Messages in this thread | | | Date | Mon, 7 Jan 2002 00:33:26 +1100 | From | Anton Blanchard <> | Subject | Re: [PATCH] Remove 8 bytes from struct page on 64bit archs |
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Hi Bill,
> Very true. I devised something to address this that appears to work on > multiple architectures already by folding ->zone into ->flags, which > could be useful. (Dave Jones recommended I just let arch maintainers > for things other than i386 mess with page_address() for other arches.) > OTOH, I'm more interested in getting it trimmed down than getting credit.
For archs that need ->zone, merging it with ->flags sounds like a great idea. Id like to cram something into ->flags on 64 bit archs since its only a long due to bitop constraints. I had thought of stuffing ->count in the high word but now Im just getting silly since all non atomic accesses to ->flags would then have to be word ones.
> My i386 version, which makes ->virtual conditional on CONFIG_HIGHMEM as > well, is at:
Id like to do redo some profiling, on ppc64 we had page_address() doing pointer arithmetic (instead of page->virtual) and the compiler created an awful sequence of instructions in the acenic interrupt handler. A zero copy TCP benchmark made it rather obvious.
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