interesting and little-known feature of linux... looks like you can use anything for your system ram, and your system ram for anything :-) well, almost.
- t. -- cogito, ergo es. -----Forwarded Message----- > From: Winner of tha face compo <[EMAIL PROTECTED]> > To: MPlayer user's list. <[EMAIL PROTECTED]> > Subject: Re: [MPlayer-users] k62/500 / 256mb ram not enough for dvd-playback? > Date: 03 Apr 2003 09:16:03 +0200 > D Richard Felker III wrote: > > Actually, in your case, it may make it slower... Most Super7 > > motherboards (used with K6) have an idiotic design flaw where they > > cannot cache memory above 128 megs, so your system would probably get > > a lot faster if you dropped down at only 128 megs of ram instead of > > 256. > You've told this so many times that today I decided to investigate this. > I have a VIA MVP3 chipset with 192Mb RAM. > > A quick benchmark with different memory sizes (mem= option passed on boot) > showed that I got a whooping 18% performance increase with 128Mb RAM: > > 192Mb > BENCHMARKs: VC: 10.920s VO: 6.664s A: 0.000s Sys: 0.494s = 18.078s > 128Mb > BENCHMARKs: VC: 8.620s VO: 6.221s A: 0.000s Sys: 0.476s = 15.317s > > Using only 64Mb didn't make a difference (sigh). > > Then I RTFMed a bit, looking for a kernel patch for this functionality. > Fortunately, the kernel already contains a driver for this in its MTD > subsystem: slram.o > > With this driver it's possible to map any memory address to character and > block devices (compile mtdblock.o and/or mtdchar.o). > > /dev/mtd0: character special (90/0) > /dev/mtdblock0: block special (31/0) > > Setting it up couldn't be simpler: > modprobe slram map=DRAM,134217728,+0x04000000 (adds 64Mb RAM above 128Mb) > mkswap, swapon, and ready: 128Mb physical plus 64Mb swap, and 18% faster > MPlayer. > > > My other (diskless) box has only 32Mb RAM, so even MPlayer gets killed by > the kernel sometimes. But with slram.o, I could map 32Mb from the 64Mb memory > of the Geforce2 :) > > 01:00.0 VGA compatible controller: nVidia Corporation NV11 [GeForce2 MX] (rev b2) > (prog-if 00 [VGA]) > Subsystem: Asustek Computer, Inc.: Unknown device 403d > Flags: bus master, 66Mhz, medium devsel, latency 248, IRQ 11 > Memory at e4000000 (32-bit, non-prefetchable) [size=16M] > Memory at d8000000 (32-bit, prefetchable) [size=128M] > Expansion ROM at <unassigned> [disabled] [size=64K] > Capabilities: [60] Power Management version 2 > Capabilities: [44] AGP version 2.0 > > modprobe slram.o map=VRAM,0xda000000,+0x02000000 > > [EMAIL PROTECTED]:~# cat /proc/swaps > Filename Type Size Used Priority > /dev/mtdblock0 partition 32760 0 -2 > > (however, the binary-only nvidia driver doesn't honour the VideoRAM option > of XFree86 (!), so starting for example a 3D app makes XFree86 die.) -- To unsubscribe, send mail to [EMAIL PROTECTED] with the body "unsubscribe ilug-cal" and an empty subject line. FAQ: http://www.ilug-cal.org/node.php?id=3
