#ifndef __WATCHDOG_PRETIMEOUT_H
#define __WATCHDOG_PRETIMEOUT_H
#define WATCHDOG_GOV_NAME_MAXLEN 20
struct watchdog_device;
struct watchdog_governor {
const char name[WATCHDOG_GOV_NAME_MAXLEN];
void (*pretimeout)(struct watchdog_device *wdd);
};
#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV)
/* Interfaces to watchdog pretimeout governors */
int watchdog_register_governor(struct watchdog_governor *gov);
void watchdog_unregister_governor(struct watchdog_governor *gov);
/* Interfaces to watchdog_dev.c */
int watchdog_register_pretimeout(struct watchdog_device *wdd);
void watchdog_unregister_pretimeout(struct watchdog_device *wdd);
int watchdog_pretimeout_available_governors_get(char *buf);
int watchdog_pretimeout_governor_get(struct watchdog_device *wdd, char *buf);
int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
const char *buf);
#if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_NOOP)
#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "noop"
#elif IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_DEFAULT_GOV_PANIC)
#define WATCHDOG_PRETIMEOUT_DEFAULT_GOV "panic"
#endif
#else
static inline int watchdog_register_pretimeout(struct watchdog_device *wdd)
{
return 0;
}
static inline void watchdog_unregister_pretimeout(struct watchdog_device *wdd)
{
}
static inline int watchdog_pretimeout_available_governors_get(char *buf)
{
return -EINVAL;
}
static inline int watchdog_pretimeout_governor_get(struct watchdog_device *wdd,
char *buf)
{
return -EINVAL;
}
static inline int watchdog_pretimeout_governor_set(struct watchdog_device *wdd,
const char *buf)
{
return -EINVAL;
}
#endif
#endif
&id=433e19cf33d34bb6751c874a9c00980552fe508c'>refslogtreecommitdiff
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>