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@xxxxxxxxxxx>
>>
>> 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@xxxxxxxxxxx>
>> Signed-off-by: Nitesh Narayan Lal <nitesh@xxxxxxxxxx>
> Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>
>> ---
>> 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
>>
--
Nitesh
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