Date: Thu, 15 Nov 2001 15:21:07 +0800 From: "David Xu" <davidx@viasoft.com.cn> To: "Matthew Dillon" <dillon@apollo.backplane.com> Cc: <freebsd-hackers@FreeBSD.ORG> Subject: Re: vm_map_protect() Message-ID: <001101c16da6$1834d980$ef01a8c0@davidwnt> References: <005a01c16d74$9e0c88a0$ef01a8c0@davidwnt> <200111150541.fAF5fbs18850@apollo.backplane.com>
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I like fast code. I want to avoid all object and entry
splitting and merging cost. besides, I think the code
is still very clear.
--
David Xu
----- Original Message -----
From: "Matthew Dillon" <dillon@apollo.backplane.com>
To: "David Xu" <davidx@viasoft.com.cn>
Cc: <freebsd-hackers@FreeBSD.ORG>
Sent: Thursday, November 15, 2001 1:41 PM
Subject: Re: vm_map_protect()
> :In FreeBSD 4.4-stable file /sys/vm/vm_map.c, function vm_map_protect()
> :will leave and have an entry splitted when first pass fails.
> :here is the patch to avoid such issue.
>
> Hmm... don't you want to vm_map_simplify_entry() at the end instead
> of vm_map_clip_start()?
>
> -Matt
> Matthew Dillon
> <dillon@backplane.com>
>
> :%diff -u vm_map.c.orig vm_map.c
> :--- vm_map.c.orig Thu Nov 15 08:27:19 2001
> :+++ vm_map.c Thu Nov 15 09:08:47 2001
> :@@ -999,13 +999,14 @@
> : {
> : vm_map_entry_t current;
> : vm_map_entry_t entry;
> :+ int clip_start = 0;
> :
> : vm_map_lock(map);
> :
> : VM_MAP_RANGE_CHECK(map, start, end);
> :
> : if (vm_map_lookup_entry(map, start, &entry)) {
> :- vm_map_clip_start(map, entry, start);
> :+ clip_start = 1;
> : } else {
> : entry = entry->next;
> : }
> :@@ -1026,6 +1027,8 @@
> : }
> : current = current->next;
> : }
> :+ if (clip_start)
> :+ vm_map_clip_start(map, entry, start);
> :
> : /*
> : * Go back and fix up protections. [Note that clipping is not
> :
> :--
> :David Xu
> :
> :
> :
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> :
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