From mboxrd@z Thu Jan  1 00:00:00 1970
To: 9fans@cse.psu.edu
Subject: Re: [9fans] Performance
From: forsyth@caldo.demon.co.uk
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Date: Wed,  9 May 2001 09:58:39 +0100
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>>Anyway, as fast as kernel compilation is, I do have some
>>questions about the performance.  I tried a few ways of
>>profiling the kernel during kernel compilation.  At first
>>I found that a lot of the kernel time was spent in halt()
>>so I changed HLT to NOP in l.s.  Now almost a third of the
>>time is apparently spent in runproc().

it's in runproc waiting for something to do (hence the HLT in later versions).
perhaps your action is i/o bound.