kernel.git/drivers/virtio/virtio_balloon.c, branch linux-rolling-lts

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2025-10-04T15:48:16Z

Pull virtio updates from Michael Tsirkin: "Just fixes and cleanups this time around. The mapping cleanups are preparing the ground for new features, though" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-vdpa: Drop redundant conversion to bool vduse: Use fixed 4KB bounce pages for non-4KB page size vduse: switch to use virtio map API instead of DMA API vdpa: introduce map ops vdpa: support virtio_map virtio: introduce map ops in virtio core virtio_ring: rename dma_handle to map_handle virtio: introduce virtio_map container union virtio: rename dma helpers virtio_ring: switch to use dma_{map|unmap}_page() virtio_ring: constify virtqueue pointer for DMA helpers virtio_balloon: Remove redundant __GFP_NOWARN vhost: vringh: Fix copy_to_iter return value check vhost: vringh: Modify the return value check

virtio_balloon: Remove redundant __GFP_NOWARN

2025-10-01T11:24:43Z

Commit 16f5dfbc851b ("gfp: include __GFP_NOWARN in GFP_NOWAIT") made GFP_NOWAIT implicitly include __GFP_NOWARN. Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT (e.g., `GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean up these redundant flags across subsystems. No functional changes. Signed-off-by: Qianfeng Rong Message-Id: <20250807132643.546237-1-rongqianfeng@vivo.com> Signed-off-by: Michael S. Tsirkin

virtio_balloon: stop calling page_address() in free_pages()

2025-09-21T21:22:18Z

free_pages() should be used when we only have a virtual address. We should call __free_pages() directly on our page instead. Link: https://lkml.kernel.org/r/20250903185921.1785167-8-vishal.moola@gmail.com Signed-off-by: Vishal Moola (Oracle) Acked-by: David Hildenbrand Acked-by: Michael S. Tsirkin Acked-by: Mike Rapoport (Microsoft) Cc: Albert Ou Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Dave Hansen Cc: Jens Axboe Cc: Justin Sanders Cc: Madhavan Srinivasan Cc: Matthew Wilcox (Oracle) Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Ritesh Harjani (IBM) Cc: SeongJae Park Cc: Will Deacon Signed-off-by: Andrew Morton

treewide: remove MIGRATEPAGE_SUCCESS

2025-09-13T23:54:50Z

At this point MIGRATEPAGE_SUCCESS is misnamed for all folio users, and now that we remove MIGRATEPAGE_UNMAP, it's really the only "success" return value that the code uses and expects. Let's just get rid of MIGRATEPAGE_SUCCESS completely and just use "0" for success. Link: https://lkml.kernel.org/r/20250811143949.1117439-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Zi Yan [mm] Acked-by: Dave Kleikamp [jfs] Acked-by: David Sterba [btrfs] Acked-by: Greg Kroah-Hartman Reviewed-by: Byungchul Park Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Benjamin LaHaise Cc: Chris Mason Cc: Christian Brauner Cc: Christophe Leroy Cc: Dave Kleikamp Cc: Eugenio Pé rez Cc: Gregory Price Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Wang Cc: Jerrin Shaji George Cc: Josef Bacik Cc: Joshua Hahn Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Minchan Kim Cc: Muchun Song Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Rakie Kim Cc: Sergey Senozhatsky Cc: Xuan Zhuo Cc: Lance Yang Signed-off-by: Andrew Morton

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2025-07-13T23:38:25Z

Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton

virtio_balloon: Use outer variable 'page'

2025-01-08T12:29:05Z

There is no need to define a local variable 'page', just use outer variable 'page'. Signed-off-by: zhang jiao Message-Id: <20241120054920.35291-1-zhangjiao2@cmss.chinamobile.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: David Hildenbrand Reviewed-by: Gavin Shan

virtio_balloon: introduce memory scan/reclaim info

2024-09-10T06:51:48Z

Expose memory scan/reclaim information to the host side via virtio balloon device. Now we have a metric to analyze the memory performance: y: counter increases n: counter does not changes h: the rate of counter change is high l: the rate of counter change is low OOM: VIRTIO_BALLOON_S_OOM_KILL STALL: VIRTIO_BALLOON_S_ALLOC_STALL ASCAN: VIRTIO_BALLOON_S_SCAN_ASYNC DSCAN: VIRTIO_BALLOON_S_SCAN_DIRECT ARCLM: VIRTIO_BALLOON_S_RECLAIM_ASYNC DRCLM: VIRTIO_BALLOON_S_RECLAIM_DIRECT - OOM[y], STALL[*], ASCAN[*], DSCAN[*], ARCLM[*], DRCLM[*]: the guest runs under really critial memory pressure - OOM[n], STALL[h], ASCAN[*], DSCAN[l], ARCLM[*], DRCLM[l]: the memory allocation stalls due to cgroup, not the global memory pressure. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[h]: the memory allocation stalls due to global memory pressure. The performance gets hurt a lot. A high ratio between DRCLM/DSCAN shows quite effective memory reclaiming. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[l]: the memory allocation stalls due to global memory pressure. the ratio between DRCLM/DSCAN gets low, the guest OS is thrashing heavily, the serious case leads poor performance and difficult trouble shooting. Ex, sshd may block on memory allocation when accepting new connections, a user can't login a VM by ssh command. - OOM[n], STALL[n], ASCAN[h], DSCAN[n], ARCLM[l], DRCLM[n]: the low ratio between ARCLM/ASCAN shows that the guest tries to reclaim more memory, but it can't. Once more memory is required in future, it will struggle to reclaim memory. Acked-by: David Hildenbrand Signed-off-by: zhenwei pi Message-Id: <20240423034109.1552866-5-pizhenwei@bytedance.com> Signed-off-by: Michael S. Tsirkin

virtio_balloon: introduce memory allocation stall counter

2024-09-10T06:51:47Z

Memory allocation stall counter represents the performance/latency of memory allocation, expose this counter to the host side by virtio balloon device via out-of-bound way. Acked-by: David Hildenbrand Signed-off-by: zhenwei pi Message-Id: <20240423034109.1552866-4-pizhenwei@bytedance.com> Signed-off-by: Michael S. Tsirkin

virtio_balloon: introduce oom-kill invocations

2024-09-10T06:51:47Z

When the guest OS runs under critical memory pressure, the guest starts to kill processes. A guest monitor agent may scan 'oom_kill' from /proc/vmstat, and reports the OOM KILL event. However, the agent may be killed and we will loss this critical event(and the later events). For now we can also grep for magic words in guest kernel log from host side. Rather than this unstable way, virtio balloon reports OOM-KILL invocations instead. Acked-by: David Hildenbrand Signed-off-by: zhenwei pi Message-Id: <20240423034109.1552866-3-pizhenwei@bytedance.com> Signed-off-by: Michael S. Tsirkin

virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

2024-07-17T09:20:58Z

Since the original virtio_find_vqs() is no longer present, rename virtio_find_vqs_info() back to virtio_find_vqs(). Signed-off-by: Jiri Pirko Message-Id: <20240708074814.1739223-20-jiri@resnulli.us> Signed-off-by: Michael S. Tsirkin