| Message ID | 20210815150824.96773-1-kw@linux.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Allow scheduling to take place in proc_bus_pci_read() | expand |
On Sun, Aug 15, 2021 at 03:08:24PM +0000, Krzysztof Wilczyński wrote: > PCI configuration space reads from the /proc/bus/pci for a particular > device, depending on the underlying hardware, can often take several > milliseconds to complete. > > Thus, add a schedule point in proc_bus_pci_read() to reduce the maximum > latency. > > A similar change has already been completed in the past for the sysfs > counterpart in the commit 2ce02a864ac1 ("PCI: Add schedule point in > pci_read_config()"). > > Link: https://lore.kernel.org/r/20200824052025.48362-1-benbjiang@tencent.com > Signed-off-by: Krzysztof Wilczyński <kw@linux.com> Applied to pci/misc for v5.15, thanks! I tweaked your subject line to match 2ce02a864ac1: PCI: Add schedule point in proc_bus_pci_read() > --- > drivers/pci/proc.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c > index d32fbfc93ea9..cb18f8a13ab6 100644 > --- a/drivers/pci/proc.c > +++ b/drivers/pci/proc.c > @@ -83,6 +83,7 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf, > buf += 4; > pos += 4; > cnt -= 4; > + cond_resched(); > } > > if (cnt >= 2) { > -- > 2.32.0 >
diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index d32fbfc93ea9..cb18f8a13ab6 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -83,6 +83,7 @@ static ssize_t proc_bus_pci_read(struct file *file, char __user *buf, buf += 4; pos += 4; cnt -= 4; + cond_resched(); } if (cnt >= 2) {
PCI configuration space reads from the /proc/bus/pci for a particular device, depending on the underlying hardware, can often take several milliseconds to complete. Thus, add a schedule point in proc_bus_pci_read() to reduce the maximum latency. A similar change has already been completed in the past for the sysfs counterpart in the commit 2ce02a864ac1 ("PCI: Add schedule point in pci_read_config()"). Link: https://lore.kernel.org/r/20200824052025.48362-1-benbjiang@tencent.com Signed-off-by: Krzysztof Wilczyński <kw@linux.com> --- drivers/pci/proc.c | 1 + 1 file changed, 1 insertion(+)