On Tue, Apr 1, 2014 at 8:59 PM, One Thousand Gnomes <gnomes@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 01 Apr 2014 01:16:07 +0400 > Konstantin Khlebnikov <koct9i@xxxxxxxxx> wrote: > >> This patch adds 256 virtual character devices: /dev/byte0, ..., /dev/byte255. >> Each works like /dev/zero but generates memory filled with particular byte. > > More kernel code for an ultra-obscure corner case that can be done in > user space > > I don't see the point True. That was a long-planned joke. But at the final moment I've found practical usage for it and overall design became not such funny. Currently I'm thinking about single-device model proposed by Kirill. Let's call it /dev/poison. Application can open it, write a poison (up to a page size) and after that this instance will generate pages filled with this pattern. I don't see how this can be done in userspace without major memory/cpu overhead caused by initial memset. Default poison might be for example 0xff, so it still will be useful for 'dd'. -- 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>