Hi Sven,
> Message du 25/07/08 12:36 > De : "Sven Garly" <[EMAIL PROTECTED]> > A : [email protected] > Copie à : > Objet : [ntfs-3g-devel] Question about ntfs_fuse_* functions > > > I've been playing with NTFS-3G on an ARM system and have been looking > at why performance is so low compared with other file systems (I get > 2.1MB/s on write; FAT32, EXT3 and HFS+ all do about 17MB/s). > > One of the things that struck me was that in ntfs_fuse_read and > ntfs_fuse_write most of the time is spent opening and closing the > internal inode.. That is a consequence of using the high-level fuse interface, for any action on a file you have to get its context from the file name. > > Moving the ntfs_inode_open to ntfs_fuse_open and ntfs_inode_close to a > newly created ntfs_fuse_release, my performance jumps to 6.1MB/s - a > bit better. Do you mean you keep the inode open ? You may have problems with concurrent access to the file. You could also get into problems after a power shortage. I would rather suggest you cache inode numbers. I got significant improvements this way (halved the cpu usage). Have a try with http://pagesperso-orange.fr/b.andre/security.html I still admit the top four functions which make the most use of the cpu are related to finding an inode from path. > > For the most part this seems to work (Iozone seems to have some issues > that go away if I use debug mode or use this version of NTFS-3G on an > Intel platform). I have noticed that ntfs_inode_open seems to create a > new inode - might this cause problems if multiple open of the file > were performed? > > Is there a reason for the approach that has been taken? > > -- > Sven Regards Jean-Pierre ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ ntfs-3g-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ntfs-3g-devel
