From: Rob Clark <robdclark@gmail.com>
To: dri-devel@lists.freedesktop.org
Cc: linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org,
Rob Clark <robdclark@chromium.org>,
"Kristian H . Kristensen" <hoegsberg@google.com>,
Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v4 06/23] drm/msm/gem: Move locking in shrinker path
Date: Fri, 23 Oct 2020 09:51:07 -0700 [thread overview]
Message-ID: <20201023165136.561680-7-robdclark@gmail.com> (raw)
In-Reply-To: <20201023165136.561680-1-robdclark@gmail.com>
From: Rob Clark <robdclark@chromium.org>
Move grabbing the bo lock into shrinker, with a msm_gem_trylock() to
skip over bo's that are already locked. This gets rid of the nested
lock classes.
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
---
drivers/gpu/drm/msm/msm_gem.c | 24 +++++----------------
drivers/gpu/drm/msm/msm_gem.h | 29 ++++++++++----------------
drivers/gpu/drm/msm/msm_gem_shrinker.c | 27 +++++++++++++++++-------
3 files changed, 35 insertions(+), 45 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index e0d8d739b068..1195847714ba 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -17,8 +17,6 @@
#include "msm_gpu.h"
#include "msm_mmu.h"
-static void msm_gem_vunmap_locked(struct drm_gem_object *obj);
-
static dma_addr_t physaddr(struct drm_gem_object *obj)
{
@@ -693,20 +691,19 @@ int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv)
return (madv != __MSM_MADV_PURGED);
}
-void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass)
+void msm_gem_purge(struct drm_gem_object *obj)
{
struct drm_device *dev = obj->dev;
struct msm_gem_object *msm_obj = to_msm_bo(obj);
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+ WARN_ON(!msm_gem_is_locked(obj));
WARN_ON(!is_purgeable(msm_obj));
WARN_ON(obj->import_attach);
- mutex_lock_nested(&msm_obj->lock, subclass);
-
put_iova(obj);
- msm_gem_vunmap_locked(obj);
+ msm_gem_vunmap(obj);
put_pages(obj);
@@ -724,11 +721,9 @@ void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass)
invalidate_mapping_pages(file_inode(obj->filp)->i_mapping,
0, (loff_t)-1);
-
- msm_gem_unlock(obj);
}
-static void msm_gem_vunmap_locked(struct drm_gem_object *obj)
+void msm_gem_vunmap(struct drm_gem_object *obj)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
@@ -741,15 +736,6 @@ static void msm_gem_vunmap_locked(struct drm_gem_object *obj)
msm_obj->vaddr = NULL;
}
-void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass)
-{
- struct msm_gem_object *msm_obj = to_msm_bo(obj);
-
- mutex_lock_nested(&msm_obj->lock, subclass);
- msm_gem_vunmap_locked(obj);
- msm_gem_unlock(obj);
-}
-
/* must be called before _move_to_active().. */
int msm_gem_sync_object(struct drm_gem_object *obj,
struct msm_fence_context *fctx, bool exclusive)
@@ -986,7 +972,7 @@ static void free_object(struct msm_gem_object *msm_obj)
drm_prime_gem_destroy(obj, msm_obj->sgt);
} else {
- msm_gem_vunmap_locked(obj);
+ msm_gem_vunmap(obj);
put_pages(obj);
}
diff --git a/drivers/gpu/drm/msm/msm_gem.h b/drivers/gpu/drm/msm/msm_gem.h
index d55d5401a2d2..766ce278c74a 100644
--- a/drivers/gpu/drm/msm/msm_gem.h
+++ b/drivers/gpu/drm/msm/msm_gem.h
@@ -162,6 +162,13 @@ msm_gem_lock(struct drm_gem_object *obj)
mutex_lock(&msm_obj->lock);
}
+static inline bool __must_check
+msm_gem_trylock(struct drm_gem_object *obj)
+{
+ struct msm_gem_object *msm_obj = to_msm_bo(obj);
+ return mutex_trylock(&msm_obj->lock) == 1;
+}
+
static inline int
msm_gem_lock_interruptible(struct drm_gem_object *obj)
{
@@ -190,6 +197,7 @@ static inline bool is_active(struct msm_gem_object *msm_obj)
static inline bool is_purgeable(struct msm_gem_object *msm_obj)
{
+ WARN_ON(!msm_gem_is_locked(&msm_obj->base));
WARN_ON(!mutex_is_locked(&msm_obj->base.dev->struct_mutex));
return (msm_obj->madv == MSM_MADV_DONTNEED) && msm_obj->sgt &&
!msm_obj->base.dma_buf && !msm_obj->base.import_attach;
@@ -197,27 +205,12 @@ static inline bool is_purgeable(struct msm_gem_object *msm_obj)
static inline bool is_vunmapable(struct msm_gem_object *msm_obj)
{
+ WARN_ON(!msm_gem_is_locked(&msm_obj->base));
return (msm_obj->vmap_count == 0) && msm_obj->vaddr;
}
-/* The shrinker can be triggered while we hold objA->lock, and need
- * to grab objB->lock to purge it. Lockdep just sees these as a single
- * class of lock, so we use subclasses to teach it the difference.
- *
- * OBJ_LOCK_NORMAL is implicit (ie. normal mutex_lock() call), and
- * OBJ_LOCK_SHRINKER is used by shrinker.
- *
- * It is *essential* that we never go down paths that could trigger the
- * shrinker for a purgable object. This is ensured by checking that
- * msm_obj->madv == MSM_MADV_WILLNEED.
- */
-enum msm_gem_lock {
- OBJ_LOCK_NORMAL,
- OBJ_LOCK_SHRINKER,
-};
-
-void msm_gem_purge(struct drm_gem_object *obj, enum msm_gem_lock subclass);
-void msm_gem_vunmap(struct drm_gem_object *obj, enum msm_gem_lock subclass);
+void msm_gem_purge(struct drm_gem_object *obj);
+void msm_gem_vunmap(struct drm_gem_object *obj);
void msm_gem_free_work(struct work_struct *work);
/* Created per submit-ioctl, to track bo's and cmdstream bufs, etc,
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 482576d7a39a..2dc0ffa925b4 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -52,8 +52,11 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
return 0;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
+ if (!msm_gem_trylock(&msm_obj->base))
+ continue;
if (is_purgeable(msm_obj))
count += msm_obj->base.size >> PAGE_SHIFT;
+ msm_gem_unlock(&msm_obj->base);
}
if (unlock)
@@ -78,10 +81,13 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (freed >= sc->nr_to_scan)
break;
+ if (!msm_gem_trylock(&msm_obj->base))
+ continue;
if (is_purgeable(msm_obj)) {
- msm_gem_purge(&msm_obj->base, OBJ_LOCK_SHRINKER);
+ msm_gem_purge(&msm_obj->base);
freed += msm_obj->base.size >> PAGE_SHIFT;
}
+ msm_gem_unlock(&msm_obj->base);
}
if (unlock)
@@ -107,15 +113,20 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
return NOTIFY_DONE;
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
+ if (!msm_gem_trylock(&msm_obj->base))
+ continue;
if (is_vunmapable(msm_obj)) {
- msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER);
- /* since we don't know any better, lets bail after a few
- * and if necessary the shrinker will be invoked again.
- * Seems better than unmapping *everything*
- */
- if (++unmapped >= 15)
- break;
+ msm_gem_vunmap(&msm_obj->base);
+ unmapped++;
}
+ msm_gem_unlock(&msm_obj->base);
+
+ /* since we don't know any better, lets bail after a few
+ * and if necessary the shrinker will be invoked again.
+ * Seems better than unmapping *everything*
+ */
+ if (++unmapped >= 15)
+ break;
}
if (unlock)
--
2.26.2
next prev parent reply other threads:[~2020-10-23 16:50 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-23 16:51 [PATCH v4 00/23] drm/msm: de-struct_mutex-ification Rob Clark
2020-10-23 16:51 ` [PATCH v4 01/23] drm/msm: Fix a couple incorrect usages of get_vaddr_active() Rob Clark
2020-10-23 16:51 ` [PATCH v4 02/23] drm/msm/gem: Add obj->lock wrappers Rob Clark
2020-10-23 16:51 ` [PATCH v4 03/23] drm/msm/gem: Rename internal get_iova_locked helper Rob Clark
2020-10-23 16:51 ` [PATCH v4 04/23] drm/msm/gem: Move prototypes to msm_gem.h Rob Clark
2020-10-23 16:51 ` [PATCH v4 05/23] drm/msm/gem: Add some _locked() helpers Rob Clark
2020-10-23 16:51 ` Rob Clark [this message]
2020-10-23 16:51 ` [PATCH v4 07/23] drm/msm/submit: Move copy_from_user ahead of locking bos Rob Clark
2020-10-23 16:51 ` [PATCH v4 08/23] drm/msm: Do rpm get sooner in the submit path Rob Clark
2020-10-23 16:51 ` [PATCH v4 09/23] drm/msm/gem: Switch over to obj->resv for locking Rob Clark
2020-10-23 16:51 ` [PATCH v4 10/23] drm/msm: Use correct drm_gem_object_put() in fail case Rob Clark
2020-10-23 16:51 ` [PATCH v4 11/23] drm/msm: Drop chatty trace Rob Clark
2020-10-23 16:51 ` [PATCH v4 12/23] drm/msm: Move update_fences() Rob Clark
2020-10-23 16:51 ` [PATCH v4 13/23] drm/msm: Add priv->mm_lock to protect active/inactive lists Rob Clark
2020-10-23 16:51 ` [PATCH v4 14/23] drm/msm: Document and rename preempt_lock Rob Clark
2020-10-23 16:51 ` [PATCH v4 15/23] drm/msm: Protect ring->submits with it's own lock Rob Clark
2020-10-23 16:51 ` [PATCH v4 16/23] drm/msm: Refcount submits Rob Clark
2020-10-23 16:51 ` [PATCH v4 17/23] drm/msm: Remove obj->gpu Rob Clark
2020-10-23 16:51 ` [PATCH v4 18/23] drm/msm: Drop struct_mutex from the retire path Rob Clark
2020-10-23 16:51 ` [PATCH v4 19/23] drm/msm: Drop struct_mutex in free_object() path Rob Clark
2020-10-23 16:51 ` [PATCH v4 20/23] drm/msm: Remove msm_gem_free_work Rob Clark
2020-10-23 16:51 ` [PATCH v4 21/23] drm/msm: Drop struct_mutex in madvise path Rob Clark
2020-10-23 16:51 ` [PATCH v4 22/23] drm/msm: Drop struct_mutex in shrinker path Rob Clark
2020-10-23 16:51 ` [PATCH v4 23/23] drm/msm: Don't implicit-sync if only a single ring Rob Clark
2020-10-23 18:20 ` Lucas Stach
2020-10-24 3:49 ` Rob Clark
2020-10-26 9:34 ` Daniel Vetter
2020-10-29 16:14 ` Daniel Vetter
2020-10-29 16:59 ` Rob Clark
2020-10-29 18:22 ` Daniel Vetter
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