Messages in this thread | | | Subject | Re: A DMA patch for linux 2.2.9 | Date | Thu, 8 Jul 1999 14:51:40 -0700 (PDT) | From | (H.J. Lu) |
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> "H.J." > I also tested Jaroslav's patch and made the following comments: > - the hard limit needs at least a kernel load time > command line option (absolute or % of available > RAM were suggested by Dan Hollis) > - on a GFP_DMA fetch if the special DMA pool runs dry > then the main pool is not checked for candidates > - what about architectures that don't have this 16 MB > level (or something akin) limit?? > > Your patch addresses the first 2 points. Does it address > the 3rd?
No. We don't have any hardwares like that here. However, it is trivial to add a global variable, say
int dma_memory_limit = 1;
to indicate if the architecture has the DMA memory limit and each architecture can turn it off at the runt-time. We then can do
if (!dma_memory_limit) RMQUEUE_ANY(order); else { if (gfp_mask & __GFP_DMA) RMQUEUE_DMA(order); else { RMQUEUE_NODMA(order); RMQUEUE_ANY(order); } }
> > Doug Gilbert > > PS I don't think page_alloc.c changed between 2.2.9 and > 2.2.10-ac8. Haven't looked at "ac9" yet. So your patch > should work on more than just 2.2.9 . >
I also use it on 2.2.7.
-- H.J. Lu (hjl@gnu.org)
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