From: Miklos S. <mi...@sz...> - 2006-03-09 11:51:16
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> i would be interested in knowing how things differ in the way the kernel > fuse module handles read/write when specifying the > direct_io as compared to when not. As far as I understood, in the normal > case without the direct_io, all data is read into the page cache > when returned from the fuse userspace daemon. But the writes never get stuck > in the page cache but are "written through" each time, > is that correct? Yes. > And when the direct_io is used how do these things look instead? The page cache is not involved. Data to/from read/write syscalls is directly transfered from/to userspace filesystem. > Is there somewhere some brief interaction diagram explaining how these > things interact (the fuse library, the "blockdriver" > communicating with the userspace, the page cache, ...)? The kernel-userspace communication is described in doc/kernel.txt Miklos |