Re: Linux 2.6.29
From: Jeff Garzik
Date: Sat Mar 28 2009 - 21:25:32 EST
david@xxxxxxx wrote:
ted's suggestion (in his blog) to tweak fsync to 'misbehave' when laptop
mode is enabled (only pushing data out to disk when the disk is awake
anyway, or the time has hit) would really work well for most users.
servers (where you have the data integrity fsync useage) don't use
laptop mode. desktops could use 'laptop mode' with a delay of 0.5 or 1
second and get prety close the the guarentee that users want without a
huge performance hit.
The existential struggle is overall amusing:
Application writers start using userland transactional databases for
crash recovery and consistency, and in response, OS writers work to
undercut the consistency guarantees currently provided by the OS.
More seriously, if we get sqlite, db4 and a few others behaving sanely
WRT fsync, you cover a wide swath of apps all at once.
I absolutely agree that db4, sqlite and friends need to be smarter in
the case of laptop mode or overall power saving.
Jeff
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