Re: scsi vs ide performance on fsync's

Chris Mason
2001-03-02T19:40:18Z

On Friday, March 02, 2001 01:25:25 PM -0600 Steve Lord <lord@sgi.com> wrote:

>> For why ide is beating scsi in this benchmark...make sure tagged queueing
>> is on (or increase the queue length?). For the xlog.c test posted, I
>> would expect scsi to get faster than ide as the size of the write
>> increases.
>
> I think the issue is the call being used now is going to get slower the
> larger the device is, just from the point of view of how many buffers it
> has to scan.

filemap_fdatawait, filemap_fdatasync, and fsync_inode_buffers all restrict
their scans to a list of dirty buffers for that specific file. Only
file_fsync goes through all the dirty buffers on the device, and the ext2
fsync path never calls file_fsync.

Or am I missing something?

-chris