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Hi guys, I've been told that in Linux 2.6.35 if an application tries to write to a FLASH memory, but the FLASH is not ready, then the application's CPU is ...
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  1. #1
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    Writing to FLASH memory takes application's CPU


    Hi guys,

    I've been told that in Linux 2.6.35 if an application tries to write to a FLASH memory, but the FLASH is not ready, then the application's CPU is being "transferd" to the FLASH manipulation driver.
    I've been also told that a patch was made to stop this behavior.

    Can someone point me to this patch becuase I can't find it myself?

    Thank you!
    Hadar

  2. #2
    Linux Newbie reginaldperrin's Avatar
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    Hmmm... not sure what is going on. Your description is a little vague.
    However, from a hardware point of view, if the flash drive is USB, then the CPU handles read/writes anyway. This is not like the similar, but not so popular (Apple) Firewire, which has it's own chip in the port (and is therefore potentially faster).
    If you see messages relating to CPU being used, this is possibly normal behaviour anyway, though it would seem not to be normal to display such a message.
    Hope this helps.

  3. #3
    Linux Guru Rubberman's Avatar
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    Are you talking about a flash memory card such as a USB thumb drive or SD card? Or are you talking about system flash memory on the motherboard?
    Sometimes, real fast is almost as good as real time.
    Just remember, Semper Gumbi - always be flexible!

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    I'm talking about a NAND flash device on the motherboard. My application writes log to a file, and I suspect that sometimes the write procedure takes precious time from my app's CPU slice.

    Any feedback on this?

    tnx

    Quote Originally Posted by Rubberman View Post
    Are you talking about a flash memory card such as a USB thumb drive or SD card? Or are you talking about system flash memory on the motherboard?

  5. #5
    Linux Guru Rubberman's Avatar
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    I'm not familiar with this driver, but I suspect that it preempts your code and does not return to user space until the transfer is complete, a synchronous operation, rather than a non-blocking one. You might want to look on the kernel.org web site, or post the question to the Linux Foundation forums.
    Sometimes, real fast is almost as good as real time.
    Just remember, Semper Gumbi - always be flexible!

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