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@xxxxxxxxxxx
Signed-off-by: Krzysztof Wilczyński <kw@xxxxxxxxx>
---
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
