Re: [PERFORM] Linux mis-reporting memory

2007-10-02 Thread Decibel!
On Oct 2, 2007, at 1:37 PM, Adam Tauno Williams wrote: I'm leaning towards "top on linux == dumb". I disagree, it just isn't the appropriate tool for the job. What top tells you is lots of correct information, it just isn't the right information. If it is in fact including shared memory as

Re: [PERFORM] Linux mis-reporting memory

2007-10-02 Thread Adam Tauno Williams
> >> But then why is it not reporting that in the "Swap: used" > >> section ? It > >> only reports 42308k used swap. > > Hm, good point. > > The other possibility is that Postgres just hasn't even touched a > > large part > > of its shared buffers. > Sorry for the late reply... > No, this is on

Re: [PERFORM] Linux mis-reporting memory

2007-10-02 Thread Decibel!
On Sep 21, 2007, at 4:43 AM, Gregory Stark wrote: "Csaba Nagy" <[EMAIL PROTECTED]> writes: On Fri, 2007-09-21 at 09:03 +0100, Gregory Stark wrote: Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers Swap: 1951888k total,42308k used, 1909580k free, 30294300k cached

Re: [PERFORM] Linux mis-reporting memory

2007-10-02 Thread Scott Marlowe
On 10/2/07, Decibel! <[EMAIL PROTECTED]> wrote: > On Sep 21, 2007, at 4:43 AM, Gregory Stark wrote: > > "Csaba Nagy" <[EMAIL PROTECTED]> writes: > > > >> On Fri, 2007-09-21 at 09:03 +0100, Gregory Stark wrote: > > Mem: 32945280k total, 32871832k used,73448k free, > > 247432k buffers >

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Greg Smith
On Thu, 20 Sep 2007, Decibel! wrote: I'm finding this rather interesting report from top on a Debian box... how is it that linux thinks that 30G is cached? top on Linux gives weird results when faced with situations where there's shared memory involved. I look at /proc/meminfo and run ipcs w

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Csaba Nagy
On Fri, 2007-09-21 at 11:34 +0100, Heikki Linnakangas wrote: > Which version of Postgres is this? In 8.3, a scan like that really won't > suck it all into the shared buffer cache. For seq scans on tables larger > than shared_buffers/4, it switches to the bulk read strategy, using only > a few buff

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Simon Riggs
On Fri, 2007-09-21 at 12:08 +0200, Csaba Nagy wrote: > On Fri, 2007-09-21 at 10:43 +0100, Gregory Stark wrote: > > The other possibility is that Postgres just hasn't even touched a large part > > of its shared buffers. > > > > But then how do you explain the example I gave, with a 5.5GB table >

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Heikki Linnakangas
Csaba Nagy wrote: > On Fri, 2007-09-21 at 10:43 +0100, Gregory Stark wrote: >> The other possibility is that Postgres just hasn't even touched a large part >> of its shared buffers. > > But then how do you explain the example I gave, with a 5.5GB table > seq-scanned 3 times, shared buffers set to

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Csaba Nagy
On Fri, 2007-09-21 at 10:43 +0100, Gregory Stark wrote: > The other possibility is that Postgres just hasn't even touched a large part > of its shared buffers. > But then how do you explain the example I gave, with a 5.5GB table seq-scanned 3 times, shared buffers set to 12 GB, and top still sho

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Gregory Stark
"Csaba Nagy" <[EMAIL PROTECTED]> writes: > On Fri, 2007-09-21 at 09:03 +0100, Gregory Stark wrote: >> >> Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers >> >> Swap: 1951888k total,42308k used, 1909580k free, 30294300k cached >> > >> It seems to imply Linux is paging

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Dimitri Fontaine
Hi, Le Friday 21 September 2007 01:04:01 Decibel!, vous avez écrit : > I'm finding this rather interesting report from top on a Debian box... I've read from people in other free software development groups that top/ps memory usage outputs are not useful not trustable after all. A more usable (o

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Csaba Nagy
On Fri, 2007-09-21 at 09:03 +0100, Gregory Stark wrote: > >> Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers > >> Swap: 1951888k total,42308k used, 1909580k free, 30294300k cached > > > It seems to imply Linux is paging out sysV shared memory. In fact some of > Heikki

Re: [PERFORM] Linux mis-reporting memory

2007-09-21 Thread Gregory Stark
"Tom Lane" <[EMAIL PROTECTED]> writes: > Decibel! <[EMAIL PROTECTED]> writes: >> I'm finding this rather interesting report from top on a Debian box... > >> Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers >> Swap: 1951888k total,42308k used, 1909580k free, 30294300k

Re: [PERFORM] Linux mis-reporting memory

2007-09-20 Thread Adam Tauno Williams
> Sorry, I know this is probably more a linux question, but I'm guessing > that others have run into this... > I'm finding this rather interesting report from top on a Debian box... > Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers > Swap: 1951888k total,42308k used,

Re: [PERFORM] Linux mis-reporting memory

2007-09-20 Thread Tom Lane
Decibel! <[EMAIL PROTECTED]> writes: > I'm finding this rather interesting report from top on a Debian box... > Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers > Swap: 1951888k total,42308k used, 1909580k free, 30294300k cached > So how is it that linux thinks that

[PERFORM] Linux mis-reporting memory

2007-09-20 Thread Decibel!
Sorry, I know this is probably more a linux question, but I'm guessing that others have run into this... I'm finding this rather interesting report from top on a Debian box... Mem: 32945280k total, 32871832k used,73448k free, 247432k buffers Swap: 1951888k total,42308k used, 1909580k