diff options
| author | Vivek yadav <vyadav@microsoft.com> | 2016-09-09 09:42:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-09 13:48:23 +0200 |
| commit | 3ba1eb17b633b419737b65429fa7124ce87c5efc (patch) | |
| tree | e17947cf668bcf02e12e42fa712d3bd4af6b19e1 /drivers/hv | |
| parent | fpga manager: Add hardware dependency to Zynq driver (diff) | |
| download | linux-3ba1eb17b633b419737b65429fa7124ce87c5efc.tar.xz linux-3ba1eb17b633b419737b65429fa7124ce87c5efc.zip | |
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>
Diffstat (limited to 'drivers/hv')
| -rw-r--r-- | drivers/hv/hv_util.c | 39 |
1 files changed, 28 insertions, 11 deletions
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 6286bdc02818..4aa3cb63fd41 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -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"); |