/* * Copyright (C) 2014 Red Hat * Author: Rob Clark * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. */ #ifndef DRM_MODESET_LOCK_H_ #define DRM_MODESET_LOCK_H_ #include struct drm_modeset_lock; /** * struct drm_modeset_acquire_ctx - locking context (see ww_acquire_ctx) * @ww_ctx: base acquire ctx * @contended: used internally for -EDEADLK handling * @locked: list of held locks * @trylock_only: trylock mode used in atomic contexts/panic notifiers * * Each thread competing for a set of locks must use one acquire * ctx. And if any lock fxn returns -EDEADLK, it must backoff and * retry. */ struct drm_modeset_acquire_ctx { struct ww_acquire_ctx ww_ctx; /* * Contended lock: if a lock is contended you should only call * drm_modeset_backoff() which drops locks and slow-locks the * contended lock. */ struct drm_modeset_lock *contended; /* * list of held locks (drm_modeset_lock) */ struct list_head locked; /* * Trylock mode, use only for panic handlers! */ bool trylock_only; }; /** * struct drm_modeset_lock - used for locking modeset resources. * @mutex: resource locking * @head: used to hold it's place on state->locked list when * part of an atomic update * * Used for locking CRTCs and other modeset resources. */ struct drm_modeset_lock { /* * modeset lock */ struct ww_mutex mutex; /* * Resources that are locked as part of an atomic update are added * to a list (so we know what to unlock at the end). */ struct list_head head; }; void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, uint32_t flags); void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx); void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx); void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx); int drm_modeset_backoff_interruptible(struct drm_modeset_acquire_ctx *ctx); void drm_modeset_lock_init(struct drm_modeset_lock *lock); /** * drm_modeset_lock_fini - cleanup lock * @lock: lock to cleanup */ static inline void drm_modeset_lock_fini(struct drm_modeset_lock *lock) { WARN_ON(!list_empty(&lock->head)); } /** * drm_modeset_is_locked - equivalent to mutex_is_locked() * @lock: lock to check */ static inline bool drm_modeset_is_locked(struct drm_modeset_lock *lock) { return ww_mutex_is_locked(&lock->mutex); } int drm_modeset_lock(struct drm_modeset_lock *lock, struct drm_modeset_acquire_ctx *ctx); int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock, struct drm_modeset_acquire_ctx *ctx); void drm_modeset_unlock(struct drm_modeset_lock *lock); struct drm_device; struct drm_crtc; struct drm_plane; void drm_modeset_lock_all(struct drm_device *dev); void drm_modeset_unlock_all(struct drm_device *dev); void drm_modeset_lock_crtc(struct drm_crtc *crtc, struct drm_plane *plane); void drm_modeset_unlock_crtc(struct drm_crtc *crtc); void drm_warn_on_modeset_not_all_locked(struct drm_device *dev); struct drm_modeset_acquire_ctx * drm_modeset_legacy_acquire_ctx(struct drm_crtc *crtc); int drm_modeset_lock_all_ctx(struct drm_device *dev, struct drm_modeset_acquire_ctx *ctx); #endif /* DRM_MODESET_LOCK_H_ */ .submit();'>
authorDexuan Cui <decui@microsoft.com>2017-01-28 11:46:02 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-31 10:59:48 +0100
commit433e19cf33d34bb6751c874a9c00980552fe508c (patch)
treece6547ef2987fbb289fa28f03536328a42781651 /include/rdma/ib_cache.h
parent191e885a2e130e639bb0c8ee350d7047294f2ce6 (diff)
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/rdma/ib_cache.h')