* [PATCH] iommu/arm-smmu: fix "hang" when games exit @ 2019-09-07 17:50 Rob Clark 2019-09-10 15:01 ` Robin Murphy 0 siblings, 1 reply; 9+ messages in thread From: Rob Clark @ 2019-09-07 17:50 UTC (permalink / raw) To: iommu Cc: Rob Clark, Will Deacon, linux-arm-msm, Robin Murphy, open list, freedreno, moderated list:ARM SMMU DRIVERS From: Rob Clark <robdclark@chromium.org> When games, browser, or anything using a lot of GPU buffers exits, there can be many hundreds or thousands of buffers to unmap and free. If the GPU is otherwise suspended, this can cause arm-smmu to resume/suspend for each buffer, resulting 5-10 seconds worth of reprogramming the context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). To the user it would appear that the system is locked up. A simple solution is to use pm_runtime_put_autosuspend() instead, so we don't immediately suspend the SMMU device. Signed-off-by: Rob Clark <robdclark@chromium.org> --- Note: I've tied the autosuspend enable/delay to the consumer device, based on the reasoning that if the consumer device benefits from using an autosuspend delay, then it's corresponding SMMU probably does too. Maybe that is overkill and we should just unconditionally enable autosuspend. drivers/iommu/arm-smmu.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index c2733b447d9c..73a0dd53c8a3 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) { if (pm_runtime_enabled(smmu->dev)) - pm_runtime_put(smmu->dev); + pm_runtime_put_autosuspend(smmu->dev); } static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) @@ -1445,6 +1445,15 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) /* Looks ok, so add the device to the domain */ ret = arm_smmu_domain_add_master(smmu_domain, fwspec); +#ifdef CONFIG_PM + /* TODO maybe device_link_add() should do this for us? */ + if (dev->power.use_autosuspend) { + pm_runtime_set_autosuspend_delay(smmu->dev, + dev->power.autosuspend_delay); + pm_runtime_use_autosuspend(smmu->dev); + } +#endif + rpm_put: arm_smmu_rpm_put(smmu); return ret; -- 2.21.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH] iommu/arm-smmu: fix "hang" when games exit 2019-09-07 17:50 [PATCH] iommu/arm-smmu: fix "hang" when games exit Rob Clark @ 2019-09-10 15:01 ` Robin Murphy 2019-09-10 15:45 ` Rob Clark 2019-10-07 20:49 ` [PATCH v2] " Rob Clark 0 siblings, 2 replies; 9+ messages in thread From: Robin Murphy @ 2019-09-10 15:01 UTC (permalink / raw) To: Rob Clark, iommu Cc: Rob Clark, Will Deacon, linux-arm-msm, open list, freedreno, moderated list:ARM SMMU DRIVERS On 07/09/2019 18:50, Rob Clark wrote: > From: Rob Clark <robdclark@chromium.org> > > When games, browser, or anything using a lot of GPU buffers exits, there > can be many hundreds or thousands of buffers to unmap and free. If the > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > for each buffer, resulting 5-10 seconds worth of reprogramming the > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > To the user it would appear that the system is locked up. > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > don't immediately suspend the SMMU device. > > Signed-off-by: Rob Clark <robdclark@chromium.org> > --- > Note: I've tied the autosuspend enable/delay to the consumer device, > based on the reasoning that if the consumer device benefits from using > an autosuspend delay, then it's corresponding SMMU probably does too. > Maybe that is overkill and we should just unconditionally enable > autosuspend. I'm not sure there's really any reason to expect that a supplier's usage model when doing things for itself bears any relation to that of its consumer(s), so I'd certainly lean towards the "unconditional" argument myself. Of course ideally we'd skip resuming altogether in the map/unmap paths (since resume implies a full TLB reset anyway), but IIRC that approach started to get messy in the context of the initial RPM patchset. I'm planning to fiddle around a bit more to clean up the implementation of the new iommu_flush_ops stuff, so I've made a note to myself to revisit RPM to see if there's a sufficiently clean way to do better. In the meantime, though, I don't have any real objection to using some reasonable autosuspend delay on the principle that if we've been woken up to map/unmap one page, there's a high likelihood that more will follow in short order (and in the configuration slow-paths it won't have much impact either way). Robin. > drivers/iommu/arm-smmu.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index c2733b447d9c..73a0dd53c8a3 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > { > if (pm_runtime_enabled(smmu->dev)) > - pm_runtime_put(smmu->dev); > + pm_runtime_put_autosuspend(smmu->dev); > } > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > @@ -1445,6 +1445,15 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > /* Looks ok, so add the device to the domain */ > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); > > +#ifdef CONFIG_PM > + /* TODO maybe device_link_add() should do this for us? */ > + if (dev->power.use_autosuspend) { > + pm_runtime_set_autosuspend_delay(smmu->dev, > + dev->power.autosuspend_delay); > + pm_runtime_use_autosuspend(smmu->dev); > + } > +#endif > + > rpm_put: > arm_smmu_rpm_put(smmu); > return ret; > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH] iommu/arm-smmu: fix "hang" when games exit 2019-09-10 15:01 ` Robin Murphy @ 2019-09-10 15:45 ` Rob Clark 2019-10-07 20:49 ` [PATCH v2] " Rob Clark 1 sibling, 0 replies; 9+ messages in thread From: Rob Clark @ 2019-09-10 15:45 UTC (permalink / raw) To: Robin Murphy Cc: Rob Clark, Will Deacon, linux-arm-msm, open list, list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>, Joerg Roedel <joro@8bytes.org>, , freedreno, moderated list:ARM SMMU DRIVERS On Tue, Sep 10, 2019 at 8:01 AM Robin Murphy <robin.murphy@arm.com> wrote: > > On 07/09/2019 18:50, Rob Clark wrote: > > From: Rob Clark <robdclark@chromium.org> > > > > When games, browser, or anything using a lot of GPU buffers exits, there > > can be many hundreds or thousands of buffers to unmap and free. If the > > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > > for each buffer, resulting 5-10 seconds worth of reprogramming the > > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > > To the user it would appear that the system is locked up. > > > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > > don't immediately suspend the SMMU device. > > > > Signed-off-by: Rob Clark <robdclark@chromium.org> > > --- > > Note: I've tied the autosuspend enable/delay to the consumer device, > > based on the reasoning that if the consumer device benefits from using > > an autosuspend delay, then it's corresponding SMMU probably does too. > > Maybe that is overkill and we should just unconditionally enable > > autosuspend. > > I'm not sure there's really any reason to expect that a supplier's usage > model when doing things for itself bears any relation to that of its > consumer(s), so I'd certainly lean towards the "unconditional" argument > myself. Sounds good, I'll respin w/ unconditional autosuspend > Of course ideally we'd skip resuming altogether in the map/unmap paths > (since resume implies a full TLB reset anyway), but IIRC that approach > started to get messy in the context of the initial RPM patchset. I'm > planning to fiddle around a bit more to clean up the implementation of > the new iommu_flush_ops stuff, so I've made a note to myself to revisit > RPM to see if there's a sufficiently clean way to do better. In the > meantime, though, I don't have any real objection to using some > reasonable autosuspend delay on the principle that if we've been woken > up to map/unmap one page, there's a high likelihood that more will > follow in short order (and in the configuration slow-paths it won't have > much impact either way). It does sort of remind me about something I was chatting with Jordan the other day.. about how we could possibly skip the TLB inv for unmaps from non-current pagetables once we have per-context pagetables. The challenge is, since the GPU's command parser is the one switching pagetables, we don't have any race-free way to know which pagetables are current. But we do know which contexts have work queued up for the GPU, so we can know either that a given context definitely isn't current, or that it might be current. And in the "definitely not current" case we could skip TLB inv. BR, -R > > Robin. > > > drivers/iommu/arm-smmu.c | 11 ++++++++++- > > 1 file changed, 10 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > > index c2733b447d9c..73a0dd53c8a3 100644 > > --- a/drivers/iommu/arm-smmu.c > > +++ b/drivers/iommu/arm-smmu.c > > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > > { > > if (pm_runtime_enabled(smmu->dev)) > > - pm_runtime_put(smmu->dev); > > + pm_runtime_put_autosuspend(smmu->dev); > > } > > > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > > @@ -1445,6 +1445,15 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > > /* Looks ok, so add the device to the domain */ > > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); > > > > +#ifdef CONFIG_PM > > + /* TODO maybe device_link_add() should do this for us? */ > > + if (dev->power.use_autosuspend) { > > + pm_runtime_set_autosuspend_delay(smmu->dev, > > + dev->power.autosuspend_delay); > > + pm_runtime_use_autosuspend(smmu->dev); > > + } > > +#endif > > + > > rpm_put: > > arm_smmu_rpm_put(smmu); > > return ret; > > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-09-10 15:01 ` Robin Murphy 2019-09-10 15:45 ` Rob Clark @ 2019-10-07 20:49 ` Rob Clark 2019-10-09 10:10 ` Robin Murphy 2019-10-28 22:20 ` Will Deacon 1 sibling, 2 replies; 9+ messages in thread From: Rob Clark @ 2019-10-07 20:49 UTC (permalink / raw) To: iommu Cc: Rob Clark, Will Deacon, freedreno, open list, Robin Murphy, moderated list:ARM SMMU DRIVERS From: Rob Clark <robdclark@chromium.org> When games, browser, or anything using a lot of GPU buffers exits, there can be many hundreds or thousands of buffers to unmap and free. If the GPU is otherwise suspended, this can cause arm-smmu to resume/suspend for each buffer, resulting 5-10 seconds worth of reprogramming the context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). To the user it would appear that the system just locked up. A simple solution is to use pm_runtime_put_autosuspend() instead, so we don't immediately suspend the SMMU device. Signed-off-by: Rob Clark <robdclark@chromium.org> --- v1: original v2: unconditionally use autosuspend, rather than deciding based on what consumer does drivers/iommu/arm-smmu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 3f1d55fb43c4..b7b41f5001bc 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) { if (pm_runtime_enabled(smmu->dev)) - pm_runtime_put(smmu->dev); + pm_runtime_put_autosuspend(smmu->dev); } static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) @@ -1445,6 +1445,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) /* Looks ok, so add the device to the domain */ ret = arm_smmu_domain_add_master(smmu_domain, fwspec); + pm_runtime_set_autosuspend_delay(smmu->dev, 20); + pm_runtime_use_autosuspend(smmu->dev); + rpm_put: arm_smmu_rpm_put(smmu); return ret; -- 2.21.0 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-10-07 20:49 ` [PATCH v2] " Rob Clark @ 2019-10-09 10:10 ` Robin Murphy 2019-10-28 22:20 ` Will Deacon 1 sibling, 0 replies; 9+ messages in thread From: Robin Murphy @ 2019-10-09 10:10 UTC (permalink / raw) To: Rob Clark, iommu Cc: Rob Clark, freedreno, open list, Will Deacon, moderated list:ARM SMMU DRIVERS On 2019-10-07 9:49 pm, Rob Clark wrote: > From: Rob Clark <robdclark@chromium.org> > > When games, browser, or anything using a lot of GPU buffers exits, there > can be many hundreds or thousands of buffers to unmap and free. If the > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > for each buffer, resulting 5-10 seconds worth of reprogramming the > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > To the user it would appear that the system just locked up. > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > don't immediately suspend the SMMU device. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Rob Clark <robdclark@chromium.org> > --- > v1: original > v2: unconditionally use autosuspend, rather than deciding based on what > consumer does > > drivers/iommu/arm-smmu.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 3f1d55fb43c4..b7b41f5001bc 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > { > if (pm_runtime_enabled(smmu->dev)) > - pm_runtime_put(smmu->dev); > + pm_runtime_put_autosuspend(smmu->dev); > } > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > @@ -1445,6 +1445,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > /* Looks ok, so add the device to the domain */ > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); > > + pm_runtime_set_autosuspend_delay(smmu->dev, 20); > + pm_runtime_use_autosuspend(smmu->dev); > + > rpm_put: > arm_smmu_rpm_put(smmu); > return ret; > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-10-07 20:49 ` [PATCH v2] " Rob Clark 2019-10-09 10:10 ` Robin Murphy @ 2019-10-28 22:20 ` Will Deacon 2019-10-28 22:38 ` Rob Clark 1 sibling, 1 reply; 9+ messages in thread From: Will Deacon @ 2019-10-28 22:20 UTC (permalink / raw) To: Rob Clark Cc: Rob Clark, freedreno, open list, iommu, Robin Murphy, moderated list:ARM SMMU DRIVERS Hi Rob, On Mon, Oct 07, 2019 at 01:49:06PM -0700, Rob Clark wrote: > From: Rob Clark <robdclark@chromium.org> > > When games, browser, or anything using a lot of GPU buffers exits, there > can be many hundreds or thousands of buffers to unmap and free. If the > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > for each buffer, resulting 5-10 seconds worth of reprogramming the > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > To the user it would appear that the system just locked up. > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > don't immediately suspend the SMMU device. Please can you reword the subject to be a bit more useful? The commit message is great, but the subject is a bit like "fix bug in code" to me. > Signed-off-by: Rob Clark <robdclark@chromium.org> > --- > v1: original > v2: unconditionally use autosuspend, rather than deciding based on what > consumer does > > drivers/iommu/arm-smmu.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 3f1d55fb43c4..b7b41f5001bc 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > { > if (pm_runtime_enabled(smmu->dev)) > - pm_runtime_put(smmu->dev); > + pm_runtime_put_autosuspend(smmu->dev); > } > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > @@ -1445,6 +1445,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > /* Looks ok, so add the device to the domain */ > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); Please can you put a comment here explaining what this is doing? An abridged version of the commit message is fine. > + pm_runtime_set_autosuspend_delay(smmu->dev, 20); > + pm_runtime_use_autosuspend(smmu->dev); Cheers, Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-10-28 22:20 ` Will Deacon @ 2019-10-28 22:38 ` Rob Clark 2019-10-28 22:51 ` Robin Murphy 0 siblings, 1 reply; 9+ messages in thread From: Rob Clark @ 2019-10-28 22:38 UTC (permalink / raw) To: Will Deacon Cc: freedreno, iommu, open list, Robin Murphy, moderated list:ARM SMMU DRIVERS On Mon, Oct 28, 2019 at 3:20 PM Will Deacon <will@kernel.org> wrote: > > Hi Rob, > > On Mon, Oct 07, 2019 at 01:49:06PM -0700, Rob Clark wrote: > > From: Rob Clark <robdclark@chromium.org> > > > > When games, browser, or anything using a lot of GPU buffers exits, there > > can be many hundreds or thousands of buffers to unmap and free. If the > > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > > for each buffer, resulting 5-10 seconds worth of reprogramming the > > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > > To the user it would appear that the system just locked up. > > > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > > don't immediately suspend the SMMU device. > > Please can you reword the subject to be a bit more useful? The commit > message is great, but the subject is a bit like "fix bug in code" to me. yeah, not the best $subject, but I wasn't quite sure how to fit something better in a reasonable # of chars.. maybe something like: "iommu/arm-smmu: optimize unmap but avoiding toggling runpm state"? BR, -R > > > Signed-off-by: Rob Clark <robdclark@chromium.org> > > --- > > v1: original > > v2: unconditionally use autosuspend, rather than deciding based on what > > consumer does > > > > drivers/iommu/arm-smmu.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > > index 3f1d55fb43c4..b7b41f5001bc 100644 > > --- a/drivers/iommu/arm-smmu.c > > +++ b/drivers/iommu/arm-smmu.c > > @@ -289,7 +289,7 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) > > static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu) > > { > > if (pm_runtime_enabled(smmu->dev)) > > - pm_runtime_put(smmu->dev); > > + pm_runtime_put_autosuspend(smmu->dev); > > } > > > > static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom) > > @@ -1445,6 +1445,9 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > > /* Looks ok, so add the device to the domain */ > > ret = arm_smmu_domain_add_master(smmu_domain, fwspec); > > Please can you put a comment here explaining what this is doing? An abridged > version of the commit message is fine. > > > + pm_runtime_set_autosuspend_delay(smmu->dev, 20); > > + pm_runtime_use_autosuspend(smmu->dev); > > Cheers, > > Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-10-28 22:38 ` Rob Clark @ 2019-10-28 22:51 ` Robin Murphy 2019-10-29 11:15 ` Will Deacon 0 siblings, 1 reply; 9+ messages in thread From: Robin Murphy @ 2019-10-28 22:51 UTC (permalink / raw) To: Rob Clark, Will Deacon Cc: open list, iommu, freedreno, moderated list:ARM SMMU DRIVERS On 2019-10-28 10:38 pm, Rob Clark wrote: > On Mon, Oct 28, 2019 at 3:20 PM Will Deacon <will@kernel.org> wrote: >> >> Hi Rob, >> >> On Mon, Oct 07, 2019 at 01:49:06PM -0700, Rob Clark wrote: >>> From: Rob Clark <robdclark@chromium.org> >>> >>> When games, browser, or anything using a lot of GPU buffers exits, there >>> can be many hundreds or thousands of buffers to unmap and free. If the >>> GPU is otherwise suspended, this can cause arm-smmu to resume/suspend >>> for each buffer, resulting 5-10 seconds worth of reprogramming the >>> context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). >>> To the user it would appear that the system just locked up. >>> >>> A simple solution is to use pm_runtime_put_autosuspend() instead, so we >>> don't immediately suspend the SMMU device. >> >> Please can you reword the subject to be a bit more useful? The commit >> message is great, but the subject is a bit like "fix bug in code" to me. > > yeah, not the best $subject, but I wasn't quite sure how to fit > something better in a reasonable # of chars.. maybe something like: > "iommu/arm-smmu: optimize unmap but avoiding toggling runpm state"? FWIW, I'd be inclined to frame it as something like "avoid pathological RPM behaviour for unmaps". Robin. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v2] iommu/arm-smmu: fix "hang" when games exit 2019-10-28 22:51 ` Robin Murphy @ 2019-10-29 11:15 ` Will Deacon 0 siblings, 0 replies; 9+ messages in thread From: Will Deacon @ 2019-10-29 11:15 UTC (permalink / raw) To: Robin Murphy Cc: Rob Clark, iommu, open list, freedreno, moderated list:ARM SMMU DRIVERS On Mon, Oct 28, 2019 at 10:51:53PM +0000, Robin Murphy wrote: > On 2019-10-28 10:38 pm, Rob Clark wrote: > > On Mon, Oct 28, 2019 at 3:20 PM Will Deacon <will@kernel.org> wrote: > > > On Mon, Oct 07, 2019 at 01:49:06PM -0700, Rob Clark wrote: > > > > From: Rob Clark <robdclark@chromium.org> > > > > > > > > When games, browser, or anything using a lot of GPU buffers exits, there > > > > can be many hundreds or thousands of buffers to unmap and free. If the > > > > GPU is otherwise suspended, this can cause arm-smmu to resume/suspend > > > > for each buffer, resulting 5-10 seconds worth of reprogramming the > > > > context bank (arm_smmu_write_context_bank()/arm_smmu_write_s2cr()/etc). > > > > To the user it would appear that the system just locked up. > > > > > > > > A simple solution is to use pm_runtime_put_autosuspend() instead, so we > > > > don't immediately suspend the SMMU device. > > > > > > Please can you reword the subject to be a bit more useful? The commit > > > message is great, but the subject is a bit like "fix bug in code" to me. > > > > yeah, not the best $subject, but I wasn't quite sure how to fit > > something better in a reasonable # of chars.. maybe something like: > > "iommu/arm-smmu: optimize unmap but avoiding toggling runpm state"? > > FWIW, I'd be inclined to frame it as something like "avoid pathological RPM > behaviour for unmaps". LGTM! Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2019-10-29 11:16 UTC | newest] Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-09-07 17:50 [PATCH] iommu/arm-smmu: fix "hang" when games exit Rob Clark 2019-09-10 15:01 ` Robin Murphy 2019-09-10 15:45 ` Rob Clark 2019-10-07 20:49 ` [PATCH v2] " Rob Clark 2019-10-09 10:10 ` Robin Murphy 2019-10-28 22:20 ` Will Deacon 2019-10-28 22:38 ` Rob Clark 2019-10-28 22:51 ` Robin Murphy 2019-10-29 11:15 ` Will Deacon
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