Date: Thu, 1 Oct 2009 20:13:29 GMT From: Aditya Sarawgi <truncs@FreeBSD.org> To: Perforce Change Reviews <perforce@FreeBSD.org> Subject: PERFORCE change 169103 for review Message-ID: <200910012013.n91KDTa1061632@repoman.freebsd.org>
next in thread | raw e-mail | index | archive | help
http://perforce.freebsd.org/chv.cgi?CH=169103 Change 169103 by truncs@aditya on 2009/10/01 20:13:08 Make the comment more verbose - include why these parameters were introduced in orlov block allocator. Affected files ... .. //depot/projects/soc2009/soc_ext2fs/src/sys/fs/ext2fs/fs.h#4 edit Differences ... ==== //depot/projects/soc2009/soc_ext2fs/src/sys/fs/ext2fs/fs.h#4 (text+ko) ==== @@ -57,15 +57,26 @@ /* * The path name on which the file system is mounted is maintained * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in - * the super block for this name. AVFPDIR is the expected number of - * files per directory. AVGDIRSIZE is obtained by multiplying AVFPDIR - * and AVFILESIZ which is assumed to be 16384. Both AVFPDIR and AVFFIZSIZ - * are taken from UFS and they are used in implementation of Orlov Block - * Allocator. + * the super block for this name. */ #define MAXMNTLEN 512 + +/* + * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine + * tune the layout preferences for directories within a filesystem. + * His algorithm can be tuned by adjusting the following parameters + * which tell the system the average file size and the average number + * of files per directory. These defaults are well selected for typical + * filesystems, but may need to be tuned for odd cases like filesystems + * being used for sqiud caches or news spools. + * AVFPDIR is the expected number of files per directory. AVGDIRSIZE is + * obtained by multiplying AVFPDIR and AVFILESIZ which is assumed to be + * 16384. + */ + #define AFPDIR 64 #define AVGDIRSIZE 1048576 + /* * Macros for access to superblock array structures */
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200910012013.n91KDTa1061632>