lwn.git/mm, branch docs-6.1

Merge tag 'mm-stable-2022-08-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-08-10T18:18:00+00:00

Pull remaining MM updates from Andrew Morton: "Three patch series - two that perform cleanups and one feature: - hugetlb_vmemmap cleanups from Muchun Song - hardware poisoning support for 1GB hugepages, from Naoya Horiguchi - highmem documentation fixups from Fabio De Francesco" * tag 'mm-stable-2022-08-09' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (23 commits) Documentation/mm: add details about kmap_local_page() and preemption highmem: delete a sentence from kmap_local_page() kdocs Documentation/mm: rrefer kmap_local_page() and avoid kmap() Documentation/mm: avoid invalid use of addresses from kmap_local_page() Documentation/mm: don't kmap*() pages which can't come from HIGHMEM highmem: specify that kmap_local_page() is callable from interrupts highmem: remove unneeded spaces in kmap_local_page() kdocs mm, hwpoison: enable memory error handling on 1GB hugepage mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage mm, hwpoison: make __page_handle_poison returns int mm, hwpoison: set PG_hwpoison for busy hugetlb pages mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage mm, hwpoison, hugetlb: support saving mechanism of raw error pages mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry mm/hugetlb: check gigantic_page_runtime_supported() in return_unused_surplus_pages() mm: hugetlb_vmemmap: use PTRS_PER_PTE instead of PMD_SIZE / PAGE_SIZE mm: hugetlb_vmemmap: move code comments to vmemmap_dedup.rst mm: hugetlb_vmemmap: improve hugetlb_vmemmap code readability mm: hugetlb_vmemmap: replace early_param() with core_param() mm: hugetlb_vmemmap: move vmemmap code related to HugeTLB to hugetlb_vmemmap.c ...

Merge tag 'cxl-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl

2022-08-10T18:07:26+00:00

Pull cxl updates from Dan Williams: "Compute Express Link (CXL) updates for 6.0: - Introduce a 'struct cxl_region' object with support for provisioning and assembling persistent memory regions. - Introduce alloc_free_mem_region() to accompany the existing request_free_mem_region() as a method to allocate physical memory capacity out of an existing resource. - Export insert_resource_expand_to_fit() for the CXL subsystem to late-publish CXL platform windows in iomem_resource. - Add a polled mode PCI DOE (Data Object Exchange) driver service and use it in cxl_pci to retrieve the CDAT (Coherent Device Attribute Table)" * tag 'cxl-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (74 commits) cxl/hdm: Fix skip allocations vs multiple pmem allocations cxl/region: Disallow region granularity != window granularity cxl/region: Fix x1 interleave to greater than x1 interleave routing cxl/region: Move HPA setup to cxl_region_attach() cxl/region: Fix decoder interleave programming Documentation: cxl: remove dangling kernel-doc reference cxl/region: describe targets and nr_targets members of cxl_region_params cxl/regions: add padding for cxl_rr_ep_add nested lists cxl/region: Fix IS_ERR() vs NULL check cxl/region: Fix region reference target accounting cxl/region: Fix region commit uninitialized variable warning cxl/region: Fix port setup uninitialized variable warnings cxl/region: Stop initializing interleave granularity cxl/hdm: Fix DPA reservation vs cxl_endpoint_decoder lifetime cxl/acpi: Minimize granularity for x1 interleaves cxl/region: Delete 'region' attribute from root decoders cxl/acpi: Autoload driver for 'cxl_acpi' test devices cxl/region: decrement ->nr_targets on error in cxl_region_attach() cxl/region: prevent underflow in ways_to_cxl() cxl/region: uninitialized variable in alloc_hpa() ...

Merge tag 'memblock-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2022-08-09T16:48:30+00:00

Pull memblock updates from Mike Rapoport: - An optimization in memblock_add_range() to reduce array traversals - Improvements to the memblock test suite * tag 'memblock-v5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock test: Modify the obsolete description in README memblock tests: fix compilation errors memblock tests: change build options to run-time options memblock tests: remove completed TODO items memblock tests: set memblock_debug to enable memblock_dbg() messages memblock tests: add verbose output to memblock tests memblock tests: Makefile: add arguments to control verbosity memblock: avoid some repeat when add new range

Merge tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2022-08-09T03:04:35+00:00

Pull more iov_iter updates from Al Viro: - more new_sync_{read,write}() speedups - ITER_UBUF introduction - ITER_PIPE cleanups - unification of iov_iter_get_pages/iov_iter_get_pages_alloc and switching them to advancing semantics - making ITER_PIPE take high-order pages without splitting them - handling copy_page_from_iter() for high-order pages properly * tag 'pull-work.iov_iter-rebased' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) fix copy_page_from_iter() for compound destinations hugetlbfs: copy_page_to_iter() can deal with compound pages copy_page_to_iter(): don't split high-order page in case of ITER_PIPE expand those iov_iter_advance()... pipe_get_pages(): switch to append_pipe() get rid of non-advancing variants ceph: switch the last caller of iov_iter_get_pages_alloc() 9p: convert to advancing variant of iov_iter_get_pages_alloc() af_alg_make_sg(): switch to advancing variant of iov_iter_get_pages() iter_to_pipe(): switch to advancing variant of iov_iter_get_pages() block: convert to advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: advancing variants of iov_iter_get_pages{,_alloc}() iov_iter: saner helper for page array allocation fold __pipe_get_pages() into pipe_get_pages() ITER_XARRAY: don't open-code DIV_ROUND_UP() unify the rest of iov_iter_get_pages()/iov_iter_get_pages_alloc() guts unify xarray_get_pages() and xarray_get_pages_alloc() unify pipe_get_pages() and pipe_get_pages_alloc() iov_iter_get_pages(): sanity-check arguments iov_iter_get_pages_alloc(): lift freeing pages array on failure exits into wrapper ...

new iov_iter flavour - ITER_UBUF

2022-08-09T02:37:15+00:00

Equivalent of single-segment iovec. Initialized by iov_iter_ubuf(), checked for by iter_is_ubuf(), otherwise behaves like ITER_IOVEC ones. We are going to expose the things like ->write_iter() et.al. to those in subsequent commits. New predicate (user_backed_iter()) that is true for ITER_IOVEC and ITER_UBUF; places like direct-IO handling should use that for checking that pages we modify after getting them from iov_iter_get_pages() would need to be dirtied. DO NOT assume that replacing iter_is_iovec() with user_backed_iter() will solve all problems - there's code that uses iter_is_iovec() to decide how to poke around in iov_iter guts and for that the predicate replacement obviously won't suffice. Signed-off-by: Al Viro

mm, hwpoison: enable memory error handling on 1GB hugepage

2022-08-09T01:06:44+00:00

Now error handling code is prepared, so remove the blocking code and enable memory error handling on 1GB hugepage. Link: https://lkml.kernel.org/r/20220714042420.1847125-9-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: kernel test robot Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton

mm, hwpoison: skip raw hwpoison page in freeing 1GB hugepage

2022-08-09T01:06:44+00:00

Currently if memory_failure() (modified to remove blocking code with subsequent patch) is called on a page in some 1GB hugepage, memory error handling fails and the raw error page gets into leaked state. The impact is small in production systems (just leaked single 4kB page), but this limits the testability because unpoison doesn't work for it. We can no longer create 1GB hugepage on the 1GB physical address range with such leaked pages, that's not useful when testing on small systems. When a hwpoison page in a 1GB hugepage is handled, it's caught by the PageHWPoison check in free_pages_prepare() because the 1GB hugepage is broken down into raw error pages before coming to this point: if (unlikely(PageHWPoison(page)) && !order) { ... return false; } Then, the page is not sent to buddy and the page refcount is left 0. Originally this check is supposed to work when the error page is freed from page_handle_poison() (that is called from soft-offline), but now we are opening another path to call it, so the callers of __page_handle_poison() need to handle the case by considering the return value 0 as success. Then page refcount for hwpoison is properly incremented so unpoison works. Link: https://lkml.kernel.org/r/20220714042420.1847125-8-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: kernel test robot Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton

mm, hwpoison: make __page_handle_poison returns int

2022-08-09T01:06:44+00:00

__page_handle_poison() returns bool that shows whether take_page_off_buddy() has passed or not now. But we will want to distinguish another case of "dissolve has passed but taking off failed" by its return value. So change the type of the return value. No functional change. Link: https://lkml.kernel.org/r/20220714042420.1847125-7-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: kernel test robot Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton

mm, hwpoison: set PG_hwpoison for busy hugetlb pages

2022-08-09T01:06:44+00:00

If memory_failure() fails to grab page refcount on a hugetlb page because it's busy, it returns without setting PG_hwpoison on it. This not only loses a chance of error containment, but breaks the rule that action_result() should be called only when memory_failure() do any of handling work (even if that's just setting PG_hwpoison). This inconsistency could harm code maintainability. So set PG_hwpoison and call hugetlb_set_page_hwpoison() for such a case. Link: https://lkml.kernel.org/r/20220714042420.1847125-6-naoya.horiguchi@linux.dev Fixes: 405ce051236c ("mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb()") Signed-off-by: Naoya Horiguchi Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: kernel test robot Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton

mm, hwpoison: make unpoison aware of raw error info in hwpoisoned hugepage

2022-08-09T01:06:44+00:00

Raw error info list needs to be removed when hwpoisoned hugetlb is unpoisoned. And unpoison handler needs to know how many errors there are in the target hugepage. So add them. HPageVmemmapOptimized(hpage) and HPageRawHwpUnreliable(hpage)) sometimes can't be unpoisoned, so skip them. Link: https://lkml.kernel.org/r/20220714042420.1847125-5-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi Reported-by: kernel test robot Reviewed-by: Miaohe Lin Cc: David Hildenbrand Cc: Liu Shixin Cc: Mike Kravetz Cc: Muchun Song Cc: Oscar Salvador Cc: Yang Shi Signed-off-by: Andrew Morton