kernel/linux.git/include/linux/vmalloc.h, branch linux-5.11.y

mm/vmalloc: separate put pages and flush VM flags

2021-02-05T19:03:47+00:00

When VM_MAP_PUT_PAGES was added, it was defined with the same value as VM_FLUSH_RESET_PERMS. This doesn't seem like it will cause any big functional problems other than some excess flushing for VM_MAP_PUT_PAGES allocations. Redefine VM_MAP_PUT_PAGES to have its own value. Also, rearrange things so flags are less likely to be missed in the future. Link: https://lkml.kernel.org/r/20210122233706.9304-1-rick.p.edgecombe@intel.com Fixes: b944afc9d64d ("mm: add a VM_MAP_PUT_PAGES flag for vmap") Signed-off-by: Rick Edgecombe Suggested-by: Matthew Wilcox Cc: Miaohe Lin Cc: Christoph Hellwig Cc: Daniel Axtens Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/vmalloc: rework the drain logic

2020-12-15T20:13:41+00:00

A current "lazy drain" model suffers from at least two issues. First one is related to the unsorted list of vmap areas, thus in order to identify the [min:max] range of areas to be drained, it requires a full list scan. What is a time consuming if the list is too long. Second one and as a next step is about merging all fragments with a free space. What is also a time consuming because it has to iterate over entire list which holds outstanding lazy areas. See below the "preemptirqsoff" tracer that illustrates a high latency. It is ~24676us. Our workloads like audio and video are effected by such long latency: tracer: preemptirqsoff preemptirqsoff latency trace v1.1.5 on 4.9.186-perf+ -------------------------------------------------------------------- latency: 24676 us, #4/4, CPU#1 | (M:preempt VP:0, KP:0, SP:0 HP:0 P:8) ----------------- | task: crtc_commit:112-261 (uid:0 nice:0 policy:1 rt_prio:16) ----------------- => started at: __purge_vmap_area_lazy => ended at: __purge_vmap_area_lazy _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / delay cmd pid ||||| time | caller \ / ||||| \ | / crtc_com-261 1...1 1us*: _raw_spin_lock <-__purge_vmap_area_lazy [...] crtc_com-261 1...1 24675us : _raw_spin_unlock <-__purge_vmap_area_lazy crtc_com-261 1...1 24677us : trace_preempt_on <-__purge_vmap_area_lazy crtc_com-261 1...1 24683us : => free_vmap_area_noflush => remove_vm_area => __vunmap => vfree => drm_property_free_blob => drm_mode_object_unreference => drm_property_unreference_blob => __drm_atomic_helper_crtc_destroy_state => sde_crtc_destroy_state => drm_atomic_state_default_clear => drm_atomic_state_clear => drm_atomic_state_free => complete_commit => _msm_drm_commit_work_cb => kthread_worker_fn => kthread => ret_from_fork To address those two issues we can redesign a purging of the outstanding lazy areas. Instead of queuing vmap areas to the list, we replace it by the separate rb-tree. In hat case an area is located in the tree/list in ascending order. It will give us below advantages: a) Outstanding vmap areas are merged creating bigger coalesced blocks, thus it becomes less fragmented. b) It is possible to calculate a flush range [min:max] without scanning all elements. It is O(1) access time or complexity; c) The final merge of areas with the rb-tree that represents a free space is faster because of (a). As a result the lock contention is also reduced. Link: https://lkml.kernel.org/r/20201116220033.1837-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Cc: Hillf Danton Cc: Michal Hocko Cc: Matthew Wilcox Cc: Oleksiy Avramchenko Cc: Steven Rostedt Cc: Minchan Kim Cc: huang ying Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove alloc_vm_area

2020-10-18T16:27:10+00:00

All users are gone now. Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Cc: Boris Ostrovsky Cc: Chris Wilson Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Juergen Gross Cc: Matthew Auld Cc: "Matthew Wilcox (Oracle)" Cc: Minchan Kim Cc: Nitin Gupta Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Stefano Stabellini Cc: Tvrtko Ursulin Cc: Uladzislau Rezki (Sony) Link: https://lkml.kernel.org/r/20201002122204.1534411-12-hch@lst.de Signed-off-by: Linus Torvalds

mm: add a vmap_pfn function

2020-10-18T16:27:10+00:00

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: Christoph Hellwig Signed-off-by: Andrew Morton Cc: Boris Ostrovsky Cc: Chris Wilson Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Juergen Gross Cc: Matthew Auld Cc: "Matthew Wilcox (Oracle)" Cc: Minchan Kim Cc: Nitin Gupta Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Stefano Stabellini Cc: Tvrtko Ursulin Cc: Uladzislau Rezki (Sony) Link: https://lkml.kernel.org/r/20201002122204.1534411-4-hch@lst.de Signed-off-by: Linus Torvalds

mm: add a VM_MAP_PUT_PAGES flag for vmap

2020-10-18T16:27:10+00:00

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: Christoph Hellwig Signed-off-by: Andrew Morton Cc: Boris Ostrovsky Cc: Chris Wilson Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Juergen Gross Cc: Matthew Auld Cc: "Matthew Wilcox (Oracle)" Cc: Minchan Kim Cc: Nitin Gupta Cc: Peter Zijlstra Cc: Rodrigo Vivi Cc: Stefano Stabellini Cc: Tvrtko Ursulin Cc: Uladzislau Rezki (Sony) Link: https://lkml.kernel.org/r/20201002122204.1534411-3-hch@lst.de Signed-off-by: Linus Torvalds

mm: remove vmalloc_exec

2020-06-26T07:27:38+00:00

Merge vmalloc_exec into its only caller. Note that for !CONFIG_MMU __vmalloc_node_range maps to __vmalloc, which directly clears the __GFP_HIGHMEM added by the vmalloc_exec stub anyway. Link: http://lkml.kernel.org/r/20200618064307.32739-4-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: David Hildenbrand Acked-by: Peter Zijlstra (Intel) Cc: Catalin Marinas Cc: Dexuan Cui Cc: Jessica Yu Cc: Vitaly Kuznetsov Cc: Wei Liu Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove vmalloc_sync_(un)mappings()

2020-06-02T17:59:12+00:00

These functions are not needed anymore because the vmalloc and ioremap mappings are now synchronized when they are created or torn down. Remove all callers and function definitions. Signed-off-by: Joerg Roedel Signed-off-by: Andrew Morton Tested-by: Steven Rostedt (VMware) Acked-by: Andy Lutomirski Acked-by: Peter Zijlstra (Intel) Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Dave Hansen Cc: "H . Peter Anvin" Cc: Ingo Molnar Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Thomas Gleixner Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200515140023.25469-7-joro@8bytes.org Signed-off-by: Linus Torvalds

mm/vmalloc: track which page-table levels were modified

2020-06-02T17:59:11+00:00

Track at which levels in the page-table entries were modified by vmap/vunmap. After the page-table has been modified, use that information do decide whether the new arch_sync_kernel_mappings() needs to be called. [akpm@linux-foundation.org: map_kernel_range_noflush() needs the arch_sync_kernel_mappings() call] Signed-off-by: Joerg Roedel Signed-off-by: Andrew Morton Acked-by: Andy Lutomirski Acked-by: Peter Zijlstra (Intel) Cc: Arnd Bergmann Cc: Christoph Hellwig Cc: Dave Hansen Cc: "H . Peter Anvin" Cc: Ingo Molnar Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: "Rafael J. Wysocki" Cc: Steven Rostedt (VMware) Cc: Thomas Gleixner Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/20200515140023.25469-3-joro@8bytes.org Signed-off-by: Linus Torvalds

mm: remove vmalloc_user_node_flags

2020-06-02T17:59:11+00:00

Open code it in __bpf_map_area_alloc, which is the only caller. Also clean up __bpf_map_area_alloc to have a single vmalloc call with slightly different flags instead of the current two different calls. For this to compile for the nommu case add a __vmalloc_node_range stub to nommu.c. [akpm@linux-foundation.org: fix nommu.c build] Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Peter Zijlstra (Intel) Acked-by: Johannes Weiner Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Daniel Vetter Cc: David Airlie Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: "K. Y. Srinivasan" Cc: Laura Abbott Cc: Mark Rutland Cc: Michael Kelley Cc: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Wei Liu Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Heiko Carstens Cc: Paul Mackerras Cc: Vasily Gorbik Cc: Will Deacon Cc: Stephen Rothwell Link: http://lkml.kernel.org/r/20200414131348.444715-27-hch@lst.de Signed-off-by: Linus Torvalds

mm: remove __vmalloc_node_flags_caller

2020-06-02T17:59:11+00:00

Just use __vmalloc_node instead which gets and extra argument. To be able to to use __vmalloc_node in all caller make it available outside of vmalloc and implement it in nommu.c. [akpm@linux-foundation.org: fix nommu build] Signed-off-by: Christoph Hellwig Signed-off-by: Andrew Morton Acked-by: Peter Zijlstra (Intel) Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Daniel Vetter Cc: David Airlie Cc: Gao Xiang Cc: Greg Kroah-Hartman Cc: Haiyang Zhang Cc: Johannes Weiner Cc: "K. Y. Srinivasan" Cc: Laura Abbott Cc: Mark Rutland Cc: Michael Kelley Cc: Minchan Kim Cc: Nitin Gupta Cc: Robin Murphy Cc: Sakari Ailus Cc: Stephen Hemminger Cc: Sumit Semwal Cc: Wei Liu Cc: Benjamin Herrenschmidt Cc: Catalin Marinas Cc: Heiko Carstens Cc: Paul Mackerras Cc: Vasily Gorbik Cc: Will Deacon Cc: Stephen Rothwell Link: http://lkml.kernel.org/r/20200414131348.444715-25-hch@lst.de Signed-off-by: Linus Torvalds