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Drivers: hv: hv_util: Avoid dynamic allocation in time synch 

Under stress, we have seen allocation failure in time synch code. Avoid
this dynamic allocation.

Signed-off-by: Vivek Yadav <vyadav@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vivek yadav 2016-09-09 00:42:30 -07:00 committed by Greg Kroah-Hartman
parent 54e9b09972
commit 3ba1eb17b6
1 changed files with 28 additions and 11 deletions
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39
drivers/hv/hv_util.c
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@ -64,9 +64,14 @@ static struct hv_util_service util_shutdown = {
.util_cb = shutdown_onchannelcallback,
};
static int hv_timesync_init(struct hv_util_service *srv);
static void hv_timesync_deinit(void);
static void timesync_onchannelcallback(void *context);
static struct hv_util_service util_timesynch = {
.util_cb = timesync_onchannelcallback,
.util_init = hv_timesync_init,
.util_deinit = hv_timesync_deinit,
};
static void heartbeat_onchannelcallback(void *context);
@ -201,7 +206,6 @@ static void hv_set_host_time(struct work_struct *work)
host_ts = ns_to_timespec(host_tns);
do_settimeofday(&host_ts);
kfree(wrk);
}
/*
@ -217,22 +221,24 @@ static void hv_set_host_time(struct work_struct *work)
* typically used as a hint to the guest. The guest is under no obligation
* to discipline the clock.
*/
static struct adj_time_work wrk;
static inline void adj_guesttime(u64 hosttime, u64 reftime, u8 flags)
{
struct adj_time_work *wrk;
wrk = kmalloc(sizeof(struct adj_time_work), GFP_ATOMIC);
if (wrk == NULL)
/*
* This check is safe since we are executing in the
* interrupt context and time synch messages arre always
* delivered on the same CPU.
*/
if (work_pending(&wrk.work))
return;
wrk->host_time = hosttime;
wrk->ref_time = reftime;
wrk->flags = flags;
wrk.host_time = hosttime;
wrk.ref_time = reftime;
wrk.flags = flags;
if ((flags & (ICTIMESYNCFLAG_SYNC | ICTIMESYNCFLAG_SAMPLE)) != 0) {
INIT_WORK(&wrk->work, hv_set_host_time);
schedule_work(&wrk->work);
} else
kfree(wrk);
schedule_work(&wrk.work);
}
}
/*
@ -457,6 +463,17 @@ static struct hv_driver util_drv = {
.remove = util_remove,
};
static int hv_timesync_init(struct hv_util_service *srv)
{
INIT_WORK(&wrk.work, hv_set_host_time);
return 0;
}
static void hv_timesync_deinit(void)
{
cancel_work_sync(&wrk.work);
}
static int __init init_hyperv_utils(void)
{
pr_info("Registering HyperV Utility Driver\n");