Date: Thu, 7 Jan 1999 19:01:25 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Terry Lambert <tlambert@primenet.com> Cc: dyson@iquest.net, pfgiffun@bachue.usc.unal.edu.co, freebsd-hackers@FreeBSD.ORG Subject: Re: questions/problems with vm_fault() in Stable Message-ID: <199901080301.TAA36778@apollo.backplane.com>
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:> :cylinder groups to "grow" the MFS.
:>
:> No it doesn't. Explain to me how it aggravates the fragmentation
:> issue. Remember, we *don't* *care* how 'fragmented' the file data
:> is in MFS's device namespace. We just care how fragmented it is on
:> physical media - the swap backing store. The swapper automatically
:> defragments anything over a page in size.
:
:Kernel VM space fragmentation.
:
:Try to load a quiccam driver KLD that need to malloccontig.
What? That's your answer? That's a total bullshit answer and you
know it. You are blaming the fragmentation of *physical* memory on
subsystems that only use virtual mappings? Give me a break. MFS has
nothing to do with physical memory fragmentation... that's a function
of the fact that the VM page allocator doesn't give a damn about
physical memory fragmentation. It has NOTHING whatsoever to do with
MFS or any other VFS layer. Just doing a 'find /usr -type f | xargs md5'
will fragment physical memory as badly as MFS might.
If you need contiguous physical memory and can't preallocate it, then
go and write a defragmenter that reassigns pages. It would not be too
difficult - you just force the pager to cycle pages through the cache
and organize the free queue to repack them. Right now the free queue's
are a kind of LRUish design combined with the page-coloring code.
This has NOTHING to do with MFS. Nada. Zilch. None. Zero.
: Terry Lambert
: terry@lambert.org
:---
Matthew Dillon Engineering, HiWay Technologies, Inc. & BEST Internet
Communications & God knows what else.
<dillon@backplane.com> (Please include original email in any response)
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