Messages in this thread | | | From | Guomin Chen <> | Subject | RE: [PATCH 1/1] resource: Fixed iomem resource release failed on release_mem_region_adjustable() when memory node or cpu node hot-remove. | Date | Wed, 27 Jun 2018 06:43:36 +0000 |
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Hi Toshi Thank you for your reply and suggestions. I will continue to follow and investigation this issue. thanks
Thanks and regards
> -----Original Message----- > From: Kani, Toshi [mailto:toshi.kani@hpe.com] > Sent: 2018年6月26日 7:56 > To: Guomin Chen <guomin.chen@suse.com>; helgaas@kernel.org > Cc: linux-kernel@vger.kernel.org; Joey Lee <JLee@suse.com>; bp@suse.de; > tglx@linutronix.de; tiwai@suse.de; akpm@linux-foundation.org; > dan.j.williams@intel.com; linux-efi@vger.kernel.org; bhelgaas@google.com; > thomas.lendacky@amd.com; brijesh.singh@amd.com; > baiyaowei@cmss.chinamobile.com > Subject: Re: [PATCH 1/1] resource: Fixed iomem resource release failed on > release_mem_region_adjustable() when memory node or cpu node > hot-remove. > > On Fri, 2018-06-22 at 18:19 -0500, Bjorn Helgaas wrote: > > [+cc Toshi] > > > > On Fri, Jun 22, 2018 at 08:01:38PM +0800, guomin chen wrote: > > > We've got a bug report indicating the hot-remove node resource > > > release failed,when the memory on this node is divided into several > > > sections.because the release_mem_region_adjustable() can only > > > release one resource that must be [start,end]. > > > > Can you please include a URL for the bug report? That's useful for > > additional details and gives hints about how future changes in this > > area might be tested. > > > > release_mem_region_adjustable() and the only call to it were added by > > Toshi (cc'd): > > > > 825f787bb496 ("resource: add release_mem_region_adjustable()") > > fe74ebb106a5 ("mm: change __remove_pages() to call > > release_mem_region_adjustable()") > > > > > In my case, the BIOS supports faulty memory isolation. if BIOS > > > detected bad memory block, the BIOS will isolates this badblock. > > > And set this badblock memory to EfiUnusableMemory in EFI memory map > > > base on UEFI 2.7 spec.For example in my system, the memory range on > > > node2 is [mem 0x0000080000000000-0x00000807ffffffff].but the BIOS > > > detected the [8004e000000-8004e0fffff] is a badblock memory. > > > So the memory on node2 seem like this: > > > 80000000000-8004dffffff : System RAM > > > 8004e000000-8004e0fffff : Unusable memory > > > 8004e100000-807ffffffff : System RAM > > > > > > Now, when offline the cpu node2,the kernel will try to release > > > ioresource [mem 0x0000080000000000-0x00000807ffffffff]. at this > > > time, the kernel will release failed,and output error message: > > > "Unable to release resource <0x0000080000000000-0x00000807ffffffff> > > > (-22)". > > Hmm... this BIO implementation does not sound right to me. When EFI > memory map has a hole, ACPI memory object should have the same hole in its > resource info. If so, this node2 memory hot-delete would have requested a > deletion of 2 separate System RAM ranges, not a single range including this > hole. This is also important for memory hot-add. ACPI memory object needs > to describe this hole in order for the OS to avoid adding this badblock memory. > > Thanks, > -Toshi
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