[PATCH] kill lmb_add_io

Paul Mackerras paulus at samba.org
Wed Feb 4 13:22:27 EST 2004


Dave Hansen writes:

> This function seems to be dead code now.  I found it during a horribly
> confusing encounter with lmb.[ch] and CONFIG_MSCHUNKS.
>
> Does anyone know what an MSCHUNK is?  It seems like it simplifies some
> of the cases.  Does iSeries guarantee that the kernel's memory starts at
> 0 while pSeries doesn't?

A "Main Store chunk", I would think.

With iSeries, the hypervisor gives you memory in 256kB chunks (I
think), which can be scattered throughout physical memory.  The
CONFIG_MSCHUNKS stuff is a mapping layer that is there to give the
illusion to the main part of the kernel that physical memory starts at
0 and is contiguous, when in fact it's anything but.

A "LMB" is a "large memory block" AFAIK, and comes from the pSeries
side of things.

It does indeed seem that lmb_add_io is entirely unused.  Does anyone
have any good reason for keeping it?

Paul.

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