Messages in this thread |  | | | Date | Wed, 25 Mar 2009 20:32:11 -0400 | | From | Ric Wheeler <> | | Subject | Re: Linux 2.6.29 |
| |
Bron Gondwana wrote: > On Wed, Mar 25, 2009 at 04:23:08PM -0700, Linus Torvalds wrote: > >> On Wed, 25 Mar 2009, Theodore Tso wrote: >> >>>> The problem being that unlike the ratio, there's no sane default value >>>> that you can at least argue is not _entirely_ pointless. >>>> >>> Well, if the maximum time that someone wants to wait for an fsync() to >>> return is one second, and the RAID array can write 100MB/sec >>> >> How are you going to tell the kernel that the RAID array can write >> 100MB/s? >> >> The kernel has no idea. >> > > Not at boot up, but after it's been using the RAID array for a little > while it could... > > Bron (... imagining a tunable "max_fsync_wait_target_centisecs = 100" > which caused the kernel to notice how long flushes were taking > and tune its buffer sizes to be approximately right over time ) > This tuning logic is the core of what Josef Bacik did for the transaction batching code for ext4.... ric
|  |