On Wed, 2 May 2007, Björn Steinbrink wrote: > On 2007.05.02 15:04:44 +0100, Hugh Dickins wrote: > > On Tue, 1 May 2007, Phillip Susi wrote: > > > I seem to remember seeing some patches go by at some point that > > > allowed one of the rom type embeded system filesystems to directly > > > execute binaries out of the original rom memory rather than copying > > > them to ram first, then executing from there. I was wondering if > > > rootfs or tmpfs support such execute in place today, or if binaries > > > executed from there have their code segments duplicated in ram? > > > > Only ext2 supports it today: see Documentation/filesystems/xip.txt > > As I understand it, xip avoids the page cache copy. But tmpfs already > lives in the page cache (or swap), so avoiding that "copy" is > impossible. But I always expected tmpfs to implicitly due its own kind > of xip, i.e. that it doesn't have to store its stuff in the page cache > twice. Are you saying that this isn't true?
tmpfs doesn't store its stuff in the page cache twice: that's true, and I didn't mean to imply otherwise. But tmpfs doesn't contain any support for rom memory: you'd have to copy from rom to tmpfs to use it. Hugh
