Possibility to increase thread count & change DOKAN_OPTION_ALLOW_IPC_BATCHING? (FUSE) about dokany

[LTRData]

I'm a little confused... I don't mind the source code having both Dokany & FUSE code, but how does one do that?

The problem here was apparently that if you create a native Dokany implementation, this is very easy to set from your implementation by setting a flag in the options structure when mounting a new file system.

If on the other hand you implement a file system using the Fuse emulation layer on top of Dokany, this option is hidden in the emulation layer and not exposed to your implementation.

[algj]

Oh my!!! Thank you very much @Liryna for the PR!! ❤️ I thought I'll have to do the PR myself 😅

[Liryna]

The problem is that those DOKAN_OPTIONS_* are not directly available for FUSE, they need to be wrapped for the FUSE interface. See here for DOKAN_OPTION_MOUNT_MANAGER

[Liryna]

Looks like the IPC_BATCHING option was not correctly set in the library aef92bc :(
(The CI tests seems to fail, I will need to look at that https://ci.appveyor.com/project/Maxhy/dokany/builds/49214019 )

Regarding ThreadCount, I don't think that's a good idea as like I said before, it does not scale correctly. Right now the best performance-wise thread count is allocated and for slow IO we need to use the thread pool.

[Liryna]

Hi @algj ,
Have you tried DOKAN_OPTION_ALLOW_IPC_BATCHING ? There is no FUSE option (yet) but if you could force it and see if it helps your case.
Increasing main pull thread count is a limited solution that does not scale well with increase of IO activity.

[algj]

Oh! Thank you @Liryna! This is exactly what I was looking for! Unfortunately (from my understanding) you cannot change it without recompiling Dokany. There should be a way to change this option somehow (possibly thread count too if we're at it)

I hope someone makes a PR regarding changing this option easily... 🙂

[LTRData]

No, the DOKAN_OPTIONS_* flags can be set in Options field in DOKAN_OPTIONS structure when mounting a new file system. It does not need recompiling driver or library.

[algj]

I'm a little confused... I don't mind the source code having both Dokany & FUSE code, but how does one do that?

[algj]

I have tried out IPC_BATCHING. There is a clear performance difference when I did my tests (it's slower by a few ms consistently), but for some reason it still sticks to 2 threads...? I did the same tests on Linux too, it was definitely handling concurrent reads/writes on Linux much better. I'm not sure if I'm misunderstanding something, I thought it's supposed to spawn new threads when there's a few of concurrent reads instead of blocking it all.

[algj]

Also, I think that ThreadCount should be added back. I guess SingleThread option could be removed, but that would break some things.

ThreadCount = 0, library decides what thread count to use
ThreadCount = 1, single threaded
ThreadCount >= 2, multi thread, user defines how many threads application should use