola (Oracle) > --- > drivers/virtio/virtio_balloon.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c > index d4e6865ce355..7f3fd72678eb 100644 > --- a/drivers/virtio/virtio_balloon.c > +++ b/drivers/virtio/virtio_balloon.c > @@ -718,8 +718,7 @@ static int get_free_page_and_send(struct virtio_balloon *vb) > if (vq->num_free > 1) { > err = virtqueue_add_inbuf(vq, &sg, 1, p, GFP_KERNEL); > if (unlikely(err)) { > - free_pages((unsigned long)p, > - VIRTIO_BALLOON_HINT_BLOCK_ORDER); > + __free_pages(page, VIRTIO_BALLOON_HINT_BLOCK_ORDER); > return err; > } > virtqueue_kick(vq); > @@ -732,7 +731,7 @@ static int get_free_page_and_send(struct virtio_balloon *vb) > * The vq has no available entry to add this page block, so > * just free it. > */ > - free_pages((unsigned long)p, VIRTIO_BALLOON_HINT_BLOCK_ORDER); > + __free_pages(page, VIRTIO_BALLOON_HINT_BLOCK_ORDER); > } > > return 0; > -- > 2.51.0 >