> -----Original Message----- > From: kys@xxxxxxxxxxxxxxxxxxxxxx [mailto:kys@xxxxxxxxxxxxxxxxxxxxxx] > Sent: Friday, September 16, 2016 9:31 PM > To: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; > vkuznets@xxxxxxxxxx; jasowang@xxxxxxxxxx; > leann.ogasawara@xxxxxxxxxxxxx > Cc: Vivek Yadav <vyadav@xxxxxxxxxxxxx>; KY Srinivasan > <kys@xxxxxxxxxxxxx> > Subject: [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time > synch > > From: Vivek yadav <vyadav@xxxxxxxxxxxxx> > > Under stress, we have seen allocation failure in time synch code. Avoid > this dynamic allocation. > > Signed-off-by: Vivek Yadav <vyadav@xxxxxxxxxxxxx> > Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Greg, Please ignore this patch, It is already committed and got sent because of a glitch. Regards, K. Y > --- > 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 6286bdc..4aa3cb6 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"); > -- > 1.7.4.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
