Re: [PERFORM] High Context-Switches on Linux 8.1.4 Server

2006-08-07 Thread Donald C. Sumbry ][
Tom Lane wrote: Sorry, I was unclear: it's the age of your oldest transaction that counts (measured by how many xacts started since it), not how many cycles it's consumed or not. With the 8.1 code it's possible for performance to degrade pretty badly once the age of your oldest transaction exc

Re: [PERFORM] High Context-Switches on Linux 8.1.4 Server

2006-08-07 Thread Donald C. Sumbry ][
Tom Lane wrote: We're seeing an average of 30,000 context-switches a sec. This problem was much worse w/8.0 and got bearable with 8.1 but slowly resurfaced. Is this from LWLock or spinlock contention? strace'ing a few backends could tell the difference: look to see how many select(0,...) yo

[PERFORM] High Context-Switches on Linux 8.1.4 Server

2006-08-07 Thread Donald C. Sumbry ][
Postgres 8.1.4 Slony 1.1.5 Linux manny 2.6.12-10-k7-smp #1 SMP Fri Apr 28 14:17:26 UTC 2006 i686 GNU/Linux We're seeing an average of 30,000 context-switches a sec. This problem was much worse w/8.0 and got bearable with 8.1 but slowly resurfaced. Any ideas? procs ---memory--