Messages in this thread | | | Date | Sat, 21 Oct 2000 11:03:13 -0400 (EDT) | From | Zhixu Liu <> | Subject | Re: about /proc/meminfo and mmap |
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On Sat, 21 Oct 2000, Cefiar wrote:
> At 08:24 PM 20/10/00 -0400, Zhixu Liu wrote: > >My PC have 128M RAM, but in /proc/meminfo, it display 122424K, not > >128*1024K = 131072K, what does this mean? > > Sounds like something is stealing your ram. > > Usual suspects are.. > > Shadow RAM is enabled. > - This steals a TINY (usually 64k for BIOS, and 32k each for each extra > memory address enabled) of ram. Nothing major though. > > Local memory accessing devices. > - Embedded video cards (and possibly embedded sound devices) on boards > using the Intel 815E chipset (and others) use local RAM for memory, instead > of their own special memory - to reduce cost. Apart from weird memory > sizes, this also can lead to latency and slow-down issues when accessing > the memory normally. Many of these machines have AGP slots, and almost > always have a PCI slot, so throwing in a cheap video (audio?) card can > remove such issues, and frees up that memory again. Maximum I've seen a > board allow for local video ram is 8 Meg, which is pretty much the amount > you are missing. The board in question was a Socket 7 board with embedded > video.
My PC is intel i810 chipset, so perhaps you are right. But now, question is if I want to reserve some RAM for program use, how can I do? Thanks for your help.
Zhixu
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