Date: Wed, 23 Nov 2005 22:21:47 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Michael Conlen <m@obmail.net> Cc: freebsd-performance@freebsd.org Subject: Re: mmap() Message-ID: <20051123221952.D32130@fledge.watson.org> In-Reply-To: <6C48A943-1AB3-4DF4-B8CC-CD75B9F36E98@obmail.net> References: <6C48A943-1AB3-4DF4-B8CC-CD75B9F36E98@obmail.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, 23 Nov 2005, Michael Conlen wrote: > Sorry if this is the wrong place for this, but I haven't been getting > answers elsewhere. > > I'm trying to tune the system to allow very large mmap()'s in a single > process space, something on the order of 1.5 GB so I can pass very large > values for -Xms and -Xmx to java. I know I had been able to do this on > FreeBSD in the past but recent versions of either Java or FreeBSD aren't > playing nicely. currently.. BTW, you may find it useful to use procfs to inspect the address space layout of your process. You can d: mkdir /proc mount -t procfs proc /proc cd /proc/pid dd if=map of=/dev/stdout bs=20k This can help you look for fragmentation of process address space, among other things. Robert N M Watson > > I'm running > > FreeBSD host 6.0-RELEASE FreeBSD 6.0-RELEASE #0: Tue Nov 22 00:22:53 EST 2005 > root@host:/usr/obj/usr/src/sys/WWW i386 > > I've also tried the following under 5.4-p1... > > I try > > rc = mmap(0, (891*1024*1024 + 0), 0, MAP_ANON | MAP_PRIVATE, -1, 0); > > and it works but If I try > > rc = mmap(0, (892*1024*1024 + 0), 0, MAP_ANON | MAP_PRIVATE, -1, 0); > > it fails returning ENOMEM. > > limit returns > > cputime unlimited > filesize unlimited > datasize 2096128 kbytes > stacksize 1048576 kbytes > coredumpsize unlimited > memoryuse unlimited > vmemoryuse unlimited > descriptors 11095 > memorylocked unlimited > maxproc 5547 > sbsize unlimited > > If the program isn't doing anything else but that is there any reason I'm > getting limited in the amount of memory I can mmap() at about 892 MB? Ideally > I'd like to be able to mmap most of the 2 GB available to user procs. > > Oh, yes, there's plenty of free memory and swap. > > Thanks > > > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to > "freebsd-performance-unsubscribe@freebsd.org" >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20051123221952.D32130>