From: Krzysztof Wilczyński <kw@linux.com>
Date: Sun, 15 Aug 2021 15:08:24 +0000 (+0000)
Subject: PCI: Add schedule point in proc_bus_pci_read()
X-Git-Tag: v5.15-rc1~61^2~19^2~3
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=a153e5e117ff562546ad3914045f2b5e1c302f88;p=linux-block.git

PCI: Add schedule point in proc_bus_pci_read()

PCI configuration space reads from /proc/bus/pci can often take several
milliseconds to complete.

Add a schedule point in proc_bus_pci_read() to reduce the maximum latency.

A similar change was made for sysfs by 2ce02a864ac1 ("PCI: Add schedule
point in pci_read_config()").

Link: https://lore.kernel.org/r/20200824052025.48362-1-benbjiang@tencent.com
Link: https://lore.kernel.org/r/20210815150824.96773-1-kw@linux.com
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---

diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 9bab07302bbf..535076eff5f6 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) {