[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qe
From: |
Eduardo Habkost |
Subject: |
Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap() |
Date: |
Tue, 30 Apr 2019 17:46:36 -0300 |
User-agent: |
Mutt/1.10.1 (2018-07-13) |
Hi,
On Fri, Apr 26, 2019 at 08:36:51AM +0800, Wei Yang wrote:
> From: Zhang Yi <address@hidden>
>
> When a file supporting DAX is used as vNVDIMM backend, mmap it with
> MAP_SYNC flag in addition which can ensure file system metadata
> synced in each guest writes to the backend file, without other QEMU
> actions (e.g., periodic fsync() by QEMU).
>
> Current, We have below different possible use cases:
>
> 1. pmem=on is set, shared=on is set, MAP_SYNC supported:
> a: backend is a dax supporting file.
> - MAP_SYNC will active.
> b: backend is not a dax supporting file.
> - mmap will trigger a warning. then MAP_SYNC flag will be ignored
>
> 2. The rest of cases:
> - we will never pass the MAP_SYNC to mmap2
>
> Signed-off-by: Haozhong Zhang <address@hidden>
> Signed-off-by: Zhang Yi <address@hidden>
> [ehabkost: Rebased patch to latest code on master]
> Signed-off-by: Eduardo Habkost <address@hidden>
> Signed-off-by: Wei Yang <address@hidden>
> Tested-by: Wei Yang <address@hidden>
> Reviewed-by: Stefan Hajnoczi <address@hidden>
>
> ---
> v15: fix compile issue on pre-linux4.15
> v14: rebase on top of current upstream
Note that v14 was already merged, so the build fix would need to
be submitted separately. However:
[...]
> +#ifdef CONFIG_LINUX
> +#include <linux/mman.h>
> +#endif /* CONFIG_LINUX */
> +
> +#ifndef MAP_SYNC
> +#define MAP_SYNC 0
> +#endif
> +#ifndef MAP_SHARED_VALIDATE
> +#define MAP_SHARED_VALIDATE 0
> +#endif
Why would we need this, if we added copies of mman.h to
linux-headers?
--
Eduardo
- [Qemu-devel] [PATCH v15 0/2] support MAP_SYNC for memory-backend-file, Wei Yang, 2019/04/25
- [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Wei Yang, 2019/04/25
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(),
Eduardo Habkost <=
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Wei Yang, 2019/04/30
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Eduardo Habkost, 2019/04/30
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Michael S. Tsirkin, 2019/04/30
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Paolo Bonzini, 2019/04/30
- Re: [Qemu-devel] [PATCH v15 1/2] util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap(), Michael S. Tsirkin, 2019/04/30
[Qemu-devel] [PATCH v15 2/2] docs: Added MAP_SYNC documentation, Wei Yang, 2019/04/25