/*
* Copyright © 2016 Collabora Ltd.
*
* 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_DEBUGFS_CRC_H__
#define __DRM_DEBUGFS_CRC_H__
#define DRM_MAX_CRC_NR 10
/**
* struct drm_crtc_crc_entry - entry describing a frame's content
* @has_frame_counter: whether the source was able to provide a frame number
* @frame: number of the frame this CRC is about, if @has_frame_counter is true
* @crc: array of values that characterize the frame
*/
struct drm_crtc_crc_entry {
bool has_frame_counter;
uint32_t frame;
uint32_t crcs[DRM_MAX_CRC_NR];
};
#define DRM_CRC_ENTRIES_NR 128
/**
* struct drm_crtc_crc - data supporting CRC capture on a given CRTC
* @lock: protects the fields in this struct
* @source: name of the currently configured source of CRCs
* @opened: whether userspace has opened the data file for reading
* @entries: array of entries, with size of %DRM_CRC_ENTRIES_NR
* @head: head of circular queue
* @tail: tail of circular queue
* @values_cnt: number of CRC values per entry, up to %DRM_MAX_CRC_NR
* @wq: workqueue used to synchronize reading and writing
*/
struct drm_crtc_crc {
spinlock_t lock;
const char *source;
bool opened;
struct drm_crtc_crc_entry *entries;
int head, tail;
size_t values_cnt;
wait_queue_head_t wq;
};
#if defined(CONFIG_DEBUG_FS)
int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
uint32_t frame, uint32_t *crcs);
#else
static inline int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
uint32_t frame, uint32_t *crcs)
{
return -EINVAL;
}
#endif /* defined(CONFIG_DEBUG_FS) */
#endif /* __DRM_DEBUGFS_CRC_H__ */
a href='/cgit.cgi/linux/net-next.git/log/net?id=2d47b8aac7ba697ffe05f839a3b4c3c628b4e430'>net/dccp/proto.c
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>