From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from digeo-nav01.digeo.com (digeo-nav01.digeo.com [192.168.1.233]) by packet.digeo.com (8.9.3+Sun/8.9.3) with SMTP id QAA09593 for ; Sat, 21 Sep 2002 16:53:20 -0700 (PDT) Message-ID: <3D8D066F.1B45E3EA@digeo.com> Date: Sat, 21 Sep 2002 16:53:19 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: overcommit stuff References: <3D8D0046.EF119E03@digeo.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Alan Cox , "linux-mm@kvack.org" List-ID: Hugh Dickins wrote: > > On Sat, 21 Sep 2002, Andrew Morton wrote: > > Alan, > > > > running 10,000 tiobench threads I'm showing 23 gigs of > > `Commited_AS'. Is this right? Those pages are shared, > > and if they're not PROT_WRITEable then there's no way in > > which they can become unshared? Seems to be excessively > > pessimistic? > > > > Or is 2.5 not up to date? > > I don't think Alan can be held responsible for errors in the > overcommit stuff rml ported to 2.5 and I then added fixes to. Well I'm not saying it's an error. It may be by design. > I believe it is up to date in 2.5. OK. > Committed_AS certainly errs on the pessimistic side, that's > what it's about. How much swap do you have i.e. is 23GB > committed impossible, or just surprising to you? Does the > number go back to what it started off from when you kill > off the tests? How are "those pages" allocated e.g. what > mmap args? I have 7G physical, 4G swap. "those pages" were just used by some scruffy perl script running `./tiotest &' ten thousand times. I assume it's shared executable text. It seems very unlikely (impossible?) that those pages will ever become unshared. Are they returned when the threads are killed? Dunno - the machine got a vists from the NMI watchdog in the scheduler somewhere before I could tell. Retesting... Here's what I had when it died: MemTotal: 7249608 kB MemFree: 7180 kB MemShared: 0 kB Buffers: 29040 kB Cached: 6879180 kB SwapCached: 51216 kB Active: 22672 kB Inactive: 6950548 kB HighTotal: 6422528 kB HighFree: 2980 kB LowTotal: 827080 kB LowFree: 4200 kB SwapTotal: 3951844 kB SwapFree: 3829764 kB Dirty: 658468 kB Writeback: 10640 kB Mapped: 57228 kB Slab: 83188 kB Committed_AS: 28417140 kB PageTables: 58152 kB ReverseMaps: 28455 nr_dirty 165433 nr_writeback 2663 nr_pagecache 1739859 nr_page_table_pages 14538 nr_reverse_maps 28455 nr_mapped 14307 nr_slab 20802 pswpin 45 pswpout 30532 pgalloc 6671454 pgfree 6673245 pgactivate 74265 pgdeactivate 68457 pgfault 1261681 pgmajfault 714 pgscan 4640872 pgrefill 100136 pgsteal 4329474 kswapd_steal 1413013 pageoutrun 90269 allocstall 90269 buffer_head: 25669KB 30953KB 82.92 task_struct: 14648KB 15218KB 96.25 radix_tree_node: 12337KB 12354KB 99.85 ext2_inode_cache: 4058KB 4058KB 100.0 vm_area_struct: 2463KB 2475KB 99.52 size-512: 1428KB 1428KB 100.0 filp: 1301KB 1301KB 100.0 dentry_cache: 1290KB 1290KB 100.0 biovec-BIO_MAX_PAGES: 780KB 780KB 100.0 names_cache: 744KB 748KB 99.46 biovec-64: 677KB 723KB 93.57 blkdev_requests: 625KB 633KB 98.69 size-4096: 556KB 556KB 100.0 pte_chain: 158KB 489KB 32.39 sgpool-MAX_PHYS_SEGMENTS: 420KB 480KB 87.50 biovec-128: 390KB 390KB 100.0 size-2048: 352KB 352KB 100.0 size-1024: 348KB 348KB 100.0 size-32: 317KB 324KB 97.57 ext3_inode_cache: 171KB 240KB 71.22 sgpool-64: 213KB 232KB 91.93 signal_act: 212KB 212KB 100.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/