* [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch
@ 2016-09-09 7:42 kys
2016-09-14 14:46 ` Olaf Hering
0 siblings, 1 reply; 4+ messages in thread
From: kys @ 2016-09-09 7:42 UTC (permalink / raw)
To: gregkh, linux-kernel, devel, olaf, apw, vkuznets, jasowang,
leann.ogasawara, alexng
Cc: Vivek yadav, K. Y. Srinivasan
From: Vivek yadav <vyadav@microsoft.com>
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>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch
2016-09-09 7:42 [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch kys
@ 2016-09-14 14:46 ` Olaf Hering
0 siblings, 0 replies; 4+ messages in thread
From: Olaf Hering @ 2016-09-14 14:46 UTC (permalink / raw)
To: kys
Cc: gregkh, linux-kernel, devel, apw, vkuznets, jasowang,
leann.ogasawara, alexng, Vivek yadav
[-- Attachment #1: Type: text/plain, Size: 181 bytes --]
On Fri, Sep 09, kys@exchange.microsoft.com wrote:
> + * This check is safe since we are executing in the
> + * interrupt context and time synch messages arre always
Typo.
Olaf
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 163 bytes --]
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 0/2] Drivers: hv: vmbus: Use persistent IDs for vmbus device names
@ 2016-09-16 16:00 kys
2016-09-16 16:01 ` [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch kys
0 siblings, 1 reply; 4+ messages in thread
From: kys @ 2016-09-16 16:00 UTC (permalink / raw)
To: gregkh, linux-kernel, devel, olaf, apw, vkuznets, jasowang,
leann.ogasawara
Cc: K. Y. Srinivasan
From: K. Y. Srinivasan <kys@microsoft.com>
Use IDs that persist across reboots as vmbus device IDs.
Vitaly Kuznetsov (2):
Drivers: hv: make VMBus bus ids persistent
Drivers: hv: get rid of id in struct vmbus_channel
drivers/hv/channel_mgmt.c | 2 --
drivers/hv/vmbus_drv.c | 4 ++--
include/linux/hyperv.h | 3 ---
3 files changed, 2 insertions(+), 7 deletions(-)
--
1.7.4.1
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch
2016-09-16 16:00 [PATCH 0/2] Drivers: hv: vmbus: Use persistent IDs for vmbus device names kys
@ 2016-09-16 16:01 ` kys
2016-09-16 14:13 ` KY Srinivasan
0 siblings, 1 reply; 4+ messages in thread
From: kys @ 2016-09-16 16:01 UTC (permalink / raw)
To: gregkh, linux-kernel, devel, olaf, apw, vkuznets, jasowang,
leann.ogasawara
Cc: Vivek yadav, K. Y. Srinivasan
From: Vivek yadav <vyadav@microsoft.com>
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>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* RE: [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch
2016-09-16 16:01 ` [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch kys
@ 2016-09-16 14:13 ` KY Srinivasan
0 siblings, 0 replies; 4+ messages in thread
From: KY Srinivasan @ 2016-09-16 14:13 UTC (permalink / raw)
To: KY Srinivasan, gregkh@linuxfoundation.org,
linux-kernel@vger.kernel.org, devel@linuxdriverproject.org,
olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com,
jasowang@redhat.com, leann.ogasawara@canonical.com
Cc: Vivek Yadav
> -----Original Message-----
> From: kys@exchange.microsoft.com [mailto:kys@exchange.microsoft.com]
> Sent: Friday, September 16, 2016 9:31 PM
> To: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org;
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com;
> vkuznets@redhat.com; jasowang@redhat.com;
> leann.ogasawara@canonical.com
> Cc: Vivek Yadav <vyadav@microsoft.com>; KY Srinivasan
> <kys@microsoft.com>
> Subject: [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time
> synch
>
> From: Vivek yadav <vyadav@microsoft.com>
>
> 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>
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
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-09-16 14:29 UTC | newest]
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2016-09-09 7:42 [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch kys
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2016-09-16 16:00 [PATCH 0/2] Drivers: hv: vmbus: Use persistent IDs for vmbus device names kys
2016-09-16 16:01 ` [PATCH 1/1] Drivers: hv: hv_util: Avoid dynamic allocation in time synch kys
2016-09-16 14:13 ` KY Srinivasan
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