Re: [libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
On Tue, Aug 21, 2018 at 02:20:21PM +0200, Christian Ehrhardt wrote:
> On Tue, Aug 21, 2018 at 1:15 PM Daniel P. Berrangé
> wrote:
>
> > On Tue, Aug 14, 2018 at 11:27:33AM +0200, Christian Ehrhardt wrote:
> > > It was found that in cases with host devices virProcessKillPainfully
> > > might be able to send signal zero to the target PID for quite a while
> > > with the process already being gone from /proc/.
> > >
> > > That is due to cleanup and reset of devices which might include a
> > > secondary bus reset that on top of the actions taken has a 1s delay
> > > to let the bus settle. Due to that guests with plenty of Host devices
> > > could easily exceed the default timeouts.
> > >
> > > To solve that, this adds an extra delay of 2s per hostdev that is
> > associated
> > > to a VM.
> > >
> > > Signed-off-by: Christian Ehrhardt
> > > ---
> > > src/libvirt_private.syms | 1 +
> > > src/qemu/qemu_process.c | 5 +++--
> > > src/util/virprocess.c| 18 +++---
> > > src/util/virprocess.h| 1 +
> > > 4 files changed, 20 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> > > index ca4a192a4a..47ea35f864 100644
> > > --- a/src/libvirt_private.syms
> > > +++ b/src/libvirt_private.syms
> > > @@ -2605,6 +2605,7 @@ virProcessGetPids;
> > > virProcessGetStartTime;
> > > virProcessKill;
> > > virProcessKillPainfully;
> > > +virProcessKillPainfullyDelay;
> > > virProcessNamespaceAvailable;
> > > virProcessRunInMountNamespace;
> > > virProcessSchedPolicyTypeFromString;
> > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> > > index 02fdc55156..b7bf8813da 100644
> > > --- a/src/qemu/qemu_process.c
> > > +++ b/src/qemu/qemu_process.c
> > > @@ -6814,8 +6814,9 @@ qemuProcessKill(virDomainObjPtr vm, unsigned int
> > flags)
> > > return 0;
> > > }
> > >
> > > -ret = virProcessKillPainfully(vm->pid,
> > > - !!(flags &
> > VIR_QEMU_PROCESS_KILL_FORCE));
> > > +ret = virProcessKillPainfullyDelay(vm->pid,
> > > + !!(flags &
> > VIR_QEMU_PROCESS_KILL_FORCE),
> > > + vm->def->nhostdevs * 2);
> >
> > This API contract is a bit wierd. You've got an arbitray x2 multiplier
> > here...
> >
>
> Out of the discussion with Alex I derived that due to the 1 sec settling of
> the bus plus some extra work 2 seconds per device would be a good rule of
> thumb.
> The delay is meant to be in seconds and here it requests 2*nhostdevs to get
> the amount needed.
>
> And I'd not want to make the "unit" of the call "double-seconds" :-)
>
> Let me add a comment at this call to explain the reasoning on the
> multiplier here.
> > > -virProcessKillPainfully(pid_t pid, bool force)
> > > +virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int
> > extradelay)
> > > {
> > > size_t i;
> > > int ret = -1;
> > > +unsigned int delay = 75 + (extradelay*5);
> >
> > ...and it gets another x5 multiplier here.
> >
>
> That *5 is due to the internal unit it polls being 0.2 seconds.
> I think externally anything other than seconds (double-seconds,
> half-deca-seconds, ...) makes no sense.
Opps, yes, I mis-understood the behaviour of the code. A comment is fine
Regards,
Daniel
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Re: [libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
On Tue, Aug 21, 2018 at 1:15 PM Daniel P. Berrangé
wrote:
> On Tue, Aug 14, 2018 at 11:27:33AM +0200, Christian Ehrhardt wrote:
> > It was found that in cases with host devices virProcessKillPainfully
> > might be able to send signal zero to the target PID for quite a while
> > with the process already being gone from /proc/.
> >
> > That is due to cleanup and reset of devices which might include a
> > secondary bus reset that on top of the actions taken has a 1s delay
> > to let the bus settle. Due to that guests with plenty of Host devices
> > could easily exceed the default timeouts.
> >
> > To solve that, this adds an extra delay of 2s per hostdev that is
> associated
> > to a VM.
> >
> > Signed-off-by: Christian Ehrhardt
> > ---
> > src/libvirt_private.syms | 1 +
> > src/qemu/qemu_process.c | 5 +++--
> > src/util/virprocess.c| 18 +++---
> > src/util/virprocess.h| 1 +
> > 4 files changed, 20 insertions(+), 5 deletions(-)
> >
> > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> > index ca4a192a4a..47ea35f864 100644
> > --- a/src/libvirt_private.syms
> > +++ b/src/libvirt_private.syms
> > @@ -2605,6 +2605,7 @@ virProcessGetPids;
> > virProcessGetStartTime;
> > virProcessKill;
> > virProcessKillPainfully;
> > +virProcessKillPainfullyDelay;
> > virProcessNamespaceAvailable;
> > virProcessRunInMountNamespace;
> > virProcessSchedPolicyTypeFromString;
> > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> > index 02fdc55156..b7bf8813da 100644
> > --- a/src/qemu/qemu_process.c
> > +++ b/src/qemu/qemu_process.c
> > @@ -6814,8 +6814,9 @@ qemuProcessKill(virDomainObjPtr vm, unsigned int
> flags)
> > return 0;
> > }
> >
> > -ret = virProcessKillPainfully(vm->pid,
> > - !!(flags &
> VIR_QEMU_PROCESS_KILL_FORCE));
> > +ret = virProcessKillPainfullyDelay(vm->pid,
> > + !!(flags &
> VIR_QEMU_PROCESS_KILL_FORCE),
> > + vm->def->nhostdevs * 2);
>
> This API contract is a bit wierd. You've got an arbitray x2 multiplier
> here...
>
Out of the discussion with Alex I derived that due to the 1 sec settling of
the bus plus some extra work 2 seconds per device would be a good rule of
thumb.
The delay is meant to be in seconds and here it requests 2*nhostdevs to get
the amount needed.
And I'd not want to make the "unit" of the call "double-seconds" :-)
Let me add a comment at this call to explain the reasoning on the
multiplier here.
> diff --git a/src/util/virprocess.c b/src/util/virprocess.c
> > index ecea27a2d4..46360cc051 100644
> > --- a/src/util/virprocess.c
> > +++ b/src/util/virprocess.c
> > @@ -341,15 +341,19 @@ int virProcessKill(pid_t pid, int sig)
> > * Returns 0 if it was killed gracefully, 1 if it
> > * was killed forcibly, -1 if it is still alive,
> > * or another error occurred.
> > + *
> > + * Callers can proide an extra delay to wait longer
> > + * than the default.
>
> Mention that it is in "seconds"
>
Ack
> */
> > int
> > -virProcessKillPainfully(pid_t pid, bool force)
> > +virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int
> extradelay)
> > {
> > size_t i;
> > int ret = -1;
> > +unsigned int delay = 75 + (extradelay*5);
>
> ...and it gets another x5 multiplier here.
>
That *5 is due to the internal unit it polls being 0.2 seconds.
I think externally anything other than seconds (double-seconds,
half-deca-seconds, ...) makes no sense.
I'll call it "polldelay" instead to make it more clear that.
That uncommon *5 ratio was there before, just not as redable (it just
defined 75 in the loop header).
I'll add some text about it as well to be sure.
> Feels nicer to just have the caller provide a x10 multiplier and
> honour that directly
>
See above, the unit being seconds seems the most readable IMHO.
With the changes made I think it won't be as confusing.
> const char *signame = "TERM";
> >
> > -VIR_DEBUG("vpid=%lld force=%d", (long long)pid, force);
> > +VIR_DEBUG("vpid=%lld force=%d delay=%u", (long long)pid, force,
> pid);
>
> s/pid/extradelay/
>
Yes, that was mentioned by Bjoern and queued that way.
Also in the text the delay= should be extradelay= which is ready that way.
>
> > /* This loop sends SIGTERM, then waits a few iterations (10 seconds)
> > * to see if it dies. If the process still hasn't exited, and
> > @@ -357,9 +361,12 @@ virProcessKillPainfully(pid_t pid, bool force)
> > * wait up to 5 seconds more for the process to exit before
> > * returning.
> > *
> > + * An extra delay can be specified for cases that are expected to
> clean
> > + * up slower than usual.
> > + *
> > * Note that setting @force could result in dataloss for the
> process.
> > */
> > -for (i = 0; i < 75; i++) {
> > +for (i = 0; i < delay; i++) {
> > int signum;
> > if (i == 0) {
> >
Re: [libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
On Tue, Aug 14, 2018 at 11:27:33AM +0200, Christian Ehrhardt wrote:
> It was found that in cases with host devices virProcessKillPainfully
> might be able to send signal zero to the target PID for quite a while
> with the process already being gone from /proc/.
>
> That is due to cleanup and reset of devices which might include a
> secondary bus reset that on top of the actions taken has a 1s delay
> to let the bus settle. Due to that guests with plenty of Host devices
> could easily exceed the default timeouts.
>
> To solve that, this adds an extra delay of 2s per hostdev that is associated
> to a VM.
>
> Signed-off-by: Christian Ehrhardt
> ---
> src/libvirt_private.syms | 1 +
> src/qemu/qemu_process.c | 5 +++--
> src/util/virprocess.c| 18 +++---
> src/util/virprocess.h| 1 +
> 4 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index ca4a192a4a..47ea35f864 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -2605,6 +2605,7 @@ virProcessGetPids;
> virProcessGetStartTime;
> virProcessKill;
> virProcessKillPainfully;
> +virProcessKillPainfullyDelay;
> virProcessNamespaceAvailable;
> virProcessRunInMountNamespace;
> virProcessSchedPolicyTypeFromString;
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index 02fdc55156..b7bf8813da 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -6814,8 +6814,9 @@ qemuProcessKill(virDomainObjPtr vm, unsigned int flags)
> return 0;
> }
>
> -ret = virProcessKillPainfully(vm->pid,
> - !!(flags & VIR_QEMU_PROCESS_KILL_FORCE));
> +ret = virProcessKillPainfullyDelay(vm->pid,
> + !!(flags &
> VIR_QEMU_PROCESS_KILL_FORCE),
> + vm->def->nhostdevs * 2);
This API contract is a bit wierd. You've got an arbitray x2 multiplier
here...
> diff --git a/src/util/virprocess.c b/src/util/virprocess.c
> index ecea27a2d4..46360cc051 100644
> --- a/src/util/virprocess.c
> +++ b/src/util/virprocess.c
> @@ -341,15 +341,19 @@ int virProcessKill(pid_t pid, int sig)
> * Returns 0 if it was killed gracefully, 1 if it
> * was killed forcibly, -1 if it is still alive,
> * or another error occurred.
> + *
> + * Callers can proide an extra delay to wait longer
> + * than the default.
Mention that it is in "seconds"
> */
> int
> -virProcessKillPainfully(pid_t pid, bool force)
> +virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int extradelay)
> {
> size_t i;
> int ret = -1;
> +unsigned int delay = 75 + (extradelay*5);
...and it gets another x5 multiplier here.
Feels nicer to just have the caller provide a x10 multiplier and
honour that directly
> const char *signame = "TERM";
>
> -VIR_DEBUG("vpid=%lld force=%d", (long long)pid, force);
> +VIR_DEBUG("vpid=%lld force=%d delay=%u", (long long)pid, force, pid);
s/pid/extradelay/
>
> /* This loop sends SIGTERM, then waits a few iterations (10 seconds)
> * to see if it dies. If the process still hasn't exited, and
> @@ -357,9 +361,12 @@ virProcessKillPainfully(pid_t pid, bool force)
> * wait up to 5 seconds more for the process to exit before
> * returning.
> *
> + * An extra delay can be specified for cases that are expected to clean
> + * up slower than usual.
> + *
> * Note that setting @force could result in dataloss for the process.
> */
> -for (i = 0; i < 75; i++) {
> +for (i = 0; i < delay; i++) {
> int signum;
> if (i == 0) {
> signum = SIGTERM; /* kindly suggest it should exit */
> @@ -402,6 +409,11 @@ virProcessKillPainfully(pid_t pid, bool force)
> }
>
>
> +int virProcessKillPainfully(pid_t pid, bool force)
> +{
> +return virProcessKillPainfullyDelay(pid, force, 0);
> +}
> +
> #if HAVE_SCHED_GETAFFINITY
>
> int virProcessSetAffinity(pid_t pid, virBitmapPtr map)
> diff --git a/src/util/virprocess.h b/src/util/virprocess.h
> index 3c5a882772..b72603ca8e 100644
> --- a/src/util/virprocess.h
> +++ b/src/util/virprocess.h
> @@ -55,6 +55,7 @@ virProcessWait(pid_t pid, int *exitstatus, bool raw)
> int virProcessKill(pid_t pid, int sig);
>
> int virProcessKillPainfully(pid_t pid, bool force);
> +int virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int);
Missing parameter name here
Regards,
Daniel
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Re: [libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
On Tue, Aug 14, 2018 at 12:13 PM Bjoern Walk wrote:
> Christian Ehrhardt [2018-08-14,
> 11:27AM +0200]:
> > diff --git a/src/util/virprocess.c b/src/util/virprocess.c
> > index ecea27a2d4..46360cc051 100644
> > --- a/src/util/virprocess.c
> > +++ b/src/util/virprocess.c
> > @@ -341,15 +341,19 @@ int virProcessKill(pid_t pid, int sig)
> > * Returns 0 if it was killed gracefully, 1 if it
> > * was killed forcibly, -1 if it is still alive,
> > * or another error occurred.
> > + *
> > + * Callers can proide an extra delay to wait longer
> > + * than the default.
> > */
> > int
> > -virProcessKillPainfully(pid_t pid, bool force)
> > +virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int
> extradelay)
> > {
> > size_t i;
> > int ret = -1;
> > +unsigned int delay = 75 + (extradelay*5);
> > const char *signame = "TERM";
> >
> > -VIR_DEBUG("vpid=%lld force=%d", (long long)pid, force);
> > +VIR_DEBUG("vpid=%lld force=%d delay=%u", (long long)pid, force,
> pid);
>^
> This probably should be delay, right?
>
Absolutely correct, bad old copy-pasta from the beginning of this change.
Thanks for spotting it.
Example is with 12 Devices passed through and force, which means with both
patches applied:
- raise base value to wait after kill by 30 seconds (force is set) - second
patch
- request 12*2 seconds extra for the devices - this patch
That should be 200+(12*2*5)=320 and that matches what I see int he log:
2018-08-16 13:04:51.999+: 61243: debug :
virProcessKillPainfullyDelay:359 : vpid=60939 force=1 delay=320
I'm not pushing a V2 just for the change, but I have it queued with the
fixed variable.
Any other feedback on this or the sibling patch?
Especially since those aren't my usual apparmor changes I'd really want
some more reviews/acks before considering a push.
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Re: [libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
Christian Ehrhardt [2018-08-14, 11:27AM
+0200]:
> diff --git a/src/util/virprocess.c b/src/util/virprocess.c
> index ecea27a2d4..46360cc051 100644
> --- a/src/util/virprocess.c
> +++ b/src/util/virprocess.c
> @@ -341,15 +341,19 @@ int virProcessKill(pid_t pid, int sig)
> * Returns 0 if it was killed gracefully, 1 if it
> * was killed forcibly, -1 if it is still alive,
> * or another error occurred.
> + *
> + * Callers can proide an extra delay to wait longer
> + * than the default.
> */
> int
> -virProcessKillPainfully(pid_t pid, bool force)
> +virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int extradelay)
> {
> size_t i;
> int ret = -1;
> +unsigned int delay = 75 + (extradelay*5);
> const char *signame = "TERM";
>
> -VIR_DEBUG("vpid=%lld force=%d", (long long)pid, force);
> +VIR_DEBUG("vpid=%lld force=%d delay=%u", (long long)pid, force, pid);
^
This probably should be delay, right?
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[libvirt] [PATCH v3 1/2] process: wait longer on kill per assigned Hostdev
It was found that in cases with host devices virProcessKillPainfully
might be able to send signal zero to the target PID for quite a while
with the process already being gone from /proc/.
That is due to cleanup and reset of devices which might include a
secondary bus reset that on top of the actions taken has a 1s delay
to let the bus settle. Due to that guests with plenty of Host devices
could easily exceed the default timeouts.
To solve that, this adds an extra delay of 2s per hostdev that is associated
to a VM.
Signed-off-by: Christian Ehrhardt
---
src/libvirt_private.syms | 1 +
src/qemu/qemu_process.c | 5 +++--
src/util/virprocess.c| 18 +++---
src/util/virprocess.h| 1 +
4 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index ca4a192a4a..47ea35f864 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2605,6 +2605,7 @@ virProcessGetPids;
virProcessGetStartTime;
virProcessKill;
virProcessKillPainfully;
+virProcessKillPainfullyDelay;
virProcessNamespaceAvailable;
virProcessRunInMountNamespace;
virProcessSchedPolicyTypeFromString;
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 02fdc55156..b7bf8813da 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6814,8 +6814,9 @@ qemuProcessKill(virDomainObjPtr vm, unsigned int flags)
return 0;
}
-ret = virProcessKillPainfully(vm->pid,
- !!(flags & VIR_QEMU_PROCESS_KILL_FORCE));
+ret = virProcessKillPainfullyDelay(vm->pid,
+ !!(flags & VIR_QEMU_PROCESS_KILL_FORCE),
+ vm->def->nhostdevs * 2);
return ret;
}
diff --git a/src/util/virprocess.c b/src/util/virprocess.c
index ecea27a2d4..46360cc051 100644
--- a/src/util/virprocess.c
+++ b/src/util/virprocess.c
@@ -341,15 +341,19 @@ int virProcessKill(pid_t pid, int sig)
* Returns 0 if it was killed gracefully, 1 if it
* was killed forcibly, -1 if it is still alive,
* or another error occurred.
+ *
+ * Callers can proide an extra delay to wait longer
+ * than the default.
*/
int
-virProcessKillPainfully(pid_t pid, bool force)
+virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int extradelay)
{
size_t i;
int ret = -1;
+unsigned int delay = 75 + (extradelay*5);
const char *signame = "TERM";
-VIR_DEBUG("vpid=%lld force=%d", (long long)pid, force);
+VIR_DEBUG("vpid=%lld force=%d delay=%u", (long long)pid, force, pid);
/* This loop sends SIGTERM, then waits a few iterations (10 seconds)
* to see if it dies. If the process still hasn't exited, and
@@ -357,9 +361,12 @@ virProcessKillPainfully(pid_t pid, bool force)
* wait up to 5 seconds more for the process to exit before
* returning.
*
+ * An extra delay can be specified for cases that are expected to clean
+ * up slower than usual.
+ *
* Note that setting @force could result in dataloss for the process.
*/
-for (i = 0; i < 75; i++) {
+for (i = 0; i < delay; i++) {
int signum;
if (i == 0) {
signum = SIGTERM; /* kindly suggest it should exit */
@@ -402,6 +409,11 @@ virProcessKillPainfully(pid_t pid, bool force)
}
+int virProcessKillPainfully(pid_t pid, bool force)
+{
+return virProcessKillPainfullyDelay(pid, force, 0);
+}
+
#if HAVE_SCHED_GETAFFINITY
int virProcessSetAffinity(pid_t pid, virBitmapPtr map)
diff --git a/src/util/virprocess.h b/src/util/virprocess.h
index 3c5a882772..b72603ca8e 100644
--- a/src/util/virprocess.h
+++ b/src/util/virprocess.h
@@ -55,6 +55,7 @@ virProcessWait(pid_t pid, int *exitstatus, bool raw)
int virProcessKill(pid_t pid, int sig);
int virProcessKillPainfully(pid_t pid, bool force);
+int virProcessKillPainfullyDelay(pid_t pid, bool force, unsigned int);
int virProcessSetAffinity(pid_t pid, virBitmapPtr map);
--
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