Very nice! We will try to integrate it in time. Thanks a lot for fast response! Regards Johan ----- Original Message ----- From: "Charles Manning" To: Cc: "Johan Kotlinski" Sent: Friday, February 05, 2010 5:05 AM Subject: Re: [Yaffs] multithreading question > On Wednesday 03 February 2010 23:17:42 Johan Kotlinski wrote: >> Hi Charles! >> >> Thanks for your answer. Yes, I was talking about yaffs direct. >> Page-by-page >> locking is of course all right. >> >> I have another question. Our NAND chip has the ability to prefetch pages. >> I >> imagine we could benefit from this. Is there a way to get a hint from >> yaffs >> what it is about to read next? Or do you know some good place to insert >> such an optimization? >> >> Best regards, >> Johan >> > I have just checked in code which breaks up long reads and writes into > smaller > sub read/writes. > > This has the advantage of reducing longing times. > > Please give this a whirl if it is of interest to you. > > -- Charles > > > ----- Original Message ----- >> From: "Charles Manning" >> To: >> Cc: "Johan Kotlinski" >> Sent: Wednesday, February 03, 2010 1:15 AM >> Subject: Re: [Yaffs] multithreading question >> >> > On Tuesday 02 February 2010 00:29:17 Johan Kotlinski wrote: >> >> Hi! >> >> It appears that Yaffs2 multithreading protection is on a very high >> >> level >> >> (mutex wrapping entire fread/fwrite calls). >> > >> > Are you talking about yaffs direct or the Linux yaffs? >> > The linux yaffs will be locked on a page-by-page basis and I am going >> > to >> > change the way yaffs direct does the reading/writing too to only lock >> > on >> > a page-by-page basis. >> > >> > The underlying NAND is locked on a apge by page basis too (that's a >> > limitation >> > of the hardware), so is this really a big concern? >> > >> >> My worry is that if a low-priority task does a large fwrite call, it >> >> could >> >> block high-priority tasks for a long time. Is this an acknowledged >> >> problem? >> > >> > It depends on the OS. Some, without priority inhere, won't have this >> > problem. >> > >> >> Are there comparable file systems that handle multithreading in a more >> >> granular way? >> >> _______________________________________________ >> yaffs mailing list >> yaffs@lists.aleph1.co.uk >> http://lists.aleph1.co.uk/cgi-bin/mailman/listinfo/yaffs > > >