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Commit24b6d41643"mm: pass the vmem_altmap to vmemmap_free" converted the vmemmap_free() path to pass the altmap argument all the way through the call chain rather than looking it up based on the page. Unfortunately that ends up over freeing altmap allocated pages in some cases since free_pagetable() is used to free both memmap space and pte space, where only the memmap stored in huge pages uses altmap allocations. Given that altmap allocations for memmap space are special cased in vmemmap_populate_hugepages() add a symmetric / special case free_hugepage_table() to handle altmap freeing, and cleanup the unneeded passing of altmap to leaf functions that do not require it. Without this change the sanity check accounting in devm_memremap_pages_release() will throw a warning with the following signature. nd_pmem pfn10.1: devm_memremap_pages_release: failed to free all reserved pages WARNING: CPU: 44 PID: 3539 at kernel/memremap.c:310 devm_memremap_pages_release+0x1c7/0x220 CPU: 44 PID: 3539 Comm: ndctl Tainted: G L 4.16.0-rc1-linux-stable #7 RIP: 0010:devm_memremap_pages_release+0x1c7/0x220 [..] Call Trace: release_nodes+0x225/0x270 device_release_driver_internal+0x15d/0x210 bus_remove_device+0xe2/0x160 device_del+0x130/0x310 ? klist_release+0x56/0x100 ? nd_region_notify+0xc0/0xc0 [libnvdimm] device_unregister+0x16/0x60 This was missed in testing since not all configurations will trigger this warning. Fixes:24b6d41643("mm: pass the vmem_altmap to vmemmap_free") Reported-by: Jane Chu <jane.chu@oracle.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.