CONFIG_FS_SYNC in Sharp kernel source

[Anonymous]

asshole TKC still alive? hehe...

Oh yes...if you choose to throw stones, why hide behing the vail of anonymity.  Cowardice is a poor quality.

[agosine]

Thanks derekp.  I finally registered so I don\'t get caught up in this guest nonsense.

[Anonymous]

it\'s me

--sashz

[Anonymous]

Ahh sash...yeah I figured it was you...not too many childish folks running around on these forums.

Dude...I have no idea what your beef is with TKC or Proto or whatever...but I personally \"had\" no issues with you.  In fact I was helping your team with wireless issues (talk to Laze).  My kernel had nothing to do with you or your work, or your childish issues you had with proto, etc.  So for you to call me an \"asshole\" is not only uncalled for, but also shows your true intelligence level.  Personally sash, I would stop picking fights with people who did nothing to you (me) and take your energies and focus them elsewhere.  In otherwords, you probably should grow up.

[ScottYelich]

please... not again.

ok?

[ScottYelich]

please.

[derekp]

I\'ve noticed that the kernel I uploaded finally showed up in the downloads section, so I went ahead and removed the attachment from my earlier post.  Actually, it\'s there twice, since I re-uploaded it after a few days thinking that there was a problem with the original upload.  One\'s just the kernel itself, the other one is in a zip file, but otherwise they\'re the same thing.
How shoud I bring it to the site admin\'s attention to remove the redundant one?  Should I send a private message to offroadgeek?

Another note, this kernel is also compiled with support for ext3 filesystem.  If you do a \"tune2fs -j /dev/mmcda1\" then it will turn journaling on.  This might be desirable, seeing as how you\'d otherwise have a higher chance of filesystem corruption with async writes (i.e., if you pull out the SD card without ejecting it).   For the record, I don\'t notice any performance penalty with the journaling.

[agosine]

Derek,  are you sure about this command \"tune2fs -j /dev/mmcda1\".  tune2fs doesn\'t know what the -j flag is on my unit.  I\'m using your zImage file and the TKC ROM2alpha3 BIN file.

[maslovsky]

Another note, this kernel is also compiled with support for ext3 filesystem. If you do a \"tune2fs -j /dev/mmcda1\" then it will turn journaling on. This might be desirable, seeing as how you\'d otherwise have a higher chance of filesystem corruption with async writes (i.e., if you pull out the SD card without ejecting it). For the record, I don\'t notice any performance penalty with the journaling.

That\'s an interesting idea. What abotu space? How much do you think is the overhead?

BTW, I\'ve tried running some benchmarks without shsync process. The transfer rate is even higher - up to 1.5 Mb/sec, but then it\'s a pain if you need to eject a card. It would  take a few seconds to flash the buffers. So I ended up with leaving shsync alone...

[derekp]

agosine, you might need to grab a different version of tune2fs.  I\'m run openzaurus from my SD card, which has the -j (journal) flag, but if I remember right, the version on the sharp rom doesn\'t have it.
Back a while ago, I compiled a bunch of standard linux utilities for the Z, I think a copy of tune2fs was one of them.  I\'ll do some digging and mail it to you if I find it.

[derekp]

Another note, this kernel is also compiled with support for ext3 filesystem. If you do a \"tune2fs -j /dev/mmcda1\" then it will turn journaling on. This might be desirable, seeing as how you\'d otherwise have a higher chance of filesystem corruption with async writes (i.e., if you pull out the SD card without ejecting it). For the record, I don\'t notice any performance penalty with the journaling.

That\'s an interesting idea. What abotu space? How much do you think is the overhead?

BTW, I\'ve tried running some benchmarks without shsync process. The transfer rate is even higher - up to 1.5 Mb/sec, but then it\'s a pain if you need to eject a card. It would  take a few seconds to flash the buffers. So I ended up with leaving shsync alone...

The smallest size journal you can have is 1 block, which should be 1K using the default block size.  Not sure what the default size is.

Also, as you are probably aware, when doing async io on flash media, any increase in raw transfer rate is artificial, that is once you include the time to sync the filesystem you end up with about the same speed as with sync writes (you have to \"pay the piper eventually\", so to speak).  And given enough data, you eventually run out of ram so you\'d have to wait for the data to write out at that point.  On a drive that has physical head movement, there are significant real speedups, as data can be written in a more efficient order.   On the other hand, async i/o also filters out redundant writes.  So in the case of writing out a bunch of smaller files where it has to update the same disk blocks (inode table) multiple times, you get a real speed up.

As far as speed differences between running with v.s. without a journal, I haven\'t done any formal benchmarking, but untaring something with sync i/o takes about a second to write out each file,  whereas with async an untar command flies by.  And it still flies by with about the same speed with journaling on.

[maslovsky]

Thanks for the info. I may try to build myself a kernel with ext3 support. The only pronlem is that when preparing the new ROM  I\'ve been  flashing ROMs back and forth like crazy, so I\'m tired of that  and want to settle down a bit

[ScottYelich]

I hope the next pdaxrom has this option.

Scott

[zbones]

Derekp I have tested this and posted my results here :-
http://www.zaurususergroup.com/index.php?n...iewtopic&t=2292

Many thanks for discovering this, it really works.

Peter.

[maslovsky]

I hope that X11 and Qtopia ROMs will have compatible, if not the same kernels. Ill work with sash on that.