On Monday 03 December 2007 22:26:28 Nick Piggin wrote: > There is one slight downside -- direct block device access and filesystem > metadata access goes through an extra copy and gets stored in RAM twice. > However, this downside is only slight, because the real buffercache of the > device is now reclaimable (because we're not playing crazy games with it), > so under memory intensive situations, footprint should effectively be the > same -- maybe even a slight advantage to the new driver because it can also > reclaim buffer heads. For the embedded world, initramfs has pretty much rendered initrd obsolete, and that was the biggest user of the ramdisk code I know of. Beyond that, loopback mounts give you more flexible transient block devices than ramdisks do. (In fact, ramdisks are such an amazing pain to use/size/free that if I really needed something like that I'd just make a loopback mount in a ramfs instance.) Embedded users who still want a block interface for memory are generally trying to use a cramfs or squashfs image out of ROM or flash, although there are flash-specific filesystems for this and I dunno if they're actually mounting /dev/mem at an offset or something (md? losetup -o? Beats me, I haven't tried that myself yet...) Rob -- "One of my most productive days was throwing away 1000 lines of code." - Ken Thompson. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
