cache corruption patch
sam at freebsd.org
Tue Jun 2 17:17:10 UTC 2009
Mark Tinguely wrote:
> There has been several occurrences of memory corruption in ARM due to caching
> issues. A couple recent examples are problems with the SATA drive and new USB
> This patch tracks kernel mapped pages and detects when they are shared
> with existing user mapped pages and other kernel mapped pages. This patch
> has gone through some refinement in the last couple days with feed back
> from testers and is getting ready for being committed before the FreeBSD 8.0
> This patch should allow the removal of added cache invalidation commands to
> the dma.
> The patch is located at:
> For those interested, I can give a long explanation of the patch.
Have you measured the overhead of this additional state tracking
(time+space)? It appears to affect only dma buffers.
Not sure what "added cache invalidation commands" you're referring to,
can you explain? Perhaps you could just provide a separate patch that
shows which bus_dma ops you think can go away.
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