kernel/locking: Add context to ww_mutex_trylock()

i915 will soon gain an eviction path that trylock a whole lot of locks for eviction, getting dmesg failures like below: BUG: MAX_LOCK_DEPTH too low! turning off the locking correctness validator. depth: 48 max: 48! 48 locks held by i915_selftest/5776: #0: ffff888101a79240 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x88/0x160 freebsd#1: ffffc900009778c0 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_vma_pin.constprop.63+0x39/0x1b0 [i915] freebsd#2: ffff88800cf74de8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_vma_pin.constprop.63+0x5f/0x1b0 [i915] freebsd#3: ffff88810c7f9e38 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x1c4/0x9d0 [i915] freebsd#4: ffff88810bad5768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] freebsd#5: ffff88810bad60e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] ... freebsd#46: ffff88811964d768 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] freebsd#47: ffff88811964e0e8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: i915_gem_evict_something+0x110/0x860 [i915] INFO: lockdep is turned off. Fixing eviction to nest into ww_class_acquire is a high priority, but it requires a rework of the entire driver, which can only be done one step at a time. As an intermediate solution, add an acquire context to ww_mutex_trylock, which allows us to do proper nesting annotations on the trylocks, making the above lockdep splat disappear. This is also useful in regulator_lock_nested, which may avoid dropping regulator_nesting_mutex in the uncontended path, so use it there. TTM may be another user for this, where we could lock a buffer in a fastpath with list locks held, without dropping all locks we hold. [peterz: rework actual ww_mutex_trylock() implementations] Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YUBGPdDDjKlxAuXJ@hirez.programming.kicks-ass.net
dumbbell · Feb 13, 2023 · ca64d5d · ca64d5d
1 parent 52b60a6
commit ca64d5d
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Showing 9 changed files with 9 additions and 9 deletions.
diff --git a/amd/amdgpu/Makefile b/amd/amdgpu/Makefile
@@ -783,7 +783,7 @@ CFLAGS+= -I${SRCDIR}/pm/swsmu/smu13
 CFLAGS+= -I${DRM}/scheduler
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=amdgpu_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=amdgpu_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 SRCS+=	device_if.h vnode_if.h bus_if.h pci_if.h pci_iov_if.h device_if.h iicbus_if.h opt_drm.h \

diff --git a/dmabuf/Makefile b/dmabuf/Makefile
@@ -26,7 +26,7 @@ CFLAGS+= -I${.CURDIR:H}/linuxkpi/dummy/include # fallback to dummy
 CFLAGS+= -I${SYSDIR}/compat/linuxkpi/dummy/include
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= -DLINUXKPI_VERSION=51501
+CFLAGS+= -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 CWARNFLAGS.dma-buf.c+=	-Wno-pointer-arith

diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
@@ -280,7 +280,7 @@ static inline int modeset_lock(struct drm_modeset_lock *lock,
 	if (ctx->trylock_only) {
 		lockdep_assert_held(&ctx->ww_ctx);
 
-		if (!ww_mutex_trylock(&lock->mutex))
+		if (!ww_mutex_trylock(&lock->mutex, NULL))
 			return -EBUSY;
 		else
 			return 0;

diff --git a/drm/Makefile b/drm/Makefile
@@ -123,7 +123,7 @@ CFLAGS+= -I${.CURDIR:H}/include/uapi
 CFLAGS+= -I${SRCDIR:H}
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=drm_' -DDRM_SYSCTL_PARAM_PREFIX=_dri -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=drm_' -DDRM_SYSCTL_PARAM_PREFIX=_dri -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 SRCS+=	device_if.h \

diff --git a/i915/Makefile b/i915/Makefile
@@ -264,7 +264,7 @@ CFLAGS+= -I${.CURDIR:H}/include/uapi
 CFLAGS+= -I${SRCDIR:H:H} -I${SRCDIR} -I${SRCDIR}/display
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=i915_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=i915_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 SRCS	+=			\

diff --git a/linuxkpi/Makefile b/linuxkpi/Makefile
@@ -23,7 +23,7 @@ CFLAGS+= -I${.CURDIR}/dummy/include
 CFLAGS+= -I${.CURDIR}/gplv2/include
 CFLAGS+= -I${.CURDIR}/bsd/include
 CFLAGS+= -I${SYSDIR}/compat/linuxkpi/common/include
-CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"' -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"' -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 CFLAGS.gcc+= -Wno-cast-qual
 CFLAGS.linux_hdmi.c=	-Wno-cast-qual

diff --git a/linuxkpi/gplv2/include/linux/dma-resv.h b/linuxkpi/gplv2/include/linux/dma-resv.h
@@ -183,7 +183,7 @@ static inline int dma_resv_lock_slow_interruptible(struct dma_resv *obj,
  */
 static inline bool __must_check dma_resv_trylock(struct dma_resv *obj)
 {
-	return ww_mutex_trylock(&obj->lock);
+	return ww_mutex_trylock(&obj->lock, NULL);
 }
 
 /**

diff --git a/radeon/Makefile b/radeon/Makefile
@@ -133,7 +133,7 @@ CFLAGS+= -I${SRCDIR:H:H}
 CFLAGS+= -I${SRCDIR:H}/amd/include
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=radeon_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=radeon_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 CFLAGS.gcc+= -Wno-redundant-decls -Wno-cast-qual -Wno-unused-but-set-variable \

diff --git a/ttm/Makefile b/ttm/Makefile
@@ -38,7 +38,7 @@ CFLAGS+= -I${.CURDIR:H}/include/uapi
 CFLAGS+= -I${SRCDIR:H:H}
 
 CFLAGS+= '-DKBUILD_MODNAME="${KMOD}"'
-CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=ttm_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51501
+CFLAGS+= '-DLINUXKPI_PARAM_PREFIX=ttm_' -DDRM_SYSCTL_PARAM_PREFIX=_${KMOD} -DLINUXKPI_VERSION=51600
 CFLAGS+= ${KCONFIG:C/(.*)/-DCONFIG_\1/}
 
 SRCS+=	device_if.h \