Messages in this thread |  | | From | Andreas Dilger <> | Date | Thu, 18 Oct 2001 09:28:37 -0600 | Subject | Re: Poor floppy performance in kernel 2.4.10 |
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On Oct 18, 2001 12:11 +0200, Kamil Iskra wrote: > So, to reiterate, the conditions known to be necessary to reproduce it > are: kernel >=2.4.10 (perhaps only the Linus series), small files or > directory operations, mtools. The behaviour is as if no caching was done, > there is a slowdown by a factor of two. I have this problem both on my > laptop and on the desktop machine at work. They are running different > kernel versions (2.4.12 and 2.4.10), differently configured and compiled > by two different people. Kernel 2.4.9 and earlier worked fine.
I think this is a result of the "blockdev in pagecache" change added in 2.4.10. One of the byproducts of this change is that if a block device is closed (no other openers) then all of the pages from this device are dropped from the cache. In the case of a floppy drive, this is very important, as you don't want to be cacheing data from one floppy after you have inserted a new floppy.
In contrast, if you mounted the floppy instead of using mtools, it would probably have good performance for small files as well.
Cheers, Andreas -- Andreas Dilger \ "If a man ate a pound of pasta and a pound of antipasto, \ would they cancel out, leaving him still hungry?" http://www-mddsp.enel.ucalgary.ca/People/adilger/ -- Dogbert
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