On Thu, 11 Jan 2007 10:57:06 +0800 Aubrey <[EMAIL PROTECTED]> wrote: > Hi all, > > Opening file with O_DIRECT flag can do the un-buffered read/write access. > So if I need un-buffered access, I have to change all of my > applications to add this flag. What's more, Some scripts like "cp > oldfile newfile" still use pagecache and buffer. > Now, my question is, is there a existing way to mount a filesystem > with O_DIRECT flag? so that I don't need to change anything in my > system. If there is no option so far, What is the right way to achieve > my purpose?
Not possible, basically. O_DIRECT reads and writes must be aligned to the device's block size (usually 512 bytes) in memory addresses, file offsets and read/write request sizes. Very few applications will bother to do that and will hence fail if their files are automagically opened with O_DIRECT. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
