Bhuvan Kumar MITTAL wrote:
Hi Alan,

I believe that dma_alloc_coherent will mark the kernel buffer as uncached at alocation time. But that is not my intention. I have mapped some user space memory to the kernel buffer and I wish to ensure that the contents of both are coherent and correctly ordered.
In other words I wish to flush the contents of the kernel buffer to user space 
as soon as new data is available in my kernel buffer. How to do that? Will 
doing mysnc from the user space help?

msync is only for pagecache. If you modify user mapped RAM from the kernel, or 
wish
to read user modified RAM from the kernel, you should issue a flush_dcache_page 
after
and before, respectively. See Documentation/cachetlb.h.

Does that fix it? What are the details of your platform?

--
SUSE Labs, Novell Inc.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to