From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <8a361ea78b8d25f710617b31c2eaf1ec@hamnavoe.com>
To: 9fans@9fans.net
From: Richard Miller <9fans@hamnavoe.com>
Date: Thu, 12 Nov 2009 21:19:16 +0000
In-Reply-To: <97f3a3e3c85b3c279d6121be7778ef43@coraid.com>
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Subject: Re: [9fans] mmu fix?
Topicbox-Message-UUID: 9a3e3f5a-ead5-11e9-9d60-3106f5b1d025

The two cases are:

/sys/src/9/pc/mmu.c:510,513
			if(didmmuinit)
				map = xspanalloc(BY2PG, BY2PG, 0);
			else
				map = rampage();

xspanalloc returns zeroed memory.  rampage is only called early
in startup, and returns virgin memory which in the olden days
would have been zeroed at boot time.  But nowadays:

/sys/src/9/pc/memory.c:443
			/* memset(va, 0, MB); so damn slow to memset all of memory */

So I think you want to clear the page only for the rampage case.