On 8/12/09, Sherry Moore <sherry.moore at sun.com> wrote: > I am sponsoring this fasttrack for Dave Plauger and Steve Sistare. The > timer is set for next Tuesday August 18, 2009. Requesting Micro/Patch > binding. > > The one-pager, project specification and man page diffs are available > in the materials directory. > > Sherry Moore > > Template Version: @(#)sac_nextcase 1.68 02/23/09 SMI > This information is Copyright 2009 Sun Microsystems > > 1. Introduction > 1.1. Project/Component Working Name: > Fast Crash Dump > 1.2. Name of Document Author/Supplier: > Dave Plauger > Steve Sistare > 1.3. Date of This Document: > August 11, 2009 > > 4. Technical Description: > 4.1. Details: > New command line flags to dumpadm(1M) control how core files > are to be saved. The setting is saved across reboots in > /etc/dumpadm.conf. The new default behavior is to save files > in compressed format instead of always uncompressing them, as > it does currently. > > If saving compressed, savecore(1M) copies the core file from > the dump device to vmdump.N, where N is the usual dump > integer. Copying a core file is much faster than uncompressing > it into unix.N and vmcore.N images; and it takes up much less > disk space. On systems that dump to the swap area there is > less risk that the core image will be over-written by swap > activity before it can be extracted. > > savecore(1M) performance has been improved by reading the dump > file with fread(3C) instead of pread(2).
Sherry, the stdio implementation in libc is among the slowest stdio versions out there. If you want to archive better performance you should use the stdio implementation in libast or use mmap(2). Irek
