| Message ID | 20200610161226.424337-3-nitesh@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | Preventing job distribution to isolated CPUs | expand |
"git log --oneline drivers/pci/pci-driver.c" tells you that the subject should be something like: PCI: Restrict probe functions to housekeeping CPUs On Wed, Jun 10, 2020 at 12:12:25PM -0400, Nitesh Narayan Lal wrote: > From: Alex Belits <abelits@marvell.com> > > pci_call_probe() prevents the nesting of work_on_cpu() > for a scenario where a VF device is probed from work_on_cpu() > of the Physical device. > This patch replaces the cpumask used in pci_call_probe() > from all online CPUs to only housekeeping CPUs. This is to > ensure that there are no additional latency overheads > caused due to the pinning of jobs on isolated CPUs. s/Physical/PF/ (since you used "VF" earlier, this should match that) s/This patch replaces/Replace the/ Please rewrap this to fill a 75 column line (so it doesn't overflow 80 columns when "git log" adds 4 spaces). This should be two paragraphs; add a blank line between them. > Signed-off-by: Alex Belits <abelits@marvell.com> > Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> > --- > drivers/pci/pci-driver.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index da6510af1221..449466f71040 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -12,6 +12,7 @@ > #include <linux/string.h> > #include <linux/slab.h> > #include <linux/sched.h> > +#include <linux/sched/isolation.h> > #include <linux/cpu.h> > #include <linux/pm_runtime.h> > #include <linux/suspend.h> > @@ -333,6 +334,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > const struct pci_device_id *id) > { > int error, node, cpu; > + int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ; > struct drv_dev_and_id ddi = { drv, dev, id }; > > /* > @@ -353,7 +355,8 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > pci_physfn_is_probed(dev)) > cpu = nr_cpu_ids; > else > - cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); > + cpu = cpumask_any_and(cpumask_of_node(node), > + housekeeping_cpumask(hk_flags)); > > if (cpu < nr_cpu_ids) > error = work_on_cpu(cpu, local_pci_probe, &ddi); > -- > 2.18.4 >
On 6/16/20 4:05 PM, Bjorn Helgaas wrote: > "git log --oneline drivers/pci/pci-driver.c" tells you that the > subject should be something like: > > PCI: Restrict probe functions to housekeeping CPUs > > On Wed, Jun 10, 2020 at 12:12:25PM -0400, Nitesh Narayan Lal wrote: >> From: Alex Belits <abelits@marvell.com> >> >> pci_call_probe() prevents the nesting of work_on_cpu() >> for a scenario where a VF device is probed from work_on_cpu() >> of the Physical device. >> This patch replaces the cpumask used in pci_call_probe() >> from all online CPUs to only housekeeping CPUs. This is to >> ensure that there are no additional latency overheads >> caused due to the pinning of jobs on isolated CPUs. > s/Physical/PF/ (since you used "VF" earlier, this should match that) > > s/This patch replaces/Replace the/ > > Please rewrap this to fill a 75 column line (so it doesn't overflow 80 > columns when "git log" adds 4 spaces). > > This should be two paragraphs; add a blank line between them. Thanks for pointing these out. I will correct it in the next posting before that I will wait for any comments on other patches. > >> Signed-off-by: Alex Belits <abelits@marvell.com> >> Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> > Acked-by: Bjorn Helgaas <bhelgaas@google.com> > >> --- >> drivers/pci/pci-driver.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c >> index da6510af1221..449466f71040 100644 >> --- a/drivers/pci/pci-driver.c >> +++ b/drivers/pci/pci-driver.c >> @@ -12,6 +12,7 @@ >> #include <linux/string.h> >> #include <linux/slab.h> >> #include <linux/sched.h> >> +#include <linux/sched/isolation.h> >> #include <linux/cpu.h> >> #include <linux/pm_runtime.h> >> #include <linux/suspend.h> >> @@ -333,6 +334,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, >> const struct pci_device_id *id) >> { >> int error, node, cpu; >> + int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ; >> struct drv_dev_and_id ddi = { drv, dev, id }; >> >> /* >> @@ -353,7 +355,8 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, >> pci_physfn_is_probed(dev)) >> cpu = nr_cpu_ids; >> else >> - cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); >> + cpu = cpumask_any_and(cpumask_of_node(node), >> + housekeeping_cpumask(hk_flags)); >> >> if (cpu < nr_cpu_ids) >> error = work_on_cpu(cpu, local_pci_probe, &ddi); >> -- >> 2.18.4 >>
On Wed, Jun 10, 2020 at 12:12:25PM -0400, Nitesh Narayan Lal wrote: > From: Alex Belits <abelits@marvell.com> > > pci_call_probe() prevents the nesting of work_on_cpu() > for a scenario where a VF device is probed from work_on_cpu() > of the Physical device. > This patch replaces the cpumask used in pci_call_probe() > from all online CPUs to only housekeeping CPUs. This is to > ensure that there are no additional latency overheads > caused due to the pinning of jobs on isolated CPUs. > > Signed-off-by: Alex Belits <abelits@marvell.com> > Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com> > --- > drivers/pci/pci-driver.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > index da6510af1221..449466f71040 100644 > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -12,6 +12,7 @@ > #include <linux/string.h> > #include <linux/slab.h> > #include <linux/sched.h> > +#include <linux/sched/isolation.h> > #include <linux/cpu.h> > #include <linux/pm_runtime.h> > #include <linux/suspend.h> > @@ -333,6 +334,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > const struct pci_device_id *id) > { > int error, node, cpu; > + int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ; > struct drv_dev_and_id ddi = { drv, dev, id }; > > /* > @@ -353,7 +355,8 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, > pci_physfn_is_probed(dev)) > cpu = nr_cpu_ids; > else > - cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); > + cpu = cpumask_any_and(cpumask_of_node(node), > + housekeeping_cpumask(hk_flags)); Looks like cpumask_of_node() is based on online CPUs. So that all looks good. Thanks! Reviewed-by: Frederic Weisbecker <frederic@kernel.org> > > if (cpu < nr_cpu_ids) > error = work_on_cpu(cpu, local_pci_probe, &ddi); > -- > 2.18.4 >
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index da6510af1221..449466f71040 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -12,6 +12,7 @@ #include <linux/string.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/sched/isolation.h> #include <linux/cpu.h> #include <linux/pm_runtime.h> #include <linux/suspend.h> @@ -333,6 +334,7 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, const struct pci_device_id *id) { int error, node, cpu; + int hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ; struct drv_dev_and_id ddi = { drv, dev, id }; /* @@ -353,7 +355,8 @@ static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev, pci_physfn_is_probed(dev)) cpu = nr_cpu_ids; else - cpu = cpumask_any_and(cpumask_of_node(node), cpu_online_mask); + cpu = cpumask_any_and(cpumask_of_node(node), + housekeeping_cpumask(hk_flags)); if (cpu < nr_cpu_ids) error = work_on_cpu(cpu, local_pci_probe, &ddi);