[lkml]   [2008]   [Sep]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: vfat file system extreme fragmentation on multiprocessor
Why should C library fwrite() split anything? There is no good reason (unless in x86 64 KByte segmented model trying to emulate a flat model - old DOS). The 50 MByte go to write() in a single piece here.

There are only very little "single operation"s in kernel nowadays. In most cases this is a good thing.

Looks like fat/fatent.c fat_alloc_clusters() is limited to allocate only 4 clusters under a single lock.

Found another assumption I do not like: cluster size >= 512. There are old FAT systems on SRAM cards having 128 byte/sector and cluster. But I don't want to have long filenames on them. Hope the 512 does not sit elsewhere, too.

fat/inode.c __fat_get_block() /* TODO: multiple cluster allocation would be desirable */
YES, OF COURSE. Only a single cluster is allocated at a time, no lock here, I can be happy I got still 8 clusters per fragment, might have been only 1.


 \ /
  Last update: 2008-09-12 02:27    [W:0.029 / U:1.592 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site