Unusually long delay in the kernel

[Alan Stern]

This code excerpt is taken from the start of the control thread for the 
usb-storage driver in 2.6.14-rc1:


static int usb_stor_control_thread(void * __us)
{
	struct us_data *us = (struct us_data *)__us;
	struct Scsi_Host *host = us_to_host(us);

printk(KERN_INFO "Before thread start\n");
	lock_kernel();

	/*
	 * This thread doesn't need any user-level access,
	 * so get rid of all our resources.
	 */
	daemonize("usb-storage");
	current->flags |= PF_NOFREEZE;
	unlock_kernel();
printk(KERN_INFO "After thread start\n");


The code between the two printk's takes a long time to run.  I don't have 
precise numbers, but it feels like more than 1 second.

(1) Can anyone explain why, or indicate how to speed it up?

(2) Are the {un}lock_kernel calls really needed?

Thanks,

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/