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From: palowoda@fiver (Bob Palowoda)
Newsgroups: comp.unix.internals
Subject: Re: What is the kernel doing?
Message-ID: <1990Nov16.082554.14085@fiver>
Date: 16 Nov 90 08:25:54 GMT
References: <1940@necisa.ho.necisa.oz>
Organization: Fiver Communications, Fremont, Ca
Lines: 27

From article <1940@necisa.ho.necisa.oz>, by boyd@necisa.ho.necisa.oz (Boyd Roberts):
> In article <1990Nov14.092733.456@fiver> palowoda@fiver.UUCP (Bob Palowoda) writes:
>> I'm curious, I was running umon386 and watching my system when there was
>>no activity. I notice that a rawch read causes a process switch. And in turn
>>it appears that the pwitch causes a iget, namei and dirblk. I assume the  
>>latter are disk access. Why does it do this?
>>
> 
> I think you've got it around the wrong way.  iget, namei and dirblk [sic]
> will cause process switches.

 Hmm, maybe. The only thing I noticed is when I hit the <space bar> I assumed
it caused a raw character read. And in turn a process context switch. The
inode functions <a guess here> is some sort of sync with the open stdio to
the cache. namei gets a inode from the current path and as Brian said
"don't know what this is doing exactly". Why it does 5 directory block 
access is still got me confused. For one character? I am confident it was
me hitting the space bar. I waited inbetween the cache to disk syncs to 
do it. Guess it's time to get the books out.

---Bob

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