similar to: [PATCH RFCv1 0/5] mm/memory_hotplug: selective merging of memory resources

This is the follow-up of "[PATCH RFCv1 0/5] mm/memory_hotplug: selective merging of memory resources" [1] Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant

Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where

Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where

Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where

Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where

Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where

This series is based on [1]: [PATCH v2 00/10] virtio-mem: paravirtualized memory That will hopefull get picked up soon, rebased to -next. The following patches were reverted from -next [2]: [PATCH 0/3] kexec/memory_hotplug: Prevent removal and accidental use As discussed in that thread, they should be reverted from -next already. In theory, if people agree, we could take the first two patches

Clang warns: kernel/resource.c:1281:53: warning: operator '?:' has lower precedence than '|'; '|' will be evaluated first [-Wbitwise-conditional-parentheses] new_res = alloc_resource(GFP_KERNEL | alloc_nofail ? __GFP_NOFAIL : 0); ~~~~~~~~~~~~~~~~~~~~~~~~~ ^ kernel/resource.c:1281:53: note: place parentheses around the '|'

This is the follow up of [1]: [PATCH v1 0/3] mm/memory_hotplug: Make virtio-mem play nicely with kexec-tools I realized that this is not only helpful for virtio-mem, but also for dax/kmem - it's a fix for that use case (see patch #3) of persistent memory. Also, while testing, I discovered that kexec-tools will *not* add dax/kmem memory (anything not directly under the root when parsing

virtio-mem adds memory in memory block granularity, to be able to remove it in the same granularity again later, and to grow slowly on demand. This, however, results in quite a lot of resources when adding a lot of memory. Resources are effectively stored in a list-based tree. Having a lot of resources not only wastes memory, it also makes traversing that tree more expensive, and makes /proc/iomem

Virtio-mem managed memory is always detected and added by the virtio-mem driver, never using something like the firmware-provided memory map. This is the case after an ordinary system reboot, and has to be guaranteed after kexec. Especially, virtio-mem added memory resources can contain inaccessible parts ("unblocked memory blocks"), blindly forwarding them to a kexec kernel is

Virtio-mem managed memory is always detected and added by the virtio-mem driver, never using something like the firmware-provided memory map. This is the case after an ordinary system reboot, and has to be guaranteed after kexec. Especially, virtio-mem added memory resources can contain inaccessible parts ("unblocked memory blocks"), blindly forwarding them to a kexec kernel is

This series is based on v5.7-rc4. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v4 This is basically a resend of v3 [1], now based on v5.7-rc4 and restested. One patch was reshuffled and two ACKs I missed to add were added. The rebase did not require any modifications to patches. Details about virtio-mem can be found in the cover letter of v2 [2]. A

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v3 Patch #1 - #10 where contained in v2 and only contain minor modifications (mostly smaller fixes). The remaining patches are new and contain smaller optimizations. Details about virtio-mem can be found in the cover letter of v2 [1]. A basic QEMU implementation was

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v2 I now have acks for all !virtio-mem changes. I'll be happy to get review feedback, testing reports, etc. for the virtio-mem changes. If there are no further comments, I guess this is good to go as a v1 soon. The basic idea of virtio-mem is to provide a

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-rfc-v4 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. This

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v1 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. It's

This series is based on latest linux-next. The patches are located at: https://github.com/davidhildenbrand/linux.git virtio-mem-v1 The basic idea of virtio-mem is to provide a flexible, cross-architecture memory hot(un)plug solution that avoids many limitations imposed by existing technologies, architectures, and interfaces. More details can be found below and in linked material. It's