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2020-04-02Merge branch 'pci/enumeration'Bjorn Helgaas
- Add PCIe 32 GT/s speed decoding for sysfs "max_link_speed" and dmesg notes about available bandwidth (Yicong Yang) - Simplify and unify PCI bus/link speed reporting (Yicong Yang) * pci/enumeration: PCI: Add PCIE_LNKCAP2_SLS2SPEED() macro PCI: Use pci_speed_string() for all PCI/PCI-X/PCIe strings PCI: Add pci_speed_string() PCI: Add 32 GT/s decoding in some macros
2020-04-02Merge branch 'pci/edr'Bjorn Helgaas
- Update error status after reset_link() so we don't report "recovery failed" when it in fact succeeded (Kuppuswamy Sathyanarayanan) - Move DPC data into struct pci_dev instead of allocating a separate struct dpc_dev (Bjorn Helgaas) - Remove AER/DPC service dependency to simplify error recovery (Kuppuswamy Sathyanarayanan) - Return error recovery status for future use by EDR, which needs to tell firmware whether recovery was successful (Kuppuswamy Sathyanarayanan) - Cache DPC capability info in core since it's needed by EDR as well as DPC driver (Kuppuswamy Sathyanarayanan) - Add pci_aer_raw_clear_status() to allow EDR recovery path to clear AER status even when OS doesn't own the AER capability (Kuppuswamy Sathyanarayanan) - Add Error Disconnect Recover (EDR) support, so firmware can use ACPI notification to tell the OS that devices have been disconnected, e.g., via DPC, and that OS should attempt recovery (Kuppuswamy Sathyanarayanan) - Rename AER error status clearing interfaces to be more consistent (Kuppuswamy Sathyanarayanan) * pci/edr: PCI/AER: Rationalize error status register clearing PCI/DPC: Add Error Disconnect Recover (EDR) support PCI/DPC: Expose dpc_process_error(), dpc_reset_link() for use by EDR PCI/AER: Add pci_aer_raw_clear_status() to unconditionally clear Error Status PCI/DPC: Cache DPC capabilities in pci_init_capabilities() PCI/ERR: Return status of pcie_do_recovery() PCI/ERR: Remove service dependency in pcie_do_recovery() PCI/DPC: Move DPC data into struct pci_dev PCI/ERR: Update error status after reset_link() PCI/ERR: Combine pci_channel_io_frozen cases
2020-04-02Merge branch 'pci/aspm'Bjorn Helgaas
- Clear the correct bits when enabling ASPM L1 substates (Yicong Yang) - Reduce severity of ASPM common clock config message (Chris Packham) * pci/aspm: PCI/ASPM: Reduce severity of common clock config message PCI/ASPM: Clear the correct bits when enabling L1 substates
2020-04-02x86/kvm: fix a missing-prototypes "vmread_error"Qian Cai
The commit 842f4be95899 ("KVM: VMX: Add a trampoline to fix VMREAD error handling") removed the declaration of vmread_error() causes a W=1 build failure with KVM_WERROR=y. Fix it by adding it back. arch/x86/kvm/vmx/vmx.c:359:17: error: no previous prototype for 'vmread_error' [-Werror=missing-prototypes] asmlinkage void vmread_error(unsigned long field, bool fault) ^~~~~~~~~~~~ Signed-off-by: Qian Cai <cai@lca.pw> Message-Id: <20200402153955.1695-1-cai@lca.pw> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-04-02Merge branches 'misc' and 'devel-stable' into for-linusRussell King
2020-04-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull exec/proc updates from Eric Biederman: "This contains two significant pieces of work: the work to sort out proc_flush_task, and the work to solve a deadlock between strace and exec. Fixing proc_flush_task so that it no longer requires a persistent mount makes improvements to proc possible. The removal of the persistent mount solves an old regression that that caused the hidepid mount option to only work on remount not on mount. The regression was found and reported by the Android folks. This further allows Alexey Gladkov's work making proc mount options specific to an individual mount of proc to move forward. The work on exec starts solving a long standing issue with exec that it takes mutexes of blocking userspace applications, which makes exec extremely deadlock prone. For the moment this adds a second mutex with a narrower scope that handles all of the easy cases. Which makes the tricky cases easy to spot. With a little luck the code to solve those deadlocks will be ready by next merge window" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (25 commits) signal: Extend exec_id to 64bits pidfd: Use new infrastructure to fix deadlocks in execve perf: Use new infrastructure to fix deadlocks in execve proc: io_accounting: Use new infrastructure to fix deadlocks in execve proc: Use new infrastructure to fix deadlocks in execve kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve kernel: doc: remove outdated comment cred.c mm: docs: Fix a comment in process_vm_rw_core selftests/ptrace: add test cases for dead-locks exec: Fix a deadlock in strace exec: Add exec_update_mutex to replace cred_guard_mutex exec: Move exec_mmap right after de_thread in flush_old_exec exec: Move cleanup of posix timers on exec out of de_thread exec: Factor unshare_sighand out of de_thread and call it separately exec: Only compute current once in flush_old_exec pid: Improve the comment about waiting in zap_pid_ns_processes proc: Remove the now unnecessary internal mount of proc uml: Create a private mount of proc for mconsole uml: Don't consult current to find the proc_mnt in mconsole_proc proc: Use a list of inodes to flush from proc ...
2020-04-02misc: pci_endpoint_test: remove duplicate macro PCI_ENDPOINT_TEST_STATUSLad Prabhakar
PCI_ENDPOINT_TEST_STATUS is already defined in pci_endpoint_test.c along with the status bits, drop the duplicate definition. Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02PCI: tegra: Print -EPROBE_DEFER error message at debug levelThierry Reding
Probe deferral is an expected error condition that will usually be recovered from. Print such error messages at debug level to make them available for diagnostic purposes when building with debugging enabled and hide them otherwise to not spam the kernel log with them. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reviewed-by: Vidya Sagar <vidyas@nvidia.com> Tested-by: Vidya Sagar <vidyas@nvidia.com>
2020-04-02misc: pci_endpoint_test: Use full pci-endpoint-test name in request_irq()Kishon Vijay Abraham I
Use full pci-endpoint-test name in request_irq(), so that it's easy to profile the device that actually raised the interrupt. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02misc: pci_endpoint_test: Fix to support > 10 pci-endpoint-test devicesKishon Vijay Abraham I
Adding more than 10 pci-endpoint-test devices results in "kobject_add_internal failed for pci-endpoint-test.1 with -EEXIST, don't try to register things with the same name in the same directory". This is because commit 2c156ac71c6b ("misc: Add host side PCI driver for PCI test function device") limited the length of the "name" to 20 characters. Change the length of the name to 24 in order to support upto 10000 pci-endpoint-test devices. Fixes: 2c156ac71c6b ("misc: Add host side PCI driver for PCI test function device") Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org # v4.14+
2020-04-02tools: PCI: Add 'e' to clear IRQKishon Vijay Abraham I
Add a new command line option 'e' to invoke "PCITEST_CLEAR_IRQ" ioctl. This can be used to clear the irqs set using the 'i' option. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02misc: pci_endpoint_test: Add ioctl to clear IRQKishon Vijay Abraham I
Add ioctl to clear IRQ which can be used to free the allocated IRQ vectors and free the requested IRQ. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02misc: pci_endpoint_test: Avoid using module parameter to determine irqtypeKishon Vijay Abraham I
commit e03327122e2c ("pci_endpoint_test: Add 2 ioctl commands") uses module parameter 'irqtype' in pci_endpoint_test_set_irq() to check if IRQ vectors of a particular type (MSI or MSI-X or LEGACY) is already allocated. However with multi-function devices, 'irqtype' will not correctly reflect the IRQ type of the PCI device. Fix it here by adding 'irqtype' for each PCI device to show the IRQ type of a particular PCI device. Fixes: e03327122e2c ("pci_endpoint_test: Add 2 ioctl commands") Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: stable@vger.kernel.org # v4.19+
2020-04-02PCI: keystone: Allow AM654 PCIe Endpoint to raise MSI-X interruptKishon Vijay Abraham I
AM654 PCIe EP controller has MSI-X capability register and has the ability to raise MSI-X interrupt. Add support in pci-keystone.c for PCIe endpoint controller in AM654 to raise MSI-X interrupts. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02PCI: dwc: Fix dw_pcie_ep_raise_msix_irq() to get correct MSI-X table addressKishon Vijay Abraham I
commit beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler"), in order to raise MSI-X interrupt, obtained MSIX table address from Base Address Register (BAR). However BAR only holds PCI address programmed by the host whereas the MSI-X table should be in the local memory. Store the MSI-X table address (virtual address) as part of ->set_bar() callback and use that to get the message address and message data here. Fixes: beb4641a787d ("PCI: dwc: Add MSI-X callbacks handler") Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02PCI: endpoint: Fix ->set_msix() to take BIR and offset as argumentsKishon Vijay Abraham I
commit 8963106eabdc ("PCI: endpoint: Add MSI-X interfaces") while adding support to raise MSI-X interrupts from endpoint didn't include BAR Indicator register (BIR) configuration and MSI-X table offset as arguments in pci_epc_set_msix(). This would result in endpoint controller register using random BAR indicator register, the memory for which might not be allocated by the endpoint function driver. Add BAR indicator register and MSI-X table offset as arguments in pci_epc_set_msix() and allocate space for MSI-X table and pending bit array (PBA) in pci-epf-test endpoint function driver. Fixes: 8963106eabdc ("PCI: endpoint: Add MSI-X interfaces") Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2020-04-02misc: pci_endpoint_test: Add support to get DMA option from userspaceKishon Vijay Abraham I
'pcitest' utility now uses '-d' option to allow the user to test DMA. Add support to parse option to use DMA from userspace application. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Alan Mikhak <alan.mikhak@sifive.com>
2020-04-02tools: PCI: Add 'd' command line option to support DMAKishon Vijay Abraham I
Add a new command line option 'd' to use DMA for data transfers. It should be used with read, write or copy commands. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Alan Mikhak <alan.mikhak@sifive.com>
2020-04-02misc: pci_endpoint_test: Use streaming DMA APIs for buffer allocationKishon Vijay Abraham I
Use streaming DMA APIs (dma_map_single/dma_unmap_single) for buffers transmitted/received by the endpoint device instead of allocating a coherent memory. Also add default_data to set the alignment to 4KB since dma_map_single might not return a 4KB aligned address. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Alan Mikhak <alan.mikhak@sifive.com>
2020-04-02PCI: endpoint: functions/pci-epf-test: Print throughput informationKishon Vijay Abraham I
Print throughput information in KB/s after every completed transfer, including information on whether DMA is used or not. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Alan Mikhak <alan.mikhak@sifive.com>
2020-04-02PCI: endpoint: functions/pci-epf-test: Add DMA support to transfer dataKishon Vijay Abraham I
Use dmaengine API and add support for transferring data using DMA. Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Alan Mikhak <alan.mikhak@sifive.com>
2020-04-02include/linux/huge_mm.h: check PageTail in hpage_nr_pages even when !THPMatthew Wilcox (Oracle)
It's even more important to check that we don't have a tail page when calling hpage_nr_pages() when THP are disabled. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Link: http://lkml.kernel.org/r/20200318140253.6141-4-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/hugetlb: fix build failure with HUGETLB_PAGE but not HUGEBTLBFSChristophe Leroy
When CONFIG_HUGETLB_PAGE is set but not CONFIG_HUGETLBFS, the following build failure is encoutered: In file included from arch/powerpc/mm/fault.c:33:0: include/linux/hugetlb.h: In function 'hstate_inode': include/linux/hugetlb.h:477:9: error: implicit declaration of function 'HUGETLBFS_SB' [-Werror=implicit-function-declaration] return HUGETLBFS_SB(i->i_sb)->hstate; ^ include/linux/hugetlb.h:477:30: error: invalid type argument of '->' (have 'int') return HUGETLBFS_SB(i->i_sb)->hstate; ^ Gate hstate_inode() with CONFIG_HUGETLBFS instead of CONFIG_HUGETLB_PAGE. Fixes: a137e1cc6d6e ("hugetlbfs: per mount huge page sizes") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Baoquan He <bhe@redhat.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Adam Litke <agl@us.ibm.com> Cc: Andi Kleen <ak@suse.de> Link: http://lkml.kernel.org/r/7e8c3a3c9a587b9cd8a2f146df32a421b961f3a2.1584432148.git.christophe.leroy@c-s.fr Link: https://patchwork.ozlabs.org/patch/1255548/#2386036 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02selftests/vm: fix map_hugetlb length used for testing read and writeChristophe Leroy
Commit fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") added the possibility to change the size of memory mapped for the test, but left the read and write test using the default value. This is unnoticed when mapping a length greater than the default one, but segfaults otherwise. Fix read_bytes() and write_bytes() by giving them the real length. Also fix the call to munmap(). Fixes: fa7b9a805c79 ("tools/selftest/vm: allow choosing mem size and page size in map_hugetlb") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Shuah Khan <shuah@kernel.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/9a404a13c871c4bd0ba9ede68f69a1225180dd7e.1580978385.git.christophe.leroy@c-s.fr Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/hugetlb: remove unnecessary memory fetch in PageHeadHuge()Vlastimil Babka
Commit f1e61557f023 ("mm: pack compound_dtor and compound_order into one word in struct page") changed compound_dtor from a pointer to an array index in order to pack it. To check if page has the hugeltbfs compound_dtor, we can just compare the index directly without fetching the function pointer. Said commit did that with PageHuge() and we can do the same with PageHeadHuge() to make the code a bit smaller and faster. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Neha Agarwal <nehaagarwal@google.com> Link: http://lkml.kernel.org/r/20200311172440.6988-1-vbabka@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/hugetlb.c: clean code by removing unnecessary initializationMateusz Nosek
Previously variable 'check_addr' was initialized, but was not read later before reassigning. So the initialization can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Link: http://lkml.kernel.org/r/20200303212354.25226-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add hugetlb_cgroup reservation docsMina Almasry
Add docs for how to use hugetlb_cgroup reservations, and their behavior. Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-9-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add hugetlb_cgroup reservation testsMina Almasry
The tests use both shared and private mapped hugetlb memory, and monitors the hugetlb usage counter as well as the hugetlb reservation counter. They test different configurations such as hugetlb memory usage via hugetlbfs, or MAP_HUGETLB, or shmget/shmat, and with and without MAP_POPULATE. Also add test for hugetlb reservation reparenting, since this is a subtle issue. Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Sandipan Das <sandipan@linux.ibm.com> [powerpc64] Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-8-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb: support file_region coalescing againMina Almasry
An earlier patch in this series disabled file_region coalescing in order to hang the hugetlb_cgroup uncharge info on the file_region entries. This patch re-adds support for coalescing of file_region entries. Essentially everytime we add an entry, we call a recursive function that tries to coalesce the added region with the regions next to it. The worst case call depth for this function is 3: one to coalesce with the region next to it, one to coalesce to the region prev, and one to reach the base case. This is an important performance optimization as private mappings add their entries page by page, and we could incur big performance costs for large mappings with lots of file_region entries in their resv_map. [almasrymina@google.com: fix CONFIG_CGROUP_HUGETLB ifdefs] Link: http://lkml.kernel.org/r/20200214204544.231482-1-almasrymina@google.com [almasrymina@google.com: remove check_coalesce_bug debug code] Link: http://lkml.kernel.org/r/20200219233610.13808-1-almasrymina@google.com Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Link: http://lkml.kernel.org/r/20200211213128.73302-7-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: support noreserve mappingsMina Almasry
Support MAP_NORESERVE accounting as part of the new counter. For each hugepage allocation, at allocation time we check if there is a reservation for this allocation or not. If there is a reservation for this allocation, then this allocation was charged at reservation time, and we don't re-account it. If there is no reserevation for this allocation, we charge the appropriate hugetlb_cgroup. The hugetlb_cgroup to uncharge for this allocation is stored in page[3].private. We use new APIs added in an earlier patch to set this pointer. Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-6-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add accounting for shared mappingsMina Almasry
For shared mappings, the pointer to the hugetlb_cgroup to uncharge lives in the resv_map entries, in file_region->reservation_counter. After a call to region_chg, we charge the approprate hugetlb_cgroup, and if successful, we pass on the hugetlb_cgroup info to a follow up region_add call. When a file_region entry is added to the resv_map via region_add, we put the pointer to that cgroup in file_region->reservation_counter. If charging doesn't succeed, we report the error to the caller, so that the kernel fails the reservation. On region_del, which is when the hugetlb memory is unreserved, we also uncharge the file_region->reservation_counter. [akpm@linux-foundation.org: forward declare struct file_region] Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-5-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb: disable region_add file_region coalescingMina Almasry
A follow up patch in this series adds hugetlb cgroup uncharge info the file_region entries in resv->regions. The cgroup uncharge info may differ for different regions, so they can no longer be coalesced at region_add time. So, disable region coalescing in region_add in this patch. Behavior change: Say a resv_map exists like this [0->1], [2->3], and [5->6]. Then a region_chg/add call comes in region_chg/add(f=0, t=5). Old code would generate resv->regions: [0->5], [5->6]. New code would generate resv->regions: [0->1], [1->2], [2->3], [3->5], [5->6]. Special care needs to be taken to handle the resv->adds_in_progress variable correctly. In the past, only 1 region would be added for every region_chg and region_add call. But now, each call may add multiple regions, so we can no longer increment adds_in_progress by 1 in region_chg, or decrement adds_in_progress by 1 after region_add or region_abort. Instead, region_chg calls add_reservation_in_range() to count the number of regions needed and allocates those, and that info is passed to region_add and region_abort to decrement adds_in_progress correctly. We've also modified the assumption that region_add after region_chg never fails. region_chg now pre-allocates at least 1 region for region_add. If region_add needs more regions than region_chg has allocated for it, then it may fail. [almasrymina@google.com: fix file_region entry allocations] Link: http://lkml.kernel.org/r/20200219012736.20363-1-almasrymina@google.com Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Link: http://lkml.kernel.org/r/20200211213128.73302-4-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add reservation accounting for private mappingsMina Almasry
Normally the pointer to the cgroup to uncharge hangs off the struct page, and gets queried when it's time to free the page. With hugetlb_cgroup reservations, this is not possible. Because it's possible for a page to be reserved by one task and actually faulted in by another task. The best place to put the hugetlb_cgroup pointer to uncharge for reservations is in the resv_map. But, because the resv_map has different semantics for private and shared mappings, the code patch to charge/uncharge shared and private mappings is different. This patch implements charging and uncharging for private mappings. For private mappings, the counter to uncharge is in resv_map->reservation_counter. On initializing the resv_map this is set to NULL. On reservation of a region in private mapping, the tasks hugetlb_cgroup is charged and the hugetlb_cgroup is placed is resv_map->reservation_counter. On hugetlb_vm_op_close, we uncharge resv_map->reservation_counter. [akpm@linux-foundation.org: forward declare struct resv_map] Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-3-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/hugetlb_cgroup: fix hugetlb_cgroup migrationMina Almasry
Commit c32300516047 ("hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations") mistakingly doesn't handle the migration of *both* the reservation hugetlb_cgroup and the fault hugetlb_cgroup correctly. What should happen is that both cgroups shuold be queried from the old page, then both set to NULL on the old page, then both inserted into the new page. The mistake also creates the following warning: mm/hugetlb_cgroup.c: In function 'hugetlb_cgroup_migrate': mm/hugetlb_cgroup.c:777:25: warning: variable 'h_cg' set but not used [-Wunused-but-set-variable] struct hugetlb_cgroup *h_cg; ^~~~ Solution is to add the missing steps, namly setting the reservation hugetlb_cgroup to NULL on the old page, and setting the fault hugetlb_cgroup on the new page. Fixes: c32300516047 ("hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations") Reported-by: Qian Cai <cai@lca.pw> Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200218194727.46995-1-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add interface for charge/uncharge hugetlb reservationsMina Almasry
Augments hugetlb_cgroup_charge_cgroup to be able to charge hugetlb usage or hugetlb reservation counter. Adds a new interface to uncharge a hugetlb_cgroup counter via hugetlb_cgroup_uncharge_counter. Integrates the counter with hugetlb_cgroup, via hugetlb_cgroup_init, hugetlb_cgroup_have_usage, and hugetlb_cgroup_css_offline. Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/20200211213128.73302-2-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlb_cgroup: add hugetlb_cgroup reservation counterMina Almasry
These counters will track hugetlb reservations rather than hugetlb memory faulted in. This patch only adds the counter, following patches add the charging and uncharging of the counter. This is patch 1 of an 9 patch series. Problem: Currently tasks attempting to reserve more hugetlb memory than is available get a failure at mmap/shmget time. This is thanks to Hugetlbfs Reservations [1]. However, if a task attempts to reserve more hugetlb memory than its hugetlb_cgroup limit allows, the kernel will allow the mmap/shmget call, but will SIGBUS the task when it attempts to fault in the excess memory. We have users hitting their hugetlb_cgroup limits and thus we've been looking at this failure mode. We'd like to improve this behavior such that users violating the hugetlb_cgroup limits get an error on mmap/shmget time, rather than getting SIGBUS'd when they try to fault the excess memory in. This gives the user an opportunity to fallback more gracefully to non-hugetlbfs memory for example. The underlying problem is that today's hugetlb_cgroup accounting happens at hugetlb memory *fault* time, rather than at *reservation* time. Thus, enforcing the hugetlb_cgroup limit only happens at fault time, and the offending task gets SIGBUS'd. Proposed Solution: A new page counter named 'hugetlb.xMB.rsvd.[limit|usage|max_usage]_in_bytes'. This counter has slightly different semantics than 'hugetlb.xMB.[limit|usage|max_usage]_in_bytes': - While usage_in_bytes tracks all *faulted* hugetlb memory, rsvd.usage_in_bytes tracks all *reserved* hugetlb memory and hugetlb memory faulted in without a prior reservation. - If a task attempts to reserve more memory than limit_in_bytes allows, the kernel will allow it to do so. But if a task attempts to reserve more memory than rsvd.limit_in_bytes, the kernel will fail this reservation. This proposal is implemented in this patch series, with tests to verify functionality and show the usage. Alternatives considered: 1. A new cgroup, instead of only a new page_counter attached to the existing hugetlb_cgroup. Adding a new cgroup seemed like a lot of code duplication with hugetlb_cgroup. Keeping hugetlb related page counters under hugetlb_cgroup seemed cleaner as well. 2. Instead of adding a new counter, we considered adding a sysctl that modifies the behavior of hugetlb.xMB.[limit|usage]_in_bytes, to do accounting at reservation time rather than fault time. Adding a new page_counter seems better as userspace could, if it wants, choose to enforce different cgroups differently: one via limit_in_bytes, and another via rsvd.limit_in_bytes. This could be very useful if you're transitioning how hugetlb memory is partitioned on your system one cgroup at a time, for example. Also, someone may find usage for both limit_in_bytes and rsvd.limit_in_bytes concurrently, and this approach gives them the option to do so. Testing: - Added tests passing. - Used libhugetlbfs for regression testing. [1]: https://www.kernel.org/doc/html/latest/vm/hugetlbfs_reserv.html Signed-off-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Sandipan Das <sandipan@linux.ibm.com> Link: http://lkml.kernel.org/r/20200211213128.73302-1-almasrymina@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlbfs: Use i_mmap_rwsem to address page fault/truncate raceMike Kravetz
hugetlbfs page faults can race with truncate and hole punch operations. Current code in the page fault path attempts to handle this by 'backing out' operations if we encounter the race. One obvious omission in the current code is removing a page newly added to the page cache. This is pretty straight forward to address, but there is a more subtle and difficult issue of backing out hugetlb reservations. To handle this correctly, the 'reservation state' before page allocation needs to be noted so that it can be properly backed out. There are four distinct possibilities for reservation state: shared/reserved, shared/no-resv, private/reserved and private/no-resv. Backing out a reservation may require memory allocation which could fail so that needs to be taken into account as well. Instead of writing the required complicated code for this rare occurrence, just eliminate the race. i_mmap_rwsem is now held in read mode for the duration of page fault processing. Hold i_mmap_rwsem in write mode when modifying i_size. In this way, truncation can not proceed when page faults are being processed. In addition, i_size will not change during fault processing so a single check can be made to ensure faults are not beyond (proposed) end of file. Faults can still race with hole punch, but that race is handled by existing code and the use of hugetlb_fault_mutex. With this modification, checks for races with truncation in the page fault path can be simplified and removed. remove_inode_hugepages no longer needs to take hugetlb_fault_mutex in the case of truncation. Comments are expanded to explain reasoning behind locking. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Prakash Sangappa <prakash.sangappa@oracle.com> Link: http://lkml.kernel.org/r/20200316205756.146666-3-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronizationMike Kravetz
Patch series "hugetlbfs: use i_mmap_rwsem for more synchronization", v2. While discussing the issue with huge_pte_offset [1], I remembered that there were more outstanding hugetlb races. These issues are: 1) For shared pmds, huge PTE pointers returned by huge_pte_alloc can become invalid via a call to huge_pmd_unshare by another thread. 2) hugetlbfs page faults can race with truncation causing invalid global reserve counts and state. A previous attempt was made to use i_mmap_rwsem in this manner as described at [2]. However, those patches were reverted starting with [3] due to locking issues. To effectively use i_mmap_rwsem to address the above issues it needs to be held (in read mode) during page fault processing. However, during fault processing we need to lock the page we will be adding. Lock ordering requires we take page lock before i_mmap_rwsem. Waiting until after taking the page lock is too late in the fault process for the synchronization we want to do. To address this lock ordering issue, the following patches change the lock ordering for hugetlb pages. This is not too invasive as hugetlbfs processing is done separate from core mm in many places. However, I don't really like this idea. Much ugliness is contained in the new routine hugetlb_page_mapping_lock_write() of patch 1. The only other way I can think of to address these issues is by catching all the races. After catching a race, cleanup, backout, retry ... etc, as needed. This can get really ugly, especially for huge page reservations. At one time, I started writing some of the reservation backout code for page faults and it got so ugly and complicated I went down the path of adding synchronization to avoid the races. Any other suggestions would be welcome. [1] https://lore.kernel.org/linux-mm/1582342427-230392-1-git-send-email-longpeng2@huawei.com/ [2] https://lore.kernel.org/linux-mm/20181222223013.22193-1-mike.kravetz@oracle.com/ [3] https://lore.kernel.org/linux-mm/20190103235452.29335-1-mike.kravetz@oracle.com [4] https://lore.kernel.org/linux-mm/1584028670.7365.182.camel@lca.pw/ [5] https://lore.kernel.org/lkml/20200312183142.108df9ac@canb.auug.org.au/ This patch (of 2): While looking at BUGs associated with invalid huge page map counts, it was discovered and observed that a huge pte pointer could become 'invalid' and point to another task's page table. Consider the following: A task takes a page fault on a shared hugetlbfs file and calls huge_pte_alloc to get a ptep. Suppose the returned ptep points to a shared pmd. Now, another task truncates the hugetlbfs file. As part of truncation, it unmaps everyone who has the file mapped. If the range being truncated is covered by a shared pmd, huge_pmd_unshare will be called. For all but the last user of the shared pmd, huge_pmd_unshare will clear the pud pointing to the pmd. If the task in the middle of the page fault is not the last user, the ptep returned by huge_pte_alloc now points to another task's page table or worse. This leads to bad things such as incorrect page map/reference counts or invalid memory references. To fix, expand the use of i_mmap_rwsem as follows: - i_mmap_rwsem is held in read mode whenever huge_pmd_share is called. huge_pmd_share is only called via huge_pte_alloc, so callers of huge_pte_alloc take i_mmap_rwsem before calling. In addition, callers of huge_pte_alloc continue to hold the semaphore until finished with the ptep. - i_mmap_rwsem is held in write mode whenever huge_pmd_unshare is called. One problem with this scheme is that it requires taking i_mmap_rwsem before taking the page lock during page faults. This is not the order specified in the rest of mm code. Handling of hugetlbfs pages is mostly isolated today. Therefore, we use this alternative locking order for PageHuge() pages. mapping->i_mmap_rwsem hugetlb_fault_mutex (hugetlbfs specific page fault mutex) page->flags PG_locked (lock_page) To help with lock ordering issues, hugetlb_page_mapping_lock_write() is introduced to write lock the i_mmap_rwsem associated with a page. In most cases it is easy to get address_space via vma->vm_file->f_mapping. However, in the case of migration or memory errors for anon pages we do not have an associated vma. A new routine _get_hugetlb_page_mapping() will use anon_vma to get address_space in these cases. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Prakash Sangappa <prakash.sangappa@oracle.com> Link: http://lkml.kernel.org/r/20200316205756.146666-2-mike.kravetz@oracle.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/memblock.c: remove redundant assignment to variable max_addrColin Ian King
The variable max_addr is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: http://lkml.kernel.org/r/20200228235003.112718-1-colin.king@canonical.com Addresses-Coverity: ("Unused value") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm: mempolicy: require at least one nodeid for MPOL_PREFERREDRandy Dunlap
Using an empty (malformed) nodelist that is not caught during mount option parsing leads to a stack-out-of-bounds access. The option string that was used was: "mpol=prefer:,". However, MPOL_PREFERRED requires a single node number, which is not being provided here. Add a check that 'nodes' is not empty after parsing for MPOL_PREFERRED's nodeid. Fixes: 095f1fc4ebf3 ("mempolicy: rework shmem mpol parsing and display") Reported-by: Entropy Moe <3ntr0py1337@gmail.com> Reported-by: syzbot+b055b1a6b2b958707a21@syzkaller.appspotmail.com Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: syzbot+b055b1a6b2b958707a21@syzkaller.appspotmail.com Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Link: http://lkml.kernel.org/r/89526377-7eb6-b662-e1d8-4430928abde9@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm: mempolicy: use VM_BUG_ON_VMA in queue_pages_test_walk()Yang Shi
The VM_BUG_ON() is already used by queue_pages_test_walk(), it sounds better to dump more debug information by using VM_BUG_ON_VMA() to help debugging. Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: "Li Xinhai" <lixinhai.lxh@gmail.com> Cc: Qian Cai <cai@lca.pw> Link: http://lkml.kernel.org/r/1579068565-110432-1-git-send-email-yang.shi@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/mempolicy: check hugepage migration is supported by arch in vma_migratable()Li Xinhai
vma_migratable() is called to check if pages in vma can be migrated before go ahead to further actions. Currently it is used in below code path: - task_numa_work - mbind - move_pages For hugetlb mapping, whether vma is migratable or not is determined by: - CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION - arch_hugetlb_migration_supported Issue: current code only checks for CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION alone, and no code should use it directly. (note that current code in vma_migratable don't cause failure or bug because unmap_and_move_huge_page() will catch unsupported hugepage and handle it properly) This patch checks the two factors by hugepage_migration_supported for impoving code logic and robustness. It will enable early bail out of hugepage migration procedure, but because currently all architecture supporting hugepage migration is able to support all page size, we would not see performance gain with this patch applied. vma_migratable() is moved to mm/mempolicy.c, because of the circular reference of mempolicy.h and hugetlb.h cause defining it as inline not feasible. Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Link: http://lkml.kernel.org/r/1579786179-30633-1-git-send-email-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/mempolicy: support MPOL_MF_STRICT for huge page mappingLi Xinhai
MPOL_MF_STRICT is used in mbind() for purposes: (1) MPOL_MF_STRICT is set alone without MPOL_MF_MOVE or MPOL_MF_MOVE_ALL, to check if there is misplaced page and return -EIO; (2) MPOL_MF_STRICT is set with MPOL_MF_MOVE or MPOL_MF_MOVE_ALL, to check if there is misplaced page which is failed to isolate, or page is success on isolate but failed to move, and return -EIO. For non hugepage mapping, (1) and (2) are implemented as expectation. For hugepage mapping, (1) is not implemented. And in (2), the part about failed to isolate and report -EIO is not implemented. This patch implements the missed parts for hugepage mapping. Benefits with it applied: - User space can apply same code logic to handle mbind() on hugepage and non hugepage mapping; - Reliably using MPOL_MF_STRICT alone to check whether there is misplaced page or not when bind policy on address range, especially for address range which contains both hugepage and non hugepage mapping. Analysis of potential impact to existing users: - If MPOL_MF_STRICT alone was previously used, hugetlb pages not following the memory policy would not cause an EIO error. After this change, hugetlb pages are treated like all other pages. If MPOL_MF_STRICT alone is used and hugetlb pages do not follow memory policy an EIO error will be returned. - For users who using MPOL_MF_STRICT with MPOL_MF_MOVE or MPOL_MF_MOVE_ALL, the semantic about some pages could not be moved will not be changed by this patch, because failed to isolate and failed to move have same effects to users, so their existing code will not be impacted. In mbind man page, the note about 'MPOL_MF_STRICT is ignored on huge page mappings' can be removed after this patch is applied. Mike: : The current behavior with MPOL_MF_STRICT and hugetlb pages is inconsistent : and does not match documentation (as described above). The special : behavior for hugetlb pages ideally should have been removed when hugetlb : page migration was introduced. It is unlikely that anyone relies on : today's inconsistent behavior, and removing one more case of special : handling for hugetlb pages is a good thing. Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: linux-man <linux-man@vger.kernel.org> Link: http://lkml.kernel.org/r/1581559627-6206-1-git-send-email-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/compaction.c: clean code by removing unnecessary assignmentMateusz Nosek
Previously 0 was assigned to variable 'last_migrated_pfn'. But the variable is not read after that, so the assignment can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Link: http://lkml.kernel.org/r/20200318174509.15021-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/compaction: Disable compact_unevictable_allowed on RTSebastian Andrzej Siewior
Since commit 5bbe3547aa3ba ("mm: allow compaction of unevictable pages") it is allowed to examine mlocked pages and compact them by default. On -RT even minor pagefaults are problematic because it may take a few 100us to resolve them and until then the task is blocked. Make compact_unevictable_allowed = 0 default and issue a warning on RT if it is changed. [bigeasy@linutronix.de: v5] Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/ Link: http://lkml.kernel.org/r/20200319165536.ovi75tsr2seared4@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/linux-mm/20190710144138.qyn4tuttdq6h7kqx@linutronix.de/ Link: http://lkml.kernel.org/r/20200303202225.nhqc3v5gwlb7x6et@linutronix.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm/compaction: really limit compact_unevictable_allowed to 0 and 1Sebastian Andrzej Siewior
The proc file `compact_unevictable_allowed' should allow 0 and 1 only, the `extra*' attribues have been set properly but without proc_dointvec_minmax() as the `proc_handler' the limit will not be enforced. Use proc_dointvec_minmax() as the `proc_handler' to enfoce the valid specified range. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Link: http://lkml.kernel.org/r/20200303202054.gsosv7fsx2ma3cic@linutronix.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm, compaction: fully assume capture is not NULL in compact_zone_order()Vlastimil Babka
Dan reports: The patch 5e1f0f098b46: "mm, compaction: capture a page under direct compaction" from Mar 5, 2019, leads to the following Smatch complaint: mm/compaction.c:2321 compact_zone_order() error: we previously assumed 'capture' could be null (see line 2313) mm/compaction.c 2288 static enum compact_result compact_zone_order(struct zone *zone, int order, 2289 gfp_t gfp_mask, enum compact_priority prio, 2290 unsigned int alloc_flags, int classzone_idx, 2291 struct page **capture) ^^^^^^^ 2313 if (capture) ^^^^^^^ Check for NULL 2314 current->capture_control = &capc; 2315 2316 ret = compact_zone(&cc, &capc); 2317 2318 VM_BUG_ON(!list_empty(&cc.freepages)); 2319 VM_BUG_ON(!list_empty(&cc.migratepages)); 2320 2321 *capture = capc.page; ^^^^^^^^ Unchecked dereference. 2322 current->capture_control = NULL; 2323 In practice this is not an issue, as the only caller path passes non-NULL capture: __alloc_pages_direct_compact() struct page *page = NULL; try_to_compact_pages(capture = &page); compact_zone_order(capture = capture); So let's remove the unnecessary check, which should also make Smatch happy. Fixes: 5e1f0f098b46 ("mm, compaction: capture a page under direct compaction") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Link: http://lkml.kernel.org/r/18b0df3c-0589-d96c-23fa-040798fee187@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm,thp,compaction,cma: allow THP migration for CMA allocationsRik van Riel
The code to implement THP migrations already exists, and the code for CMA to clear out a region of memory already exists. Only a few small tweaks are needed to allow CMA to move THP memory when attempting an allocation from alloc_contig_range. With these changes, migrating THPs from a CMA area works when allocating a 1GB hugepage from CMA memory. [riel@surriel.com: fix hugetlbfs pages per Mike, cleanup per Vlastimil] Link: http://lkml.kernel.org/r/20200228104700.0af2f18d@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Joonsoo Kim <js1304@gmail.com> Link: http://lkml.kernel.org/r/20200227213238.1298752-2-riel@surriel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02mm,compaction,cma: add alloc_contig flag to compact_controlRik van Riel
Patch series "fix THP migration for CMA allocations", v2. Transparent huge pages are allocated with __GFP_MOVABLE, and can end up in CMA memory blocks. Transparent huge pages also have most of the infrastructure in place to allow migration. However, a few pieces were missing, causing THP migration to fail when attempting to use CMA to allocate 1GB hugepages. With these patches in place, THP migration from CMA blocks seems to work, both for anonymous THPs and for tmpfs/shmem THPs. This patch (of 2): Add information to struct compact_control to indicate that the allocator would really like to clear out this specific part of memory, used by for example CMA. Signed-off-by: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Cc: Joonsoo Kim <js1304@gmail.com> Link: http://lkml.kernel.org/r/20200227213238.1298752-1-riel@surriel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-02selftests: vm: drop dependencies on page flags from mlock2 testsMichal Hocko
It was noticed that mlock2 tests are failing after 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs") because the patch has changed the timing on when the page is added to the unevictable LRU list and thus gains the unevictable page flag. The test was just too dependent on the implementation details which were true at the time when it was introduced. Page flags and the timing when they are set is something no userspace should ever depend on. The test should be testing only for the user observable contract of the tested syscalls. Those are defined pretty well for the mlock and there are other means for testing them. In fact this is already done and testing for page flags can be safely dropped to achieve the aimed purpose. Present bits can be checked by /proc/<pid>/smaps RSS field and the locking state by VmFlags although I would argue that Locked: field would be more appropriate. Drop all the page flag machinery and considerably simplify the test. This should be more robust for future kernel changes while checking the promised contract is still valid. Fixes: 9c4e6b1a7027f ("mm, mlock, vmscan: no more skipping pagevecs") Reported-by: Rafael Aquini <aquini@redhat.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Rafael Aquini <aquini@redhat.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Shuah Khan <shuah@kernel.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20200324154218.GS19542@dhcp22.suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>