Re: Should I worry my server's memory?
On 2007-11-09 11:45, DarkPilgrim@xxxxxxxxx wrote:
Make my question simple: When I got 1500 users online, the first line
used was only 700MB. But after 3-day running, it's close to 2GB while
there are only 800 users online. The major difference is "cached" grew
dramatically.
According to what I have referred, "cached" is managed automatically
by the system but why it's not cleaned in case memory run out then
swap to degrade server's performance.
Of course the cache will grow when users access data, that is
the point, so they don't have to read from disk all the time.
When they start an application that require much memory, the kernel will
free some cache memory, and when the application exit, there will be
some unused memory that very soon will be used as cache again.
Since you never power down unused memory, why not use it as cache ?
/bb
.
Relevant Pages
- Re: Cached memory never gets released
... Stock linux 2.4.26 kernel. ... Due to flash bug 3M of memory gets lost due to font memory getting lost ... The output of "free" cache number steadily grows. ... longer to exhaust all of system memory with the cache. ...
(Linux-Kernel) - Re: Problem: Creating a raw binary string
... > While its true that a 64-bit cpu will move twice the data per instruction it ... > Memory bus width plays an important role here and unless it too is widened / ... You are forgetting the two levels of cache in the processor. ... The memory chips are addressed in Row col fashion. ...
(alt.comp.lang.borland-delphi) - Re: Is Greenspun enough?
... Most OSes memory map executables directly from the file system so code doesn't pollute the file cache or swap space. ...
(comp.lang.lisp) - Re: High-bandwidth computing interest group
... sequential access patterns, brute force - neither of us consider that interesting ... Perhaps we should lose the cache line orientation - transferring data bytes that aren't needed. ... Particularly if it has scatter/gather vector instructions like Larrabee, or if it is a CIMT coherent threaded architecture like the GPUs. ... As I have discussed in this newsgroup before, this allows us to have writeback caches where multiple processors can write to the same memory location simultaneously. ...
(comp.arch) - Re: Superstitious learning in Computer Architecture
... Without a LOT of logic or some other better approach, re-executing the instructions requires re-decoding and it ties up the cache memory bus transferring more data as instructions than the instructions are working on. ... The concept of cache is fundamentally flawed in that it STILL restricts access to one word per clock cycle, when a single modern ALU can easily use 5 plus whatever is eaten up with instruction accesses. ... The size of an optimizing compiler is proportional to the SQUARE of the size of the language times the SQUARE of the complexity of the machine - because all interactions must be considered. ...
(comp.arch.arithmetic) |
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