On Sun, 24 Aug 2014 01:49:07 -0400, nick said: > After searching through parts of the btrfs code and docs. I am unable to find any information > on the helper threads in btrfs and would like to known more about how their implemented and > what are the reasons for helper threads in btrfs versus only 1 for journaling in ext3/ext3. Really? *REALLY*? You can't find anything? What searching did you *DO*? [~] cd /usr/src/linux-next/ [/usr/src/linux-next] ls fs/btrfs Kconfig btrfs_inode.h delayed-ref.h extent-tree.o hash.c locking.o props.h root-tree.o transaction.c volumes.h Makefile built-in.o delayed-ref.o extent_io.c hash.h lzo.c props.o scrub.c transaction.h volumes.o acl.c check-integrity.c dev-replace.c extent_io.h hash.o lzo.o qgroup.c scrub.o transaction.o xattr.c acl.o check-integrity.h dev-replace.h extent_io.o inode-item.c math.h qgroup.h send.c tree-defrag.c xattr.h async-thread.c compression.c dev-replace.o extent_map.c inode-item.o modules.order qgroup.o send.h tree-defrag.o xattr.o async-thread.h compression.h dir-item.c extent_map.h inode-map.c ordered-data.c raid56.c send.o tree-log.c zlib.c async-thread.o compression.o dir-item.o extent_map.o inode-map.h ordered-data.h raid56.h struct-funcs.c tree-log.h zlib.o backref.c ctree.c disk-io.c file-item.c inode-map.o ordered-data.o raid56.o struct-funcs.o tree-log.o backref.h ctree.h disk-io.h file-item.o inode.c orphan.c rcu-string.h super.c ulist.c backref.o ctree.o disk-io.o file.c inode.o orphan.o reada.c super.o ulist.h btrfs.ko delayed-inode.c export.c file.o ioctl.c print-tree.c reada.o sysfs.c ulist.o btrfs.mod.c delayed-inode.h export.h free-space-cache.c ioctl.o print-tree.h relocation.c sysfs.h uuid-tree.c btrfs.mod.o delayed-inode.o export.o free-space-cache.h locking.c print-tree.o relocation.o sysfs.o uuid-tree.o btrfs.o delayed-ref.c extent-tree.c free-space-cache.o locking.h props.c root-tree.c tests volumes.c Now take a look there in the left-hand column. You *might* find something useful there. As to the rest of your question, the ext filesystems have as a design goal good performance on 1-2 core machines, while btrfs was designed to take advantage of high-core-count machines. Hopefully you're a good enough programmer that I don't have to explain further.
Attachment:
pgpBfhR3boz0g.pgp
Description: PGP signature
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
