#214629 - mailutils-imap4d: msync forces disk spinup

Reported by: Christian Häggström <[email protected]>

Date: Tue, 7 Oct 2003 19:33:02 UTC

Severity: minor

Found in version 20030902-1

Report forwarded to [email protected], Jordi Mallach <[email protected]>:
Bug#214629; Package mailutils-imap4d. (full text, mbox, link).

Acknowledgement sent to Christian Häggström <[email protected]>:
New Bug report received and forwarded. Copy sent to Jordi Mallach <[email protected]>. (full text, mbox, link).

Package: mailutils-imap4d Version: 20030902-1 Severity: minor I'm using the noflushd utility to keep my computer quiet, by spinning down the disks. However, each time someone checks their mail, the disk is spinning up. Other IMAP servers, for example uw-imapd, does not require the disk to spin up. I think the cause is the msync calls at mailbox/mapfile_stream.c, this is a code snippet from function _mapfile_size: if (mfs->ptr == MAP_FAILED) return EINVAL; if (mfs->ptr) msync (mfs->ptr, mfs->size, MS_SYNC); if (fstat(mfs->fd, &stbuf) != 0) return errno; if (mfs->size != (size_t)stbuf.st_size) If it is requred to sync mmap'ed pages before fstat (the man pages do not mention anything about this), then there must be some other way to flush the pages, without disk access. -- System Information: Debian Release: testing/unstable Architecture: i386 Kernel: Linux saturn 2.4.20 #15 Sat May 3 05:08:04 CEST 2003 i586 Locale: LANG=C, LC_CTYPE=sv_SE Versions of packages mailutils-imap4d depends on: ii libc6 2.3.2-8 GNU C Library: Shared libraries an ii libcomerr2 1.34+1.35-WIP-2003.08.21-3 The Common Error Description libra ii libgcrypt1 1.1.12-4 LGPL Crypto library - runtime libr ii libgdbm3 1.8.3-2 GNU dbm database routines (runtime ii libgnutls7 0.8.9-2 GNU TLS library - runtime library ii libgsasl1 0.0.6-1 GNU SASL library ii libidn9 0.1.14-2 GNU libidn library, implementation ii libkrb53 1.3-2 MIT Kerberos runtime libraries ii libmailutils0 20030902-1 GNU Mail abstraction library ii libmysqlclien 3.23.56-2 LGPL-licensed client library for M ii libpam0g 0.76-14 Pluggable Authentication Modules l ii libtasn1-0 0.1.2-1 Manage ASN.1 structures (runtime) ii netbase 4.13 Basic TCP/IP networking system ii zlib1g 1:1.1.4-15 compression library - runtime -- no debconf information

Reply sent to Jordi Mallach <[email protected]>:
You have marked Bug as forwarded. (full text, mbox, link).

Hello, I got this bug report a few weeks ago. It's a weird wishlist for a mail server, but if it's doable to improve it, he'll be happier :) Jordi -- Jordi Mallach Pérez -- Debian developer http://www.debian.org/ [email protected] [email protected] http://www.sindominio.net/ GnuPG public key information available at http://oskuro.net/~jordi/

> > > --EeQfGwPcQSOJBaQU > Content-Type: text/plain; charset=iso-8859-1 > Content-Disposition: inline > Content-Transfer-Encoding: quoted-printable > > Hello, > > I got this bug report a few weeks ago. It's a weird wishlist for a mail > server, but if it's doable to improve it, he'll be happier :) > > Jordi > --=20 > Subject: Bug#214629: mailutils-imap4d: msync forces disk spinup > Reply-To: =?iso-8859-1?q?Christian_H=E4ggstr=F6m?= <[email protected]>, > [email protected] > From: =?iso-8859-1?q?Christian_H=E4ggstr=F6m?= <[email protected]> > To: Debian Bug Tracking System <[email protected]> > Date: Tue, 07 Oct 2003 21:23:03 +0200 > > Package: mailutils-imap4d > Version: 20030902-1 > Severity: minor > > I'm using the noflushd utility to keep my computer quiet, by spinning > down the disks. However, each time someone checks their mail, the disk > is spinning up. > Other IMAP servers, for example uw-imapd, does not require the disk to > spin up. > I do not quite understand, why other servers does not require the disk to spin, since checking the mail require to **read** the maildrop, unless you mean it is cache somehow ? > I think the cause is the msync calls at mailbox/mapfile_stream.c, > this is a code snippet from function _mapfile_size: > > if (mfs->ptr == MAP_FAILED) > return EINVAL; > if (mfs->ptr) > msync (mfs->ptr, mfs->size, MS_SYNC); > if (fstat(mfs->fd, &stbuf) != 0) > return errno; > if (mfs->size != (size_t)stbuf.st_size) > The MS_SYNC is needed so we are ... in synch 8-). But if the file is open readonly ... it should not be necessary. So yes, if to checking of emails is done with EXAMINE command the mailbox should be open READ_ONLY so no need for MS_SYNC. Ok, I'll take a look. > If it is requred to sync mmap'ed pages before fstat (the man pages do > not mention anything about this), then there must be some other way to > flush the pages, without disk access. It is not required, since the system should do a good enough job at it. But since mail was consider important for example in the event of crashing etc .. We had to make sure that we have an consisten underlying file, this can be important before/after expunging ... What suprise me is if the file was open RD_ONLY msync() should have been a noop and not affect the file/disk.

Debian Bug report logs - #214629 mailutils-imap4d: msync forces disk spinup

Debian Bug report logs - #214629
mailutils-imap4d: msync forces disk spinup