Re: [PATCH 4/6] kernel: move use_mm/unuse_mm to kthread.c
From: Felix Kuehling
Date: Mon Apr 06 2020 - 12:11:08 EST
Am 2020-04-04 um 5:40 a.m. schrieb Christoph Hellwig:
> These helpers are only for use with kernel threads, and I will tie them
> more into the kthread infrastructure going forward. Also move the
> prototypes to kthread.h - mmu_context.h was a little weird to start with
> as it otherwise contains very low-level MM bits.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Thanks for cleaning up the unnecessary includes in amdgpu.
Regards,
 Felix
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 1 +
> .../drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c | 1 -
> .../drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c | 1 -
> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c | 2 -
> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c | 2 -
> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c | 2 -
> drivers/gpu/drm/i915/gvt/kvmgt.c | 2 +-
> drivers/usb/gadget/function/f_fs.c | 2 +-
> drivers/usb/gadget/legacy/inode.c | 2 +-
> drivers/vhost/vhost.c | 1 -
> fs/aio.c | 1 -
> fs/io-wq.c | 1 -
> fs/io_uring.c | 1 -
> include/linux/kthread.h | 5 ++
> include/linux/mmu_context.h | 5 --
> kernel/kthread.c | 56 ++++++++++++++++
> mm/Makefile | 2 +-
> mm/mmu_context.c | 64 -------------------
> 18 files changed, 66 insertions(+), 85 deletions(-)
> delete mode 100644 mm/mmu_context.c
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> index 4db143c19dcc..bce5e93fefc8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> @@ -27,6 +27,7 @@
>
> #include <linux/types.h>
> #include <linux/mm.h>
> +#include <linux/kthread.h>
> #include <linux/workqueue.h>
> #include <kgd_kfd_interface.h>
> #include <drm/ttm/ttm_execbuf_util.h>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> index 6529caca88fe..35d4a5ab0228 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_arcturus.c
> @@ -22,7 +22,6 @@
> #include <linux/module.h>
> #include <linux/fdtable.h>
> #include <linux/uaccess.h>
> -#include <linux/mmu_context.h>
> #include <linux/firmware.h>
> #include "amdgpu.h"
> #include "amdgpu_amdkfd.h"
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> index 4ec6d0c03201..b1655054b919 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v10.c
> @@ -19,7 +19,6 @@
> * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> * OTHER DEALINGS IN THE SOFTWARE.
> */
> -#include <linux/mmu_context.h>
> #include "amdgpu.h"
> #include "amdgpu_amdkfd.h"
> #include "gc/gc_10_1_0_offset.h"
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
> index 0b7e78748540..7d01420c0c85 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v7.c
> @@ -20,8 +20,6 @@
> * OTHER DEALINGS IN THE SOFTWARE.
> */
>
> -#include <linux/mmu_context.h>
> -
> #include "amdgpu.h"
> #include "amdgpu_amdkfd.h"
> #include "cikd.h"
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
> index ccd635b812b5..635cd1a26bed 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v8.c
> @@ -20,8 +20,6 @@
> * OTHER DEALINGS IN THE SOFTWARE.
> */
>
> -#include <linux/mmu_context.h>
> -
> #include "amdgpu.h"
> #include "amdgpu_amdkfd.h"
> #include "gfx_v8_0.h"
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> index df841c2ac5e7..c7fd0c47b254 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gfx_v9.c
> @@ -19,8 +19,6 @@
> * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
> * OTHER DEALINGS IN THE SOFTWARE.
> */
> -#include <linux/mmu_context.h>
> -
> #include "amdgpu.h"
> #include "amdgpu_amdkfd.h"
> #include "gc/gc_9_0_offset.h"
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 5848400620b4..dee01c371bf5 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -31,7 +31,7 @@
> #include <linux/init.h>
> #include <linux/device.h>
> #include <linux/mm.h>
> -#include <linux/mmu_context.h>
> +#include <linux/kthread.h>
> #include <linux/sched/mm.h>
> #include <linux/types.h>
> #include <linux/list.h>
> diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
> index c81023b195c3..c57b1b2507c6 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -32,7 +32,7 @@
> #include <linux/usb/functionfs.h>
>
> #include <linux/aio.h>
> -#include <linux/mmu_context.h>
> +#include <linux/kthread.h>
> #include <linux/poll.h>
> #include <linux/eventfd.h>
>
> diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
> index aa0de9e35afa..8b5233888bf8 100644
> --- a/drivers/usb/gadget/legacy/inode.c
> +++ b/drivers/usb/gadget/legacy/inode.c
> @@ -21,7 +21,7 @@
> #include <linux/sched.h>
> #include <linux/slab.h>
> #include <linux/poll.h>
> -#include <linux/mmu_context.h>
> +#include <linux/kthread.h>
> #include <linux/aio.h>
> #include <linux/uio.h>
> #include <linux/refcount.h>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index f44340b41494..4e9ce54869af 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -14,7 +14,6 @@
> #include <linux/vhost.h>
> #include <linux/uio.h>
> #include <linux/mm.h>
> -#include <linux/mmu_context.h>
> #include <linux/miscdevice.h>
> #include <linux/mutex.h>
> #include <linux/poll.h>
> diff --git a/fs/aio.c b/fs/aio.c
> index 5f3d3d814928..328829f0343b 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -27,7 +27,6 @@
> #include <linux/file.h>
> #include <linux/mm.h>
> #include <linux/mman.h>
> -#include <linux/mmu_context.h>
> #include <linux/percpu.h>
> #include <linux/slab.h>
> #include <linux/timer.h>
> diff --git a/fs/io-wq.c b/fs/io-wq.c
> index cc5cf2209fb0..c49c2bdbafb5 100644
> --- a/fs/io-wq.c
> +++ b/fs/io-wq.c
> @@ -10,7 +10,6 @@
> #include <linux/errno.h>
> #include <linux/sched/signal.h>
> #include <linux/mm.h>
> -#include <linux/mmu_context.h>
> #include <linux/sched/mm.h>
> #include <linux/percpu.h>
> #include <linux/slab.h>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 358f97be9c7b..27a4ecb724ca 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -55,7 +55,6 @@
> #include <linux/fdtable.h>
> #include <linux/mm.h>
> #include <linux/mman.h>
> -#include <linux/mmu_context.h>
> #include <linux/percpu.h>
> #include <linux/slab.h>
> #include <linux/kthread.h>
> diff --git a/include/linux/kthread.h b/include/linux/kthread.h
> index 8bbcaad7ef0f..c2d40c9672d6 100644
> --- a/include/linux/kthread.h
> +++ b/include/linux/kthread.h
> @@ -5,6 +5,8 @@
> #include <linux/err.h>
> #include <linux/sched.h>
>
> +struct mm_struct;
> +
> __printf(4, 5)
> struct task_struct *kthread_create_on_node(int (*threadfn)(void *data),
> void *data,
> @@ -198,6 +200,9 @@ bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work);
>
> void kthread_destroy_worker(struct kthread_worker *worker);
>
> +void use_mm(struct mm_struct *mm);
> +void unuse_mm(struct mm_struct *mm);
> +
> struct cgroup_subsys_state;
>
> #ifdef CONFIG_BLK_CGROUP
> diff --git a/include/linux/mmu_context.h b/include/linux/mmu_context.h
> index d9a543a9e1cc..c51a84132d7c 100644
> --- a/include/linux/mmu_context.h
> +++ b/include/linux/mmu_context.h
> @@ -4,11 +4,6 @@
>
> #include <asm/mmu_context.h>
>
> -struct mm_struct;
> -
> -void use_mm(struct mm_struct *mm);
> -void unuse_mm(struct mm_struct *mm);
> -
> /* Architectures that care about IRQ state in switch_mm can override this. */
> #ifndef switch_mm_irqs_off
> # define switch_mm_irqs_off switch_mm
> diff --git a/kernel/kthread.c b/kernel/kthread.c
> index bfbfa481be3a..ce4610316377 100644
> --- a/kernel/kthread.c
> +++ b/kernel/kthread.c
> @@ -1,13 +1,17 @@
> // SPDX-License-Identifier: GPL-2.0-only
> /* Kernel thread helper functions.
> * Copyright (C) 2004 IBM Corporation, Rusty Russell.
> + * Copyright (C) 2009 Red Hat, Inc.
> *
> * Creation is done via kthreadd, so that we get a clean environment
> * even if we're invoked from userspace (think modprobe, hotplug cpu,
> * etc.).
> */
> #include <uapi/linux/sched/types.h>
> +#include <linux/mm.h>
> +#include <linux/mmu_context.h>
> #include <linux/sched.h>
> +#include <linux/sched/mm.h>
> #include <linux/sched/task.h>
> #include <linux/kthread.h>
> #include <linux/completion.h>
> @@ -25,6 +29,7 @@
> #include <linux/numa.h>
> #include <trace/events/sched.h>
>
> +
> static DEFINE_SPINLOCK(kthread_create_lock);
> static LIST_HEAD(kthread_create_list);
> struct task_struct *kthreadd_task;
> @@ -1203,6 +1208,57 @@ void kthread_destroy_worker(struct kthread_worker *worker)
> }
> EXPORT_SYMBOL(kthread_destroy_worker);
>
> +/*
> + * use_mm
> + * Makes the calling kernel thread take on the specified
> + * mm context.
> + * (Note: this routine is intended to be called only
> + * from a kernel thread context)
> + */
> +void use_mm(struct mm_struct *mm)
> +{
> + struct mm_struct *active_mm;
> + struct task_struct *tsk = current;
> +
> + task_lock(tsk);
> + active_mm = tsk->active_mm;
> + if (active_mm != mm) {
> + mmgrab(mm);
> + tsk->active_mm = mm;
> + }
> + tsk->mm = mm;
> + switch_mm(active_mm, mm, tsk);
> + task_unlock(tsk);
> +#ifdef finish_arch_post_lock_switch
> + finish_arch_post_lock_switch();
> +#endif
> +
> + if (active_mm != mm)
> + mmdrop(active_mm);
> +}
> +EXPORT_SYMBOL_GPL(use_mm);
> +
> +/*
> + * unuse_mm
> + * Reverses the effect of use_mm, i.e. releases the
> + * specified mm context which was earlier taken on
> + * by the calling kernel thread
> + * (Note: this routine is intended to be called only
> + * from a kernel thread context)
> + */
> +void unuse_mm(struct mm_struct *mm)
> +{
> + struct task_struct *tsk = current;
> +
> + task_lock(tsk);
> + sync_mm_rss(mm);
> + tsk->mm = NULL;
> + /* active_mm is still 'mm' */
> + enter_lazy_tlb(mm, tsk);
> + task_unlock(tsk);
> +}
> +EXPORT_SYMBOL_GPL(unuse_mm);
> +
> #ifdef CONFIG_BLK_CGROUP
> /**
> * kthread_associate_blkcg - associate blkcg to current kthread
> diff --git a/mm/Makefile b/mm/Makefile
> index dbc8346d16ca..0af4ee81aed2 100644
> --- a/mm/Makefile
> +++ b/mm/Makefile
> @@ -41,7 +41,7 @@ obj-y := filemap.o mempool.o oom_kill.o fadvise.o \
> maccess.o page-writeback.o \
> readahead.o swap.o truncate.o vmscan.o shmem.o \
> util.o mmzone.o vmstat.o backing-dev.o \
> - mm_init.o mmu_context.o percpu.o slab_common.o \
> + mm_init.o percpu.o slab_common.o \
> compaction.o vmacache.o \
> interval_tree.o list_lru.o workingset.o \
> debug.o gup.o $(mmu-y)
> diff --git a/mm/mmu_context.c b/mm/mmu_context.c
> deleted file mode 100644
> index 3e612ae748e9..000000000000
> --- a/mm/mmu_context.c
> +++ /dev/null
> @@ -1,64 +0,0 @@
> -/* Copyright (C) 2009 Red Hat, Inc.
> - *
> - * See ../COPYING for licensing terms.
> - */
> -
> -#include <linux/mm.h>
> -#include <linux/sched.h>
> -#include <linux/sched/mm.h>
> -#include <linux/sched/task.h>
> -#include <linux/mmu_context.h>
> -#include <linux/export.h>
> -
> -#include <asm/mmu_context.h>
> -
> -/*
> - * use_mm
> - * Makes the calling kernel thread take on the specified
> - * mm context.
> - * (Note: this routine is intended to be called only
> - * from a kernel thread context)
> - */
> -void use_mm(struct mm_struct *mm)
> -{
> - struct mm_struct *active_mm;
> - struct task_struct *tsk = current;
> -
> - task_lock(tsk);
> - active_mm = tsk->active_mm;
> - if (active_mm != mm) {
> - mmgrab(mm);
> - tsk->active_mm = mm;
> - }
> - tsk->mm = mm;
> - switch_mm(active_mm, mm, tsk);
> - task_unlock(tsk);
> -#ifdef finish_arch_post_lock_switch
> - finish_arch_post_lock_switch();
> -#endif
> -
> - if (active_mm != mm)
> - mmdrop(active_mm);
> -}
> -EXPORT_SYMBOL_GPL(use_mm);
> -
> -/*
> - * unuse_mm
> - * Reverses the effect of use_mm, i.e. releases the
> - * specified mm context which was earlier taken on
> - * by the calling kernel thread
> - * (Note: this routine is intended to be called only
> - * from a kernel thread context)
> - */
> -void unuse_mm(struct mm_struct *mm)
> -{
> - struct task_struct *tsk = current;
> -
> - task_lock(tsk);
> - sync_mm_rss(mm);
> - tsk->mm = NULL;
> - /* active_mm is still 'mm' */
> - enter_lazy_tlb(mm, tsk);
> - task_unlock(tsk);
> -}
> -EXPORT_SYMBOL_GPL(unuse_mm);