Re: Couldn't get a free page

Leonard N. Zubkoff (
Mon, 10 Mar 1997 09:23:49 -0800

Date: Mon, 10 Mar 1997 09:18:47 -0500 (EST)
From: "Richard B. Johnson" <>

Hello memory manager wizards........

What #define do I change and were to get some more pages for Disc I/O?
I can't write a large amount of data to a raw SCSI device for testing.
I use the BusLogic driver. It gets memory for "DMA" from the kernel.
It runs out and hangs.

The BusLogic driver itself should never hang waiting for DMA memory. The only
place it asks for memory after initialization is if it decides to expand the
number of CCBs. In that case, it calls with GFP_ATOMIC and should handle not
being able to create any.

I would think the DMA memory allocations are coming from the SCSI disk driver
itself (sd.c). I think there are some magic files in /proc that can reserve
more free pages, but I've never tried them.