- 19 Oct, 2020 3 commits
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git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds authored
Pull more xfs updates from Darrick Wong: "The second large pile of new stuff for 5.10, with changes even more monumental than last week! We are formally announcing the deprecation of the V4 filesystem format in 2030. All users must upgrade to the V5 format, which contains design improvements that greatly strengthen metadata validation, supports reflink and online fsck, and is the intended vehicle for handling timestamps past 2038. We're also deprecating the old Irix behavioral tweaks in September 2025. Coming along for the ride are two design changes to the deferred metadata ops subsystem. One of the improvements is to retain correct logical ordering of tasks and subtasks, which is a more logical design for upper layers of XFS and will become necessary when we add atomic file range swaps and commits. The second improvement to deferred ops improves the scalability of the log by helping the log tail to move forward during long-running operations. This reduces log contention when there are a large number of threads trying to run transactions. In addition to that, this fixes numerous small bugs in log recovery; refactors logical intent log item recovery to remove the last remaining place in XFS where we could have nested transactions; fixes a couple of ways that intent log item recovery could fail in ways that wouldn't have happened in the regular commit paths; fixes a deadlock vector in the GETFSMAP implementation (which improves its performance by 20%); and fixes serious bugs in the realtime growfs, fallocate, and bitmap handling code. Summary: - Deprecate the V4 filesystem format, some disused mount options, and some legacy sysctl knobs now that we can support dates into the 25th century. Note that removal of V4 support will not happen until the early 2030s. - Fix some probles with inode realtime flag propagation. - Fix some buffer handling issues when growing a rt filesystem. - Fix a problem where a BMAP_REMAP unmap call would free rt extents even though the purpose of BMAP_REMAP is to avoid freeing the blocks. - Strengthen the dabtree online scrubber to check hash values on child dabtree blocks. - Actually log new intent items created as part of recovering log intent items. - Fix a bug where quotas weren't attached to an inode undergoing bmap intent item recovery. - Fix a buffer overrun problem with specially crafted log buffer headers. - Various cleanups to type usage and slightly inaccurate comments. - More cleanups to the xattr, log, and quota code. - Don't run the (slower) shared-rmap operations on attr fork mappings. - Fix a bug where we failed to check the LSN of finobt blocks during replay and could therefore overwrite newer data with older data. - Clean up the ugly nested transaction mess that log recovery uses to stage intent item recovery in the correct order by creating a proper data structure to capture recovered chains. - Use the capture structure to resume intent item chains with the same log space and block reservations as when they were captured. - Fix a UAF bug in bmap intent item recovery where we failed to maintain our reference to the incore inode if the bmap operation needed to relog itself to continue. - Rearrange the defer ops mechanism to finish newly created subtasks of a parent task before moving on to the next parent task. - Automatically relog intent items in deferred ops chains if doing so would help us avoid pinning the log tail. This will help fix some log scaling problems now and will facilitate atomic file updates later. - Fix a deadlock in the GETFSMAP implementation by using an internal memory buffer to reduce indirect calls and copies to userspace, thereby improving its performance by ~20%. - Fix various problems when calling growfs on a realtime volume would not fully update the filesystem metadata. - Fix broken Kconfig asking about deprecated XFS when XFS is disabled" * tag 'xfs-5.10-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (48 commits) xfs: fix Kconfig asking about XFS_SUPPORT_V4 when XFS_FS=n xfs: fix high key handling in the rt allocator's query_range function xfs: annotate grabbing the realtime bitmap/summary locks in growfs xfs: make xfs_growfs_rt update secondary superblocks xfs: fix realtime bitmap/summary file truncation when growing rt volume xfs: fix the indent in xfs_trans_mod_dquot xfs: do the ASSERT for the arguments O_{u,g,p}dqpp xfs: fix deadlock and streamline xfs_getfsmap performance xfs: limit entries returned when counting fsmap records xfs: only relog deferred intent items if free space in the log gets low xfs: expose the log push threshold xfs: periodically relog deferred intent items xfs: change the order in which child and parent defer ops are finished xfs: fix an incore inode UAF in xfs_bui_recover xfs: clean up xfs_bui_item_recover iget/trans_alloc/ilock ordering xfs: clean up bmap intent item recovery checking xfs: xfs_defer_capture should absorb remaining transaction reservation xfs: xfs_defer_capture should absorb remaining block reservations xfs: proper replay of deferred ops queued during log recovery xfs: remove XFS_LI_RECOVERED ... -
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds authored
Pull fuse updates from Miklos Szeredi: - Support directly accessing host page cache from virtiofs. This can improve I/O performance for various workloads, as well as reducing the memory requirement by eliminating double caching. Thanks to Vivek Goyal for doing most of the work on this. - Allow automatic submounting inside virtiofs. This allows unique st_dev/ st_ino values to be assigned inside the guest to files residing on different filesystems on the host. Thanks to Max Reitz for the patches. - Fix an old use after free bug found by Pradeep P V K. * tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits) virtiofs: calculate number of scatter-gather elements accurately fuse: connection remove fix fuse: implement crossmounts fuse: Allow fuse_fill_super_common() for submounts fuse: split fuse_mount off of fuse_conn fuse: drop fuse_conn parameter where possible fuse: store fuse_conn in fuse_req fuse: add submount support to <uapi/linux/fuse.h> fuse: fix page dereference after free virtiofs: add logic to free up a memory range virtiofs: maintain a list of busy elements virtiofs: serialize truncate/punch_hole and dax fault path virtiofs: define dax address space operations virtiofs: add DAX mmap support virtiofs: implement dax read/write operations virtiofs: introduce setupmapping/removemapping commands virtiofs: implement FUSE_INIT map_alignment field virtiofs: keep a list of free dax memory ranges virtiofs: add a mount option to enable dax virtiofs: set up virtio_fs dax_device ...
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git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefsLinus Torvalds authored
Pull zonefs updates from Damien Le Moal: "Add an 'explicit-open' mount option to automatically issue a REQ_OP_ZONE_OPEN command to the device whenever a sequential zone file is open for writing for the first time. This avoids 'insufficient zone resources' errors for write operations on some drives with limited zone resources or on ZNS drives with a limited number of active zones. From Johannes" * tag 'zonefs-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs: zonefs: document the explicit-open mount option zonefs: open/close zone on file open/close zonefs: provide no-lock zonefs_io_error variant zonefs: introduce helper for zone management
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- 18 Oct, 2020 37 commits
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Linus Torvalds authored
Merge tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull more Kunit updates from Shuah Khan: - add Kunit to kernel_init() and remove KUnit from init calls entirely. This addresses the concern that Kunit would not work correctly during late init phase. - add a linker section where KUnit can put references to its test suites. This is the first step in transitioning to dispatching all KUnit tests from a centralized executor rather than having each as its own separate late_initcall. - add a centralized executor to dispatch tests rather than relying on late_initcall to schedule each test suite separately. Centralized execution is for built-in tests only; modules will execute tests when loaded. - convert bitfield test to use KUnit framework - Documentation updates for naming guidelines and how kunit_test_suite() works. - add test plan to KUnit TAP format * tag 'linux-kselftest-kunit-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: lib: kunit: Fix compilation test when using TEST_BIT_FIELD_COMPILE lib: kunit: add bitfield test conversion to KUnit Documentation: kunit: add a brief blurb about kunit_test_suite kunit: test: add test plan to KUnit TAP format init: main: add KUnit to kernel init kunit: test: create a single centralized executor for all tests vmlinux.lds.h: add linker section for KUnit test suites Documentation: kunit: Add naming guidelines
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull RCU changes from Ingo Molnar: - Debugging for smp_call_function() - RT raw/non-raw lock ordering fixes - Strict grace periods for KASAN - New smp_call_function() torture test - Torture-test updates - Documentation updates - Miscellaneous fixes [ This doesn't actually pull the tag - I've dropped the last merge from the RCU branch due to questions about the series. - Linus ] * tag 'core-rcu-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (77 commits) smp: Make symbol 'csd_bug_count' static kernel/smp: Provide CSD lock timeout diagnostics smp: Add source and destination CPUs to __call_single_data rcu: Shrink each possible cpu krcp rcu/segcblist: Prevent useless GP start if no CBs to accelerate torture: Add gdb support rcutorture: Allow pointer leaks to test diagnostic code rcutorture: Hoist OOM registry up one level refperf: Avoid null pointer dereference when buf fails to allocate rcutorture: Properly synchronize with OOM notifier rcutorture: Properly set rcu_fwds for OOM handling torture: Add kvm.sh --help and update help message rcutorture: Add CONFIG_PROVE_RCU_LIST to TREE05 torture: Update initrd documentation rcutorture: Replace HTTP links with HTTPS ones locktorture: Make function torture_percpu_rwsem_init() static torture: document --allcpus argument added to the kvm.sh script rcutorture: Output number of elapsed grace periods rcutorture: Remove KCSAN stubs rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp() ...
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git://git.linaro.org/landing-teams/working/fujitsu/integrationLinus Torvalds authored
Pull mailbox updates from Jassi Brar: - arm: implementation of mhu as a doorbell driver and conversion of dt-bindings to json-schema - mediatek: fix platform_get_irq error handling - bcm: convert tasklets to use new tasklet_setup api - core: fix race cause by hrtimer starting inappropriately * tag 'mailbox-v5.10' of git://git.linaro.org/landing-teams/working/fujitsu/integration: mailbox: avoid timer start from callback maiblox: mediatek: Fix handling of platform_get_irq() error mailbox: arm_mhu: Add ARM MHU doorbell driver mailbox: arm_mhu: Match only if compatible is "arm,mhu" dt-bindings: mailbox: add doorbell support to ARM MHU dt-bindings: mailbox : arm,mhu: Convert to Json-schema mailbox: bcm: convert tasklets to use new tasklet_setup() API
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git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linuxLinus Torvalds authored
Pull coccinelle updates from Julia Lawall. * 'for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jlawall/linux: coccinelle: api: add kfree_mismatch script coccinelle: iterators: Add for_each_child.cocci script scripts: coccicheck: Change default condition for parallelism scripts: coccicheck: Add quotes to improve portability coccinelle: api: kfree_sensitive: print memset position coccinelle: misc: add flexible_array.cocci script coccinelle: api: add kvmalloc script scripts: coccicheck: Change default value for parallelism coccinelle: misc: add excluded_middle.cocci script scripts: coccicheck: Improve error feedback when coccicheck fails coccinelle: api: update kzfree script to kfree_sensitive coccinelle: misc: add uninitialized_var.cocci script coccinelle: ifnullfree: add vfree(), kvfree*() functions coccinelle: api: add kobj_to_dev.cocci script coccinelle: add patch rule for dma_alloc_coherent scripts: coccicheck: Add chain mode to list of modes
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Linus Torvalds authored
Merge yet more updates from Andrew Morton: "Subsystems affected by this patch series: mm (memcg, migration, pagemap, gup, madvise, vmalloc), ia64, and misc" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits) mm: remove duplicate include statement in mmu.c mm: remove the filename in the top of file comment in vmalloc.c mm: cleanup the gfp_mask handling in __vmalloc_area_node mm: remove alloc_vm_area x86/xen: open code alloc_vm_area in arch_gnttab_valloc xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv drm/i915: use vmap in i915_gem_object_map drm/i915: stop using kmap in i915_gem_object_map drm/i915: use vmap in shmem_pin_map zsmalloc: switch from alloc_vm_area to get_vm_area mm: allow a NULL fn callback in apply_to_page_range mm: add a vmap_pfn function mm: add a VM_MAP_PUT_PAGES flag for vmap mm: update the documentation for vfree mm/madvise: introduce process_madvise() syscall: an external memory hinting API pid: move pidfd_get_pid() to pid.c mm/madvise: pass mm to do_madvise selftests/vm: 10x speedup for hmm-tests binfmt_elf: take the mmap lock around find_extend_vma() mm/gup_benchmark: take the mmap lock around GUP ...
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/umlLinus Torvalds authored
Pull UML updates from Richard Weinberger: - Improve support for non-glibc systems - Vector: Add support for scripting and dynamic tap devices - Various fixes for the vector networking driver - Various fixes for time travel mode * tag 'for-linus-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml: um: vector: Add dynamic tap interfaces and scripting um: Clean up stacktrace dump um: Fix incorrect assumptions about max pid length um: Remove dead usage of TIF_IA32 um: Remove redundant NULL check um: change sigio_spinlock to a mutex um: time-travel: Return the sequence number in ACK messages um: time-travel: Fix IRQ handling in time_travel_handle_message() um: Allow static linking for non-glibc implementations um: Some fixes to build UML with musl um: vector: Use GFP_ATOMIC under spin lock um: Fix null pointer dereference in vector_user_bpf
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifsLinus Torvalds authored
Pull more ubi and ubifs updates from Richard Weinberger: "UBI: - Correctly use kthread_should_stop in ubi worker UBIFS: - Fixes for memory leaks while iterating directory entries - Fix for a user triggerable error message - Fix for a space accounting bug in authenticated mode" * tag 'for-linus-5.10-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: ubifs: journal: Make sure to not dirty twice for auth nodes ubifs: setflags: Don't show error message when vfs_ioc_setflags_prepare() fails ubifs: ubifs_jnl_change_xattr: Remove assertion 'nlink > 0' for host inode ubi: check kthread_should_stop() after the setting of task state ubifs: dent: Fix some potential memory leaks while iterating entries ubifs: xattr: Fix some potential memory leaks while iterating entries
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git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifsLinus Torvalds authored
Pull ubifs updates from Richard Weinberger: - Kernel-doc fixes - Fixes for memory leaks in authentication option parsing * tag 'for-linus-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs: ubifs: mount_ubifs: Release authentication resource in error handling path ubifs: Don't parse authentication mount options in remount process ubifs: Fix a memleak after dumping authentication mount options ubifs: Fix some kernel-doc warnings in tnc.c ubifs: Fix some kernel-doc warnings in replay.c ubifs: Fix some kernel-doc warnings in gc.c ubifs: Fix 'hash' kernel-doc warning in auth.c
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Tian Tao authored
asm/sections.h is included more than once, Remove the one that isn't necessary. Signed-off-by:
Tian Tao <tiantao6@hisilicon.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Reviewed-by:
Mike Rapoport <rppt@linux.ibm.com> Link: https://lkml.kernel.org/r/1600088607-17327-1-git-send-email-tiantao6@hisilicon.comSigned-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Christoph Hellwig authored
No point in having the filename inside the file. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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Christoph Hellwig authored
Patch series "two small vmalloc cleanups". This patch (of 2): __vmalloc_area_node currently has four different gfp_t variables to just express this simple logic: - use the passed in mask, plus __GFP_NOWARN and __GFP_HIGHMEM (if suitable) for the underlying page allocation - use just the reclaim flags from the passed in mask plus __GFP_ZERO for allocating the page array Simplify this down to just use the pre-existing nested_gfp as-is for the page array allocation, and just the passed in gfp_mask for the page allocation, after conditionally ORing __GFP_HIGHMEM into it. This also makes the allocation warning a little more correct. Also initialize two variables at the time of declaration while touching this area. Signed-off-by:
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Christoph Hellwig authored
All users are gone now. Signed-off-by:
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Christoph Hellwig authored
Replace the last call to alloc_vm_area with an open coded version using an iterator in struct gnttab_vm_area instead of the triple indirection magic in alloc_vm_area. Signed-off-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Juergen Gross <jgross@suse.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Link: https://lkml.kernel.org/r/20201002122204.1534411-11-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Replacing alloc_vm_area with get_vm_area_caller + apply_page_range allows to fill put the phys_addr values directly instead of doing another loop over all addresses. Signed-off-by:
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Christoph Hellwig authored
i915_gem_object_map implements fairly low-level vmap functionality in a driver. Split it into two helpers, one for remapping kernel memory which can use vmap, and one for I/O memory that uses vmap_pfn. The only practical difference is that alloc_vm_area prefeaults the vmalloc area PTEs, which doesn't seem to be required here for the kernel memory case (and could be added to vmap using a flag if actually required). Signed-off-by:
Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Juergen Gross <jgross@suse.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Link: https://lkml.kernel.org/r/20201002122204.1534411-9-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
kmap for !PageHighmem is just a convoluted way to say page_address, and kunmap is a no-op in that case. Signed-off-by:
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Christoph Hellwig authored
shmem_pin_map somewhat awkwardly reimplements vmap using alloc_vm_area and manual pte setup. The only practical difference is that alloc_vm_area prefeaults the vmalloc area PTEs, which doesn't seem to be required here (and could be added to vmap using a flag if actually required). Switch to use vmap, and use vfree to free both the vmalloc mapping and the page array, as well as dropping the references to each page. Signed-off-by:
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Christoph Hellwig authored
Just manually pre-fault the PTEs using apply_to_page_range. Co-developed-by:
Minchan Kim <minchan@kernel.org> Signed-off-by:
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Christoph Hellwig authored
Besides calling the callback on each page, apply_to_page_range also has the effect of pre-faulting all PTEs for the range. To support callers that only need the pre-faulting, make the callback optional. Based on a patch from Minchan Kim <minchan@kernel.org>. Signed-off-by:
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Christoph Hellwig authored
Add a proper helper to remap PFNs into kernel virtual space so that drivers don't have to abuse alloc_vm_area and open coded PTE manipulation for it. Signed-off-by:
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Christoph Hellwig authored
Add a flag so that vmap takes ownership of the passed in page array. When vfree is called on such an allocation it will put one reference on each page, and free the page array itself. Signed-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "remove alloc_vm_area", v4. This series removes alloc_vm_area, which was left over from the big vmalloc interface rework. It is a rather arkane interface, basicaly the equivalent of get_vm_area + actually faulting in all PTEs in the allocated area. It was originally addeds for Xen (which isn't modular to start with), and then grew users in zsmalloc and i915 which seems to mostly qualify as abuses of the interface, especially for i915 as a random driver should not set up PTE bits directly. This patch (of 11): * Document that you can call vfree() on an address returned from vmap() * Remove the note about the minimum size -- the minimum size of a vmalloc allocation is one page * Add a Context: section * Fix capitalisation * Reword the prohibition on calling from NMI context to avoid a double negative Signed-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:
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Minchan Kim authored
There is usecase that System Management Software(SMS) want to give a memory hint like MADV_[COLD|PAGEEOUT] to other processes and in the case of Android, it is the ActivityManagerService. The information required to make the reclaim decision is not known to the app. Instead, it is known to the centralized userspace daemon(ActivityManagerService), and that daemon must be able to initiate reclaim on its own without any app involvement. To solve the issue, this patch introduces a new syscall process_madvise(2). It uses pidfd of an external process to give the hint. It also supports vector address range because Android app has thousands of vmas due to zygote so it's totally waste of CPU and power if we should call the syscall one by one for each vma.(With testing 2000-vma syscall vs 1-vector syscall, it showed 15% performance improvement. I think it would be bigger in real practice because the testing ran very cache friendly environment). Another potential use case for the vector range is to amortize the cost ofTLB shootdowns for multiple ranges when using MADV_DONTNEED; this could benefit users like TCP receive zerocopy and malloc implementations. In future, we could find more usecases for other advises so let's make it happens as API since we introduce a new syscall at this moment. With that, existing madvise(2) user could replace it with process_madvise(2) with their own pid if they want to have batch address ranges support feature. ince it could affect other process's address range, only privileged process(PTRACE_MODE_ATTACH_FSCREDS) or something else(e.g., being the same UID) gives it the right to ptrace the process could use it successfully. The flag argument is reserved for future use if we need to extend the API. I think supporting all hints madvise has/will supported/support to process_madvise is rather risky. Because we are not sure all hints make sense from external process and implementation for the hint may rely on the caller being in the current context so it could be error-prone. Thus, I just limited hints as MADV_[COLD|PAGEOUT] in this patch. If someone want to add other hints, we could hear the usecase and review it for each hint. It's safer for maintenance rather than introducing a buggy syscall but hard to fix it later. So finally, the API is as follows, ssize_t process_madvise(int pidfd, const struct iovec *iovec, unsigned long vlen, int advice, unsigned int flags); DESCRIPTION The process_madvise() system call is used to give advice or directions to the kernel about the address ranges from external process as well as local process. It provides the advice to address ranges of process described by iovec and vlen. The goal of such advice is to improve system or application performance. The pidfd selects the process referred to by the PID file descriptor specified in pidfd. (See pidofd_open(2) for further information) The pointer iovec points to an array of iovec structures, defined in <sys/uio.h> as: struct iovec { void *iov_base; /* starting address */ size_t iov_len; /* number of bytes to be advised */ }; The iovec describes address ranges beginning at address(iov_base) and with size length of bytes(iov_len). The vlen represents the number of elements in iovec. The advice is indicated in the advice argument, which is one of the following at this moment if the target process specified by pidfd is external. MADV_COLD MADV_PAGEOUT Permission to provide a hint to external process is governed by a ptrace access mode PTRACE_MODE_ATTACH_FSCREDS check; see ptrace(2). The process_madvise supports every advice madvise(2) has if target process is in same thread group with calling process so user could use process_madvise(2) to extend existing madvise(2) to support vector address ranges. RETURN VALUE On success, process_madvise() returns the number of bytes advised. This return value may be less than the total number of requested bytes, if an error occurred. The caller should check return value to determine whether a partial advice occurred. FAQ: Q.1 - Why does any external entity have better knowledge? Quote from Sandeep "For Android, every application (including the special SystemServer) are forked from Zygote. The reason of course is to share as many libraries and classes between the two as possible to benefit from the preloading during boot. After applications start, (almost) all of the APIs end up calling into this SystemServer process over IPC (binder) and back to the application. In a fully running system, the SystemServer monitors every single process periodically to calculate their PSS / RSS and also decides which process is "important" to the user for interactivity. So, because of how these processes start _and_ the fact that the SystemServer is looping to monitor each process, it does tend to *know* which address range of the application is not used / useful. Besides, we can never rely on applications to clean things up themselves. We've had the "hey app1, the system is low on memory, please trim your memory usage down" notifications for a long time[1]. They rely on applications honoring the broadcasts and very few do. So, if we want to avoid the inevitable killing of the application and restarting it, some way to be able to tell the OS about unimportant memory in these applications will be useful. - ssp Q.2 - How to guarantee the race(i.e., object validation) between when giving a hint from an external process and get the hint from the target process? process_madvise operates on the target process's address space as it exists at the instant that process_madvise is called. If the space target process can run between the time the process_madvise process inspects the target process address space and the time that process_madvise is actually called, process_madvise may operate on memory regions that the calling process does not expect. It's the responsibility of the process calling process_madvise to close this race condition. For example, the calling process can suspend the target process with ptrace, SIGSTOP, or the freezer cgroup so that it doesn't have an opportunity to change its own address space before process_madvise is called. Another option is to operate on memory regions that the caller knows a priori will be unchanged in the target process. Yet another option is to accept the race for certain process_madvise calls after reasoning that mistargeting will do no harm. The suggested API itself does not provide synchronization. It also apply other APIs like move_pages, process_vm_write. The race isn't really a problem though. Why is it so wrong to require that callers do their own synchronization in some manner? Nobody objects to write(2) merely because it's possible for two processes to open the same file and clobber each other's writes --- instead, we tell people to use flock or something. Think about mmap. It never guarantees newly allocated address space is still valid when the user tries to access it because other threads could unmap the memory right before. That's where we need synchronization by using other API or design from userside. It shouldn't be part of API itself. If someone needs more fine-grained synchronization rather than process level, there were two ideas suggested - cookie[2] and anon-fd[3]. Both are applicable via using last reserved argument of the API but I don't think it's necessary right now since we have already ways to prevent the race so don't want to add additional complexity with more fine-grained optimization model. To make the API extend, it reserved an unsigned long as last argument so we could support it in future if someone really needs it. Q.3 - Why doesn't ptrace work? Injecting an madvise in the target process using ptrace would not work for us because such injected madvise would have to be executed by the target process, which means that process would have to be runnable and that creates the risk of the abovementioned race and hinting a wrong VMA. Furthermore, we want to act the hint in caller's context, not the callee's, because the callee is usually limited in cpuset/cgroups or even freezed state so they can't act by themselves quick enough, which causes more thrashing/kill. It doesn't work if the target process are ptraced(e.g., strace, debugger, minidump) because a process can have at most one ptracer. [1] https://developer.android.com/topic/performance/memory" [2] process_getinfo for getting the cookie which is updated whenever vma of process address layout are changed - Daniel Colascione - https://lore.kernel.org/lkml/20190520035254.57579-1-minchan@kernel.org/T/#m7694416fd179b2066a2c62b5b139b14e3894e224 [3] anonymous fd which is used for the object(i.e., address range) validation - Michal Hocko - https://lore.kernel.org/lkml/20200120112722.GY18451@dhcp22.suse.cz/ [minchan@kernel.org: fix process_madvise build break for arm64] Link: http://lkml.kernel.org/r/20200303145756.GA219683@google.com [minchan@kernel.org: fix build error for mips of process_madvise] Link: http://lkml.kernel.org/r/20200508052517.GA197378@google.com [akpm@linux-foundation.org: fix patch ordering issue] [akpm@linux-foundation.org: fix arm64 whoops] [minchan@kernel.org: make process_madvise() vlen arg have type size_t, per Florian] [akpm@linux-foundation.org: fix i386 build] [sfr@canb.auug.org.au: fix syscall numbering] Link: https://lkml.kernel.org/r/20200905142639.49fc3f1a@canb.auug.org.au [sfr@canb.auug.org.au: madvise.c needs compat.h] Link: https://lkml.kernel.org/r/20200908204547.285646b4@canb.auug.org.au [minchan@kernel.org: fix mips build] Link: https://lkml.kernel.org/r/20200909173655.GC2435453@google.com [yuehaibing@huawei.com: remove duplicate header which is included twice] Link: https://lkml.kernel.org/r/20200915121550.30584-1-yuehaibing@huawei.com [minchan@kernel.org: do not use helper functions for process_madvise] Link: https://lkml.kernel.org/r/20200921175539.GB387368@google.com [akpm@linux-foundation.org: pidfd_get_pid() gained an argument] [sfr@canb.auug.org.au: fix up for "iov_iter: transparently handle compat iovecs in import_iovec"] Link: https://lkml.kernel.org/r/20200928212542.468e1fef@canb.auug.org.auSigned-off-by:YueHaibing <yuehaibing@huawei.com> Signed-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
Suren Baghdasaryan <surenb@google.com> Reviewed-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
David Rientjes <rientjes@google.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <christian@brauner.io> Cc: Daniel Colascione <dancol@google.com> Cc: Jann Horn <jannh@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Dias <joaodias@google.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksandr Natalenko <oleksandr@redhat.com> Cc: Sandeep Patil <sspatil@google.com> Cc: SeongJae Park <sj38.park@gmail.com> Cc: SeongJae Park <sjpark@amazon.de> Cc: Shakeel Butt <shakeelb@google.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: <linux-man@vger.kernel.org> Link: http://lkml.kernel.org/r/20200302193630.68771-3-minchan@kernel.org Link: http://lkml.kernel.org/r/20200508183320.GA125527@google.com Link: http://lkml.kernel.org/r/20200622192900.22757-4-minchan@kernel.org Link: https://lkml.kernel.org/r/20200901000633.1920247-4-minchan@kernel.orgSigned-off-by:
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Minchan Kim authored
process_madvise syscall needs pidfd_get_pid function to translate pidfd to pid so this patch move the function to kernel/pid.c. Suggested-by:
Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by:
Christian Brauner <christian.brauner@ubuntu.com> Acked-by:
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Minchan Kim authored
Patch series "introduce memory hinting API for external process", v9. Now, we have MADV_PAGEOUT and MADV_COLD as madvise hinting API. With that, application could give hints to kernel what memory range are preferred to be reclaimed. However, in some platform(e.g., Android), the information required to make the hinting decision is not known to the app. Instead, it is known to a centralized userspace daemon(e.g., ActivityManagerService), and that daemon must be able to initiate reclaim on its own without any app involvement. To solve the concern, this patch introduces new syscall - process_madvise(2). Bascially, it's same with madvise(2) syscall but it has some differences. 1. It needs pidfd of target process to provide the hint 2. It supports only MADV_{COLD|PAGEOUT|MERGEABLE|UNMEREABLE} at this moment. Other hints in madvise will be opened when there are explicit requests from community to prevent unexpected bugs we couldn't support. 3. Only privileged processes can do something for other process's address space. For more detail of the new API, please see "mm: introduce external memory hinting API" description in this patchset. This patch (of 3): In upcoming patches, do_madvise will be called from external process context so we shouldn't asssume "current" is always hinted process's task_struct. Furthermore, we must not access mm_struct via task->mm, but obtain it via access_mm() once (in the following patch) and only use that pointer [1], so pass it to do_madvise() as well. Note the vma->vm_mm pointers are safe, so we can use them further down the call stack. And let's pass current->mm as arguments of do_madvise so it shouldn't change existing behavior but prepare next patch to make review easy. [vbabka@suse.cz: changelog tweak] [minchan@kernel.org: use current->mm for io_uring] Link: http://lkml.kernel.org/r/20200423145215.72666-1-minchan@kernel.org [akpm@linux-foundation.org: fix it for upstream changes] [akpm@linux-foundation.org: whoops] [rdunlap@infradead.org: add missing includes] Signed-off-by: -
John Hubbard authored
This patch reduces the running time for hmm-tests from about 10+ seconds, to just under 1.0 second, for an approximately 10x speedup. That brings it in line with most of the other tests in selftests/vm, which mostly run in < 1 sec. This is done with a one-line change that simply reduces the number of iterations of several tests, from 256, to 10. Thanks to Ralph Campbell for suggesting changing NTIMES as a way to get the speedup. Suggested-by:
Ralph Campbell <rcampbell@nvidia.com> Signed-off-by:
John Hubbard <jhubbard@nvidia.com> Signed-off-by:
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Jann Horn authored
create_elf_tables() runs after setup_new_exec(), so other tasks can already access our new mm and do things like process_madvise() on it. (At the time I'm writing this commit, process_madvise() is not in mainline yet, but has been in akpm's tree for some time.) While I believe that there are currently no APIs that would actually allow another process to mess up our VMA tree (process_madvise() is limited to MADV_COLD and MADV_PAGEOUT, and uring and userfaultfd cannot reach an mm under which no syscalls have been executed yet), this seems like an accident waiting to happen. Let's make sure that we always take the mmap lock around GUP paths as long as another process might be able to see the mm. (Yes, this diff looks suspicious because we drop the lock before doing anything with `vma`, but that's because we actually don't do anything with it apart from the NULL check.) Signed-off-by:
Jann Horn <jannh@google.com> Signed-off-by:
Michel Lespinasse <walken@google.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Link: https://lkml.kernel.org/r/CAG48ez1-PBCdv3y8pn-Ty-b+FmBSLwDuVKFSt8h7wARLy0dF-Q@mail.gmail.comSigned-off-by:
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Jann Horn authored
To be safe against concurrent changes to the VMA tree, we must take the mmap lock around GUP operations (excluding the GUP-fast family of operations, which will take the mmap lock by themselves if necessary). This code is only for testing, and it's only reachable by root through debugfs, so this doesn't really have any impact; however, if we want to add lockdep asserts into the GUP path, we need to have clean locking here. Signed-off-by:
Jason Gunthorpe <jgg@nvidia.com> Reviewed-by:
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Liam R. Howlett authored
There are two locations that have a block of code for munmapping a vma range. Change those two locations to use a function and add meaningful comments about what happens to the arguments, which was unclear in the previous code. Signed-off-by:
Liam R. Howlett <Liam.Howlett@Oracle.com> Signed-off-by:
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Liam R. Howlett authored
There are three places that the next vma is required which uses the same block of code. Replace the block with a function and add comments on what happens in the case where NULL is encountered. Signed-off-by:
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Miaohe Lin authored
There is no need to check if this process has the right to modify the specified process when they are same. And we could also skip the security hook call if a process is modifying its own pages. Add helper function to handle these. Suggested-by:
Hongxiang Lou <louhongxiang@huawei.com> Signed-off-by:
Miaohe Lin <linmiaohe@huawei.com> Signed-off-by:
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Joonsoo Kim authored
To calculate the correct node to migrate the page for hotplug, we need to check node id of the page. Wrapper for alloc_migration_target() exists for this purpose. However, Vlastimil informs that all migration source pages come from a single node. In this case, we don't need to check the node id for each page and we don't need to re-set the target nodemask for each page by using the wrapper. Set up the migration_target_control once and use it for all pages. Signed-off-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
Michal Hocko <mhocko@suse.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Roman Gushchin <guro@fb.com> Link: http://lkml.kernel.org/r/1594622517-20681-10-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by:
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Joonsoo Kim authored
There is a well-defined standard migration target callback. Use it directly. Signed-off-by:
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Roman Gushchin authored
If a memcg to charge can be determined (using remote charging API), there are no reasons to exclude allocations made from an interrupt context from the accounting. Such allocations will pass even if the resulting memcg size will exceed the hard limit, but it will affect the application of the memory pressure and an inability to put the workload under the limit will eventually trigger the OOM. To use active_memcg() helper, memcg_kmem_bypass() is moved back to memcontrol.c. Signed-off-by:
Roman Gushchin <guro@fb.com> Signed-off-by:
Shakeel Butt <shakeelb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Link: http://lkml.kernel.org/r/20200827225843.1270629-5-guro@fb.comSigned-off-by:
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Roman Gushchin authored
Remote memcg charging API uses current->active_memcg to store the currently active memory cgroup, which overwrites the memory cgroup of the current process. It works well for normal contexts, but doesn't work for interrupt contexts: indeed, if an interrupt occurs during the execution of a section with an active memcg set, all allocations inside the interrupt will be charged to the active memcg set (given that we'll enable accounting for allocations from an interrupt context). But because the interrupt might have no relation to the active memcg set outside, it's obviously wrong from the accounting prospective. To resolve this problem, let's add a global percpu int_active_memcg variable, which will be used to store an active memory cgroup which will be used from interrupt contexts. set_active_memcg() will transparently use current->active_memcg or int_active_memcg depending on the context. To make the read part simple and transparent for the caller, let's introduce two new functions: - struct mem_cgroup *active_memcg(void), - struct mem_cgroup *get_active_memcg(void). They are returning the active memcg if it's set, hiding all implementation details: where to get it depending on the current context. Signed-off-by:
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Roman Gushchin authored
There are checks for current->mm and current->active_memcg in get_obj_cgroup_from_current(), but these checks are redundant: memcg_kmem_bypass() called just above performs same checks. Signed-off-by:
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Roman Gushchin authored
Patch series "mm: kmem: kernel memory accounting in an interrupt context". This patchset implements memcg-based memory accounting of allocations made from an interrupt context. Historically, such allocations were passed unaccounted mostly because charging the memory cgroup of the current process wasn't an option. Also performance reasons were likely a reason too. The remote charging API allows to temporarily overwrite the currently active memory cgroup, so that all memory allocations are accounted towards some specified memory cgroup instead of the memory cgroup of the current process. This patchset extends the remote charging API so that it can be used from an interrupt context. Then it removes the fence that prevented the accounting of allocations made from an interrupt context. It also contains a couple of optimizations/code refactorings. This patchset doesn't directly enable accounting for any specific allocations, but prepares the code base for it. The bpf memory accounting will likely be the first user of it: a typical example is a bpf program parsing an incoming network packet, which allocates an entry in hashmap map to store some information. This patch (of 4): Currently memcg_kmem_bypass() is called before obtaining the current memory/obj cgroup using get_mem/obj_cgroup_from_current(). Moving memcg_kmem_bypass() into get_mem/obj_cgroup_from_current() reduces the number of call sites and allows further code simplifications. Signed-off-by:
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