Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 29 Aug 2003 13:49:51 -0400 | From | Ed Sweetman <> | Subject | Re: [RFC] extents support for EXT3 |
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Alex Tomas wrote: >>>>>>Ed Sweetman (ES) writes: > > > ES> I was testing this with only a single partition mounted with extents > ES> enabled when benchmarking. Ext3 gave no messages of being mounted > ES> afterbootup with or without extents so to make sure i had extents > ES> enabled i booted with all my partitions with the extents option. I > ES> suspect then my problems began. I'm completely unaware of the extent > ES> of the damage enabling extents has done since most of the important > ES> things were opened, not created during my extents use. In any case it > ES> may be that the reason why init is not able to be found is because i > ES> used apt and upgraded my system ...and I dont remember if i had > ES> extents enabled at the time or not. If my init is in extents format > ES> though, then why is a patched kernel able to read it with extents not > ES> being enabled via the omunt option where as kernels without the patch > ES> cannot. Is extents able to be read from a fs even when it's not > ES> mounted with the option but not written? I'm kinda confused, this > ES> aspect of extents wasn't in the original email. > > well, on my testbox I use _patched with extents_ ext3 as / and /boot partitions. > I haven't seen any problems on them. with patch, ext3 look at special EXTENTS > flag in inode (this flag is set up only for newly created files on fs being > mounted with extents enabled) and calls apropriate routines. thus, it will > call extents routines for those file even if fs is being mounted with extents > disabled. I really do believe that your root filesystem haven't been mounted > with extents enabled, so init must be stored in good old format.
Ok well little wait on the non-patched bootup.
I booted with test4-mm2 patched
Throughput 221.812 MB/sec 16 procs ext2 Throughput 159.495 MB/sec 16 procs ext3-extents (definitely enabled) Throughput 147.598 MB/sec 16 procs ext3 (patched but disabled)
There is an obvious improvement, but nothing near the 70+% increase you saw. Subsequent runs run anything from a little lower than above for extents to 167MB/s.
I'm using the largest inode size possible for ext3 for the filesystem tested.
By the way, what's the behavior of opening an existing non-extent file and writing and reading to it while the partition is mounted with extents enabled?
> ES> i'm going to try and boot a kernel without the extents patch (so far > ES> hasn't been possible) and run dbench again and see if i get different > ES> numbers. I'm almost suspecting extents being enabled no matter what i > ES> mount the fs's as. > > that would be fine! > >
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