Serial stdio overwhelming interrupts

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi guys,

In my kvm machine, I use serial as its default stdio.
But when display a number of characters, e.g. cat a big ascii file, 
the serial always hangs as encount overwhelming interrupts, and then output a kernel log "serial8250: too much work for irq 42".

I found that the serial in qemu is primitive so that it generate a interrupt on every single character. 
This make it easier to reach the threshold of reporting "too much work".

I had to use the patch below to get this issue walked arroud.

Have you guys ever met the serial hanging problem before?

---
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index be95e55..af3e569 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -70,7 +70,7 @@ static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
 #define DEBUG_INTR(fmt...)	do { } while (0)
 #endif
 
-#define PASS_LIMIT	256
+#define PASS_LIMIT	65535
 
 /*
  * We default to IRQ0 for the "no irq" hack.   Some

Best Regards.
 
Yu
��.n��������+%������w��{.n�����o��^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�m


[Index of Archives]     [KVM Development]     [KVM ARM]     [KVM ia64]     [Linux Virtualization]     [Linux USB Devel]     [Linux Video]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Big List of Linux Books]

  Powered by Linux