On Wed, 27 Aug 2014 14:30:55 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 27 Aug 2014 16:22:20 -0500 (CDT) Christoph Lameter <cl@xxxxxxxxx> wrote: > > > > Some explanation of why one would use ext4 instead of, say, > > > suitably-modified ramfs/tmpfs/rd/etc? > > > > The NVDIMM contents survive reboot and therefore ramfs and friends wont > > work with it. > > See "suitably modified". Presumably this type of memory would need to > come from a particular page allocator zone. ramfs would be unweildy > due to its use to dentry/inode caches, but rd/etc should be feasible. If you took one of the existing ramfs types you would then need to - make it persistent in its storage, and put all the objects in the store - add journalling for failures mid transaction. Your dimm may retain its bits but if your CPU reset mid fs operation its got to be recovered - write an fsck tool for it - validate it at which point it's probably turned into ext4 8) It's persistent but that doesn't solve the 'my box crashed' problem. Alan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>