> Hongwei Li wrote: >>>On Thu, Feb 10, 2005 at 10:15:39AM +0100, DafyddHugh wrote: >>> > Hi, >>> > >>> > I am running Fedora Core 3 on a machine with 512Mb memory. >>> > >>> > There are 2 problems >>> > >>> > 1. When the physical memory is exhausted the system tries to use >>> swap, >>>the disk spins and the system becomes unusable. This is under >>>investigation, but any ideas would be appreciated. >>> > >>> > 2. More of an issue. Every few minutes (4 or 5) the available >>> physical >>>memory decreases by 64k, while the cache memory increases by 4k or 8k. >>>This is happening on a very "lean" machine (see simple ps post below). >>>No processes seem to be increasing memory at the same time. Usually the >>>machine also runs httpd, mysqld, popfile in addition to the posted ps. >>>It looks like a memory leak, but I can't find the offending process - >>>any ideas? >>> >>>Which kernel version are you running ? >>>What does the output of free, and slabtop look like ? >>> >>> Dave >> >> >> I have a similar question as 2 above. My system: 2.6.10-1.741_FC3 >> The free command displays the free physical memory decreasing >> continuesly >> every minute or so: >> >> # free >> total used free shared buffers >> cached >> Mem: 1035788 1017952 17836 0 296172 >> 81224 >> -/+ buffers/cache: 640556 395232 >> Swap: 1052216 8120 1044096 >> >> # free >> total used free shared buffers >> cached >> Mem: 1035788 1017980 17808 0 296228 >> 81244 >> -/+ buffers/cache: 640508 395280 >> Swap: 1052216 8120 1044096 >> >> # free >> total used free shared buffers >> cached >> Mem: 1035788 1018100 17688 0 296260 >> 81300 >> -/+ buffers/cache: 640540 395248 >> Swap: 1052216 8120 1044096 >> >> Is it normal? I don't know what will happen if the free memory goes to >> zero, but it seems that, in my system, it never goes to zero. At some >> point, it jumps up a little. Please note, my this system is a testing >> system, only 2 regular users were set up, and only 1 user is checking >> the >> testing emails (plus root's shell). It was just rebooted 2 days ago: >> >> # top >> top - 11:51:21 up 1 day, 21:36, 3 users, load average: 0.00, 0.00, >> 0.00 >> Tasks: 90 total, 1 running, 86 sleeping, 0 stopped, 3 zombie >> Cpu(s): 0.3% us, 0.0% sy, 0.0% ni, 99.3% id, 0.0% wa, 0.3% hi, >> 0.0% si >> Mem: 1035788k total, 1018564k used, 17224k free, 296420k buffers >> Swap: 1052216k total, 8120k used, 1044096k free, 81360k cached >> >> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND >> 10847 root 16 0 3632 948 756 R 0.7 0.1 0:00.07 top >> 3438 root 16 0 3940 580 492 S 0.3 0.1 0:17.43 nifd >> 3938 root 16 0 7756 4848 1612 S 0.3 0.5 1:11.28 hald >> 1 root 16 0 2756 560 480 S 0.0 0.1 0:00.82 init >> 2 root 34 19 0 0 0 S 0.0 0.0 0:00.08 ksoftirqd/0 >> ... >> >> Why does it take almost all of 1Gb physical ram? > > The kernel will attempt to use any available memory for buffering and > cacheing, as this makes things run faster. When applications need more > memory, buffer and cache space is released. So the figure you need to > look at in the "free" output is the one in the row marked "-/+ > buffers/cache:", which shows memory usage not in buffers and cache; that > represents how much memory you're "really" using. In your example above, > the last run of "free" actually showed more free memory than the first > one. > > Paul. > > -- > fedora-list mailing list > fedora-list@xxxxxxxxxx > To unsubscribe: http://www.redhat.com/mailman/listinfo/fedora-list > Thank you very much for help! Hongwei Li
