diff options
Diffstat (limited to 'lib/libc/sys/mmap.2')
| -rw-r--r-- | lib/libc/sys/mmap.2 | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/lib/libc/sys/mmap.2 b/lib/libc/sys/mmap.2 index 185b7b8..cffccf8 100644 --- a/lib/libc/sys/mmap.2 +++ b/lib/libc/sys/mmap.2 @@ -133,9 +133,12 @@ Modifications are private. Modifications are shared. .It Dv MAP_STACK This option is only available if your system has been compiled with -VM_STACK defined when compiling the kernel. This is the default for -i386 only. Consider adding -DVM_STACK to COPTFLAGS in your /etc/make.conf -to enable this option for other architechures. MAP_STACK implies +VM_STACK defined when compiling the kernel. +This is the default for +i386 only. +Consider adding -DVM_STACK to COPTFLAGS in your /etc/make.conf +to enable this option for other architechures. +MAP_STACK implies MAP_ANON, and .Fa offset of 0. @@ -274,16 +277,19 @@ 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 +The limit is imposed for a variety of reasons. +Most of them have to do with .Tn FreeBSD not wanting to use 64 bit offsets in the VM system due to -the extreme performance penalty. So +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 +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 |
