[lkml]   [2004]   [Jun]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: 32-bit dma allocations on 64-bit platforms

>>>>> On Wed, 23 Jun 2004 13:35:35 -0500, Terence Ripperda <> said:

Terence> based on each architecture's paging_init routines, the
Terence> zones look like this:

Terence> x86: ia64: x86_64:
Terence> ZONE_DMA: < 16M < ~4G < 16M
Terence> ZONE_NORMAL: 16M - ~1G > ~4G > 16M
Terence> ZONE_HIMEM: 1G+
Not that it matters here, but for correctness let me note that the
ia64 column is correct only for machines which don't have an I/O MMU.
With I/O MMU, ZONE_DMA will have the same coverage as ZONE_NORMAL with
a recent enough kernel (older kernels had a bug which limited ZONE_DMA
to < 4GB, but that was unintentional).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 14:04    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean