On Fri, 25 May 2001, Linus Torvalds wrote:
> So I think I'll buy some experimentation. That HIGHMEM change is
> too ugly to live, though, I'd really like to hear more about why
> something that ugly is necessary.
If you mean the "GFP_BUFFER allocations should fail instead
of looping forever" thing, it is because:
1) GFP_BUFFER allocations are made in order to try to flush
(and free) pages and allocate highmem pages.
2) This is the page flushing equivalent of PF_MEMALLOC, in
the sense that we should not go and try to "recursively"
flush more random pages until we find one that succeeds
without an allocation; instead, we should just break the
loop and let the caller deal with it.
If you mean the change to nr_free_buffer_pages(), that one
is needed because that function should return what the name
implies ... returning "2 GB of memory available for dirty
buffers" makes for a completely filled up ZONE_NORMAL and
processes which never get throttled for writing (and instead,
end up looping for more memory and killing performance for
the rest of the system).
regards,
Rik
-- Linux MM bugzilla: http://linux-mm.org/bugzilla.shtmlVirtual memory is like a game you can't win; However, without VM there's truly nothing to lose...
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This archive was generated by hypermail 2b29 : Thu May 31 2001 - 21:00:26 EST