Kris Kennaway <[EMAIL PROTECTED]> writes: > On Tue, Apr 10, 2007 at 02:46:56PM -0400, Tom Lane wrote: >> Oh, I'm sure the BSD kernel acts as you describe. But Mark's point is >> that Postgres never has more than one process waiting on any particular >> SysV semaphore, and so the problem doesn't really affect us.
> To be clear, some behaviour that postgresql does with sysv semaphores > causes wakeups of many processes at once. i.e. if you have 20 > clients, you will get up to 20 wakeups. I haven't studied the precise > cause of this, but it is empirically true. This is the scaling > problem I described, and it's what mux's patch addresses. [ shrug... ] To the extent that that happens, it's Postgres' own issue, and no amount of kernel rejiggering will change it. But I certainly have no objection to a patch that fixes the kernel behavior ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings