X-Original-To: pgsql-performance-postgresql.org@postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id 8E1079FA1A8 for ; Tue, 13 Jun 2006 23:04:39 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 63623-10 for ; Tue, 13 Jun 2006 23:04:34 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from sss.pgh.pa.us (sss.pgh.pa.us [66.207.139.130]) by postgresql.org (Postfix) with ESMTP id ECEC89FA38F for ; Tue, 13 Jun 2006 23:04:34 -0300 (ADT) Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1]) by sss.pgh.pa.us (8.13.6/8.13.6) with ESMTP id k5E24WGo018774; Tue, 13 Jun 2006 22:04:32 -0400 (EDT) To: mischa@ca.sophos.com cc: pgsql-performance@postgresql.org Subject: Re: Solaris shared_buffers anomaly? In-reply-to: <448F449A.6030900@ca.sophos.com> References: <1150151282.14661.42.camel@tigger> <20060613000441.GI8588@kenobi.snowman.net> <20060613200810.GZ34196@pervasive.com> <448F3A6E.6080908@ca.sophos.com> <11046.1150237327@sss.pgh.pa.us> <448F449A.6030900@ca.sophos.com> Comments: In-reply-to Mischa Sandberg message dated "Tue, 13 Jun 2006 16:04:58 -0700" Date: Tue, 13 Jun 2006 22:04:32 -0400 Message-ID: <18773.1150250672@sss.pgh.pa.us> From: Tom Lane X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200606/233 X-Sequence-Number: 19590 Mischa Sandberg writes: > Tom Lane wrote: >> Does Solaris have any call that allows locking a shmem segment in RAM? > Yes, mlock(). But want to understand what's going on before patching. Sure, but testing it with mlock() might help you understand what's going on, by eliminating one variable: we don't really know if the shmem is getting swapped, or something else. > For a dedicated DB server machine, Solaris has a feature: > create "intimate" shared memory with shmat(..., SHM_SHARE_MMU). > All backends share the same TLB entries (!). We use that already. (Hmm, might be interesting for you to turn it *off* and see if anything changes. See src/backend/port/sysv_shmem.c.) regards, tom lane