On Tue, Feb 20, 2018 at 3:30 PM Luck, Tony <tony.luck@xxxxxxxxx> wrote: > [1] I didn't dig through the Linux code to check whether we manage to > get those four SMIs from a single EFI call, or whether we make multiple > EFI calls to open/read/close one file. It is possible that we stink a > bit too if we are doing more EFI calls than required. read() will make two calls - one to obtain the size of the variable, the other to read it. It looks like cat will also trigger an fstat(), so we're probably also making a call for that. There's presumably some optimisation that could be made there if we trust the firmware not to change the size behind our back. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html