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author | mpp <mpp@FreeBSD.org> | 1997-03-21 20:57:20 +0000 |
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committer | mpp <mpp@FreeBSD.org> | 1997-03-21 20:57:20 +0000 |
commit | 739a0bf67664914603367bd0db088b1edc7119dc (patch) | |
tree | 2c0eab9741d02b8e38426408ddffc7186c4f12b0 /lib/libc/sys/mmap.2 | |
parent | 8eaf2deaa2812ed3ea9fdea3f6b64f3d86d565f8 (diff) | |
download | FreeBSD-src-739a0bf67664914603367bd0db088b1edc7119dc.zip FreeBSD-src-739a0bf67664914603367bd0db088b1edc7119dc.tar.gz |
Use the .Tn macro for generic FreeBSD references. Other minor cleanup.
Diffstat (limited to 'lib/libc/sys/mmap.2')
-rw-r--r-- | lib/libc/sys/mmap.2 | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/lib/libc/sys/mmap.2 b/lib/libc/sys/mmap.2 index 1e8109d..c5d18e2 100644 --- a/lib/libc/sys/mmap.2 +++ b/lib/libc/sys/mmap.2 @@ -216,21 +216,26 @@ was specified and insufficient memory was available. .Xr munlock 2 , .Xr munmap 2 , .Xr getpagesize 3 - .Sh BUGS .Ar len is limited to 2GB. Mmapping slightly more than 2GB doesn't work, but it is possible to map a window of size (filesize % 2GB) for file sizes of slightly less than 2G, 4GB, 6GB and 8GB. - +.Pp The limit is imposed for a variety of reasons. Most of them have to do -with FreeBSD not wanting to use 64 bit offsets in the VM system due to -the extreme performance penalty. So FreeBSD uses 32bit page indexes and -this gives FreeBSD a maximum of 8TB filesizes. It's actually bugs in +with +.Tn FreeBSD +not wanting to use 64 bit offsets in the VM system due to +the extreme performance penalty. So +.Tn FreeBSD +uses 32bit page indexes and +this gives +.Tn FreeBSD +a maximum of 8TB filesizes. It's actually bugs in the filesystem code that causes the limit to be further restricted to 1TB (loss of precision when doing blockno calculations). - +.Pp Another reason for the 2GB limit is that filesystem metadata can reside at negative offsets. - +.Pp We currently can only deal with page aligned file offsets. |