linux/Documentation/vm, branch v5.6

mm/zswap.c: add allocation hysteresis if pool limit is hit

2020-01-31T18:30:39Z

zswap will always try to shrink pool when zswap is full. If there is a high pressure on zswap it will result in flipping pages in and out zswap pool without any real benefit, and the overall system performance will drop. The previous discussion on this subject [1] ended up with a suggestion to implement a sort of hysteresis to refuse taking pages into zswap pool until it has sufficient space if the limit has been hit. This is my take on this. Hysteresis is controlled with a sysfs-configurable parameter (namely, /sys/kernel/debug/zswap/accept_threhsold_percent). It specifies the threshold at which zswap would start accepting pages again after it became full. Setting this parameter to 100 disables the hysteresis and sets the zswap behavior to pre-hysteresis state. [1] https://lkml.org/lkml/2019/11/8/949 Link: http://lkml.kernel.org/r/20200108200118.15563-1-vitaly.wool@konsulko.com Signed-off-by: Vitaly Wool Cc: Dan Streetman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/mmu_notifiers: Use 'interval_sub' as the variable for mmu_interval_notifier

2020-01-14T15:54:47Z

The 'interval_sub' is placed on the 'notifier_subscriptions' interval tree. This eliminates the poor name 'mni' for this variable. Signed-off-by: Jason Gunthorpe

mm/hmm: remove hmm_mirror and related

2019-11-23T23:56:45Z

The only two users of this are now converted to use mmu_interval_notifier, delete all the code and update hmm.rst. Link: https://lore.kernel.org/r/20191112202231.3856-14-jgg@ziepe.ca Reviewed-by: Jérôme Glisse Tested-by: Ralph Campbell Reviewed-by: Christoph Hellwig Signed-off-by: Jason Gunthorpe

mm: treewide: clarify pgtable_page_{ctor,dtor}() naming

2019-09-26T17:10:44Z

The naming of pgtable_page_{ctor,dtor}() seems to have confused a few people, and until recently arm64 used these erroneously/pointlessly for other levels of page table. To make it incredibly clear that these only apply to the PTE level, and to align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them to pgtable_pte_page_{ctor,dtor}(). These changes were generated with the following shell script: ---- git grep -lw 'pgtable_page_.tor' | while read FILE; do sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE; sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE; done ---- ... with the documentation re-flowed to remain under 80 columns, and whitespace fixed up in macros to keep backslashes aligned. There should be no functional change as a result of this patch. Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.com Signed-off-by: Mark Rutland Reviewed-by: Mike Rapoport Acked-by: Geert Uytterhoeven [m68k] Cc: Anshuman Khandual Cc: Matthew Wilcox Cc: Michal Hocko Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'odp_fixes' into hmm.git

2019-08-21T23:58:18Z

From rdma.git Jason Gunthorpe says: ==================== This is a collection of general cleanups for ODP to clarify some of the flows around umem creation and use of the interval tree. ==================== The branch is based on v5.3-rc5 due to dependencies, and is being taken into hmm.git due to dependencies in the next patches. * odp_fixes: RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr RDMA/mlx5: Use ib_umem_start instead of umem.address RDMA/core: Make invalidate_range a device operation RDMA/odp: Use kvcalloc for the dma_list and page_list RDMA/odp: Check for overflow when computing the umem_odp end RDMA/odp: Provide ib_umem_odp_release() to undo the allocs RDMA/odp: Split creating a umem_odp from ib_umem_get RDMA/odp: Make the three ways to create a umem_odp clear RMDA/odp: Consolidate umem_odp initialization RDMA/odp: Make it clearer when a umem is an implicit ODP umem RDMA/odp: Iterate over the whole rbtree directly RDMA/odp: Use the common interval tree library instead of generic RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB Signed-off-by: Jason Gunthorpe

mm: turn migrate_vma upside down

2019-08-20T12:35:02Z

There isn't any good reason to pass callbacks to migrate_vma. Instead we can just export the three steps done by this function to drivers and let them sequence the operation without callbacks. This removes a lot of boilerplate code as-is, and will allow the drivers to drastically improve code flow and error handling further on. Link: https://lore.kernel.org/r/20190814075928.23766-2-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Ralph Campbell Tested-by: Ralph Campbell Signed-off-by: Jason Gunthorpe

mm/hmm: remove superfluous arguments from hmm_range_register

2019-08-07T17:58:05Z

The start, end and page_shift values are all saved in the range structure, so we might as well use that for argument passing. Link: https://lore.kernel.org/r/20190806160554.14046-7-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Reviewed-by: Felix Kuehling Signed-off-by: Jason Gunthorpe

Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2019-07-30T19:54:44Z

Pull HMM fixes from Jason Gunthorpe: "Fix the locking around nouveau's use of the hmm_range_* APIs. It works correctly in the success case, but many of the the edge cases have missing unlocks or double unlocks. The diffstat is a bit big as Christoph did a comprehensive job to move the obsolete API from the core header and into the driver before fixing its flow, but the risk of regression from this code motion is low" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: nouveau: unlock mmap_sem on all errors from nouveau_range_fault nouveau: remove the block parameter to nouveau_range_fault mm/hmm: move hmm_vma_range_done and hmm_vma_fault to nouveau mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}

mm/hmm: merge hmm_range_snapshot into hmm_range_fault

2019-07-26T14:10:53Z

Add a HMM_FAULT_SNAPSHOT flag so that hmm_range_snapshot can be merged into the almost identical hmm_range_fault function. Link: https://lore.kernel.org/r/20190726005650.2566-5-rcampbell@nvidia.com Signed-off-by: Christoph Hellwig Signed-off-by: Ralph Campbell Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe

mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}

2019-07-25T19:14:39Z

We should not have two different error codes for the same condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry case and signals to the caller that the mmap_sem has been unlocked. Use EBUSY for the !valid case so that callers can get the locking right. Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.de Tested-by: Ralph Campbell Signed-off-by: Christoph Hellwig Reviewed-by: Ralph Campbell Reviewed-by: Jason Gunthorpe Reviewed-by: Felix Kuehling [jgg: elaborated commit message] Signed-off-by: Jason Gunthorpe