Re: [BUG] slab debug vs. L1 alignement

From: Manfred Spraul
Date: Fri Aug 15 2003 - 16:51:56 EST


Ben wrote:

Currently, when enabling slab debugging, we lose the property of
having the objects aligned on a cache line size.


Correct. Cache line alignment is advisory. Slab debugging is not the only case that violates the alignment, for example 32-byte allocations are not padded to the 128 byte cache line size of the Pentium 4 cpus. I really doubt we want that.

Have you looked at pci_pool_{create,alloc,free,destroy}? The functions were specifically written to provide aligned buffers for DMA operations. Perhaps SCSI should use them?

--
Manfred

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