Re: [PATCH 24/25] mm: remove the HMM config option

Ira Weiny
2019-06-26T21:38:23Z

On Wed, Jun 26, 2019 at 02:27:23PM +0200, Christoph Hellwig wrote:
> All the mm/hmm.c code is better keyed off HMM_MIRROR. Also let nouveau
> depend on it instead of the mix of a dummy dependency symbol plus the
> actually selected one. Drop various odd dependencies, as the code is
> pretty portable.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Seems reasonable to me.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
> drivers/gpu/drm/nouveau/Kconfig | 3 +--
> include/linux/hmm.h | 5 +----
> include/linux/mm_types.h | 2 +-
> mm/Kconfig | 27 ++++-----------------------
> mm/Makefile | 2 +-
> mm/hmm.c | 2 --
> 6 files changed, 8 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/Kconfig b/drivers/gpu/drm/nouveau/Kconfig
> index 6303d203ab1d..66c839d8e9d1 100644
> --- a/drivers/gpu/drm/nouveau/Kconfig
> +++ b/drivers/gpu/drm/nouveau/Kconfig
> @@ -84,11 +84,10 @@ config DRM_NOUVEAU_BACKLIGHT
>
> config DRM_NOUVEAU_SVM
> bool "(EXPERIMENTAL) Enable SVM (Shared Virtual Memory) support"
> - depends on ARCH_HAS_HMM
> depends on DEVICE_PRIVATE
> depends on DRM_NOUVEAU
> + depends on HMM_MIRROR
> depends on STAGING
> - select HMM_MIRROR
> default n
> help
> Say Y here if you want to enable experimental support for
> diff --git a/include/linux/hmm.h b/include/linux/hmm.h
> index 3d00e9550e77..b697496e85ba 100644
> --- a/include/linux/hmm.h
> +++ b/include/linux/hmm.h
> @@ -62,7 +62,7 @@
> #include <linux/kconfig.h>
> #include <asm/pgtable.h>
>
> -#if IS_ENABLED(CONFIG_HMM)
> +#ifdef CONFIG_HMM_MIRROR
>
> #include <linux/device.h>
> #include <linux/migrate.h>
> @@ -332,9 +332,6 @@ static inline uint64_t hmm_pfn_from_pfn(const struct hmm_range *range,
> return hmm_device_entry_from_pfn(range, pfn);
> }
>
> -
> -
> -#if IS_ENABLED(CONFIG_HMM_MIRROR)
> /*
> * Mirroring: how to synchronize device page table with CPU page table.
> *
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index f33a1289c101..8d37182f8dbe 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -501,7 +501,7 @@ struct mm_struct {
> #endif
> struct work_struct async_put_work;
>
> -#if IS_ENABLED(CONFIG_HMM)
> +#ifdef CONFIG_HMM_MIRROR
> /* HMM needs to track a few things per mm */
> struct hmm *hmm;
> #endif
> diff --git a/mm/Kconfig b/mm/Kconfig
> index eecf037a54b3..1e426c26b1d6 100644
> --- a/mm/Kconfig
> +++ b/mm/Kconfig
> @@ -669,37 +669,18 @@ config ZONE_DEVICE
>
> If FS_DAX is enabled, then say Y.
>
> -config ARCH_HAS_HMM_MIRROR
> - bool
> - default y
> - depends on (X86_64 || PPC64)
> - depends on MMU && 64BIT
> -
> -config ARCH_HAS_HMM
> - bool
> - depends on (X86_64 || PPC64)
> - depends on ZONE_DEVICE
> - depends on MMU && 64BIT
> - depends on MEMORY_HOTPLUG
> - depends on MEMORY_HOTREMOVE
> - depends on SPARSEMEM_VMEMMAP
> - default y
> -
> config MIGRATE_VMA_HELPER
> bool
>
> config DEV_PAGEMAP_OPS
> bool
>
> -config HMM
> - bool
> - select MMU_NOTIFIER
> - select MIGRATE_VMA_HELPER
> -
> config HMM_MIRROR
> bool "HMM mirror CPU page table into a device page table"
> - depends on ARCH_HAS_HMM
> - select HMM
> + depends on (X86_64 || PPC64)
> + depends on MMU && 64BIT
> + select MMU_NOTIFIER
> + select MIGRATE_VMA_HELPER
> help
> Select HMM_MIRROR if you want to mirror range of the CPU page table of a
> process into a device page table. Here, mirror means "keep synchronized".
> diff --git a/mm/Makefile b/mm/Makefile
> index ac5e5ba78874..91c99040065c 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -102,5 +102,5 @@ obj-$(CONFIG_FRAME_VECTOR) += frame_vector.o
> obj-$(CONFIG_DEBUG_PAGE_REF) += debug_page_ref.o
> obj-$(CONFIG_HARDENED_USERCOPY) += usercopy.o
> obj-$(CONFIG_PERCPU_STATS) += percpu-stats.o
> -obj-$(CONFIG_HMM) += hmm.o
> +obj-$(CONFIG_HMM_MIRROR) += hmm.o
> obj-$(CONFIG_MEMFD_CREATE) += memfd.o
> diff --git a/mm/hmm.c b/mm/hmm.c
> index 90ca0cdab9db..d62ce64d6bca 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -25,7 +25,6 @@
> #include <linux/mmu_notifier.h>
> #include <linux/memory_hotplug.h>
>
> -#if IS_ENABLED(CONFIG_HMM_MIRROR)
> static const struct mmu_notifier_ops hmm_mmu_notifier_ops;
>
> static inline struct hmm *mm_get_hmm(struct mm_struct *mm)
> @@ -1326,4 +1325,3 @@ long hmm_range_dma_unmap(struct hmm_range *range,
> return cpages;
> }
> EXPORT_SYMBOL(hmm_range_dma_unmap);
> -#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
> --
> 2.20.1
>
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