> -----Original Message----- > From: Xi Ruoyao <xry...@xry111.site> > Sent: Wednesday, January 15, 2025 1:29 PM > To: Tamar Christina <tamar.christ...@arm.com>; gcc-patches@gcc.gnu.org > Cc: nd <n...@arm.com>; Richard Earnshaw <richard.earns...@arm.com>; > ktkac...@gcc.gnu.org; Richard Sandiford <richard.sandif...@arm.com> > Subject: Re: [PATCH]AArch64: have -mcpu=native detect architecture extensions > for unknown non-homogenous systems [PR113257] > > On Sat, 2025-01-11 at 15:18 +0000, Tamar Christina wrote: > > However the same thing works for big.LITTLE as in such system the cores must > > have the same extensions otherwise it doesn't fundamentally work. > > > > i.e. task migration from one core to the other wouldn't work. > > See https://gcc.gnu.org/PR111768 for a potential issue. >
There's no issue there. As Alexander says in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111768#c7 It is not practical for you to have two CPUs in the same system with different capabilities. Your kernel will not work, or you have to disable task migration. The same extends to cache sizes and other properties of the CPU. As an aside, today the big.LITTLE selection already enforces a uniform feature set. Thanks, Tamar > -- > Xi Ruoyao <xry...@xry111.site> > School of Aerospace Science and Technology, Xidian University
