From: "Krzysztof Wilczyński" <kw@linux.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bin Lai <robinlai@tencent.com>,
Jiang Biao <benbjiang@tencent.com>,
linux-pci@vger.kernel.org
Subject: [PATCH] PCI: Allow scheduling to take place in proc_bus_pci_read()
Date: Sun, 15 Aug 2021 15:08:24 +0000 [thread overview]
Message-ID: <20210815150824.96773-1-kw@linux.com> (raw)
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(+)
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
next reply other threads:[~2021-08-15 15:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-15 15:08 Krzysztof Wilczyński [this message]
2021-08-20 21:23 ` [PATCH] PCI: Allow scheduling to take place in proc_bus_pci_read() Bjorn Helgaas
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