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Wed, 21 Aug 2019 04:30:32 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 191A78AC6FF; Wed, 21 Aug 2019 08:30:32 +0000 (UTC) Received: from [10.36.118.29] (unknown [10.36.118.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 464EF5D6B7; Wed, 21 Aug 2019 08:30:30 +0000 (UTC) Subject: Re: [PATCH] vmw_balloon: Fix offline page marking with compaction To: Nadav Amit , Greg Kroah-Hartman Cc: Arnd Bergmann , "VMware, Inc." , linux-kernel@vger.kernel.org, Thomas Hellstrom References: <20190820160121.452-1-namit@vmware.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: <291b8bcd-df68-3f5e-2985-fcaa46c1ff38@redhat.com> Date: Wed, 21 Aug 2019 10:30:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190820160121.452-1-namit@vmware.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.69]); Wed, 21 Aug 2019 08:30:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20.08.19 18:01, Nadav Amit wrote: > The compaction code already marks pages as offline when it enqueues > pages in the ballooned page list, and removes the mapping when the pages > are removed from the list. VMware balloon also updates the flags, > instead of letting the balloon-compaction logic handle it, which causes > the assertion VM_BUG_ON_PAGE(!PageOffline(page)) to fire, when > __ClearPageOffline is called the second time. This causes the following > crash. > > [ 487.104520] kernel BUG at include/linux/page-flags.h:749! > [ 487.106364] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI > [ 487.107681] CPU: 7 PID: 1106 Comm: kworker/7:3 Not tainted 5.3.0-rc5balloon #227 > [ 487.109196] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018 > [ 487.111452] Workqueue: events_freezable vmballoon_work [vmw_balloon] > [ 487.112779] RIP: 0010:vmballoon_release_page_list+0xaa/0x100 [vmw_balloon] > [ 487.114200] Code: fe 48 c1 e7 06 4c 01 c7 8b 47 30 41 89 c1 41 81 e1 00 01 00 f0 41 81 f9 00 00 00 f0 74 d3 48 c7 c6 08 a1 a1 c0 e8 06 0d e7 ea <0f> 0b 44 89 f6 4c 89 c7 e8 49 9c e9 ea 49 8d 75 08 49 8b 45 08 4d > [ 487.118033] RSP: 0018:ffffb82f012bbc98 EFLAGS: 00010246 > [ 487.119135] RAX: 0000000000000037 RBX: 0000000000000001 RCX: 0000000000000006 > [ 487.120601] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9a85b6bd7620 > [ 487.122071] RBP: ffffb82f012bbcc0 R08: 0000000000000001 R09: 0000000000000000 > [ 487.123536] R10: 0000000000000000 R11: 0000000000000000 R12: ffffb82f012bbd00 > [ 487.125002] R13: ffffe97f4598d9c0 R14: 0000000000000000 R15: ffffb82f012bbd34 > [ 487.126463] FS: 0000000000000000(0000) GS:ffff9a85b6bc0000(0000) knlGS:0000000000000000 > [ 487.128110] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 487.129316] CR2: 00007ffe6e413ea0 CR3: 0000000230b18001 CR4: 00000000003606e0 > [ 487.130812] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 487.132283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [ 487.133749] Call Trace: > [ 487.134333] vmballoon_deflate+0x22c/0x390 [vmw_balloon] > [ 487.135468] vmballoon_work+0x6e7/0x913 [vmw_balloon] > [ 487.136711] ? process_one_work+0x21a/0x5e0 > [ 487.138581] process_one_work+0x298/0x5e0 > [ 487.139926] ? vmballoon_migratepage+0x310/0x310 [vmw_balloon] > [ 487.141610] ? process_one_work+0x298/0x5e0 > [ 487.143053] worker_thread+0x41/0x400 > [ 487.144389] kthread+0x12b/0x150 > [ 487.145582] ? process_one_work+0x5e0/0x5e0 > [ 487.146937] ? kthread_create_on_node+0x60/0x60 > [ 487.148637] ret_from_fork+0x3a/0x50 > > Fix it by updating the PageOffline indication only when a 2MB page is > enqueued and dequeued. The 4KB pages will be handled correctly by the > balloon compaction logic. > > Fixes: 83a8afa72e9c ("vmw_balloon: Compaction support") > Cc: David Hildenbrand > Reported-by: Thomas Hellstrom > Signed-off-by: Nadav Amit > --- > drivers/misc/vmw_balloon.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c > index 8840299420e0..5e6be1527571 100644 > --- a/drivers/misc/vmw_balloon.c > +++ b/drivers/misc/vmw_balloon.c > @@ -691,7 +691,6 @@ static int vmballoon_alloc_page_list(struct vmballoon *b, > } > > if (page) { > - vmballoon_mark_page_offline(page, ctl->page_size); > /* Success. Add the page to the list and continue. */ > list_add(&page->lru, &ctl->pages); > continue; > @@ -930,7 +929,6 @@ static void vmballoon_release_page_list(struct list_head *page_list, > > list_for_each_entry_safe(page, tmp, page_list, lru) { > list_del(&page->lru); > - vmballoon_mark_page_online(page, page_size); > __free_pages(page, vmballoon_page_order(page_size)); > } > > @@ -1005,6 +1003,7 @@ static void vmballoon_enqueue_page_list(struct vmballoon *b, > enum vmballoon_page_size_type page_size) > { > unsigned long flags; > + struct page *page; > > if (page_size == VMW_BALLOON_4K_PAGE) { > balloon_page_list_enqueue(&b->b_dev_info, pages); > @@ -1014,6 +1013,11 @@ static void vmballoon_enqueue_page_list(struct vmballoon *b, > * for the balloon compaction mechanism. > */ > spin_lock_irqsave(&b->b_dev_info.pages_lock, flags); > + > + list_for_each_entry(page, pages, lru) { > + vmballoon_mark_page_offline(page, VMW_BALLOON_2M_PAGE); > + } > + > list_splice_init(pages, &b->huge_pages); > __count_vm_events(BALLOON_INFLATE, *n_pages * > vmballoon_page_in_frames(VMW_BALLOON_2M_PAGE)); > @@ -1056,6 +1060,8 @@ static void vmballoon_dequeue_page_list(struct vmballoon *b, > /* 2MB pages */ > spin_lock_irqsave(&b->b_dev_info.pages_lock, flags); > list_for_each_entry_safe(page, tmp, &b->huge_pages, lru) { > + vmballoon_mark_page_online(page, VMW_BALLOON_2M_PAGE); > + > list_move(&page->lru, pages); > if (++i == n_req_pages) > break; > Or check in vmballoon_mark_page_online/vmballoon_mark_page_offline if already properly marked, adding a comment. But what you have should also work. -- Thanks, David / dhildenb