On Thu, 5 Dec 2024 09:57:12 -0500 Xiaoyao Li <xiaoyao...@intel.com> wrote:
> The series is motivated by auditing the usage of CPUState::nr_cores and > CPUState::nr_threads, which is motivated by [1]. > > The initial goal is to initialize nr_threads and nr_cores earlier for > x86, which leads to patches [2] and [3]. Patch [2] touches all the ARCHes > and patch [3] looks hacky. At last Igor suggested to audit nr_threads and > nr_cores, and only set them in the pre_plug() callback for the ARCHes that > really need them[1]. > > By audting nr_threads and nr_cores, I found nr_cores is only used by > x86. So we can introduce a x86 specific one and initialize in > x86_cpu_pre_plug(), then drop nr_cores totally. > > However for nr_threads, it's used by MIPS and PPC as well[4]. There are > two options: > 1. maintain separate substitute in X86/MIPS/PPS, so we can drop > CPUState::nr_threads like for CPUState::nr_cores. > > 2. keep CPUState::nr_threads and find place (or introduce pre_plug()) to > initialize them earlier for MIPS/PPC. > > I would like to seek for opinions for which one is prefered. > > This series implments the drop for CPUState::nr_cores. Though it doesn't > help on the initial goal without the solution for nr_threads, I think it > is still a good cleanup? > > BTW, by initializing nr_threads and nr_cores earlier than > qemu_init_vcpu(), it also unblocks [5]. With minor fixes included mentioned during review Acked-by: Igor Mammedov <imamm...@redhat.com> > > > [1] > https://lore.kernel.org/qemu-devel/20241125103857.78a23...@imammedo.users.ipa.redhat.com/ > [2] > https://lore.kernel.org/qemu-devel/5f8db586-cdda-4d00-be02-f9880a20e...@redhat.com/ > [3] > https://lore.kernel.org/qemu-devel/20241122160317.4070177-1-xiaoyao...@intel.com/ > [4] > https://lore.kernel.org/qemu-devel/045f9cb1-2b17-4b2c-985f-3c34e3626...@intel.com/ > [5] > https://lore.kernel.org/qemu-devel/20231128171239.69b6d...@imammedo.users.ipa.redhat.com/ > > Xiaoyao Li (4): > i386/topology: Update the comment of x86_apicid_from_topo_ids() > i386: Extract a common fucntion to setup value of > MSR_CORE_THREAD_COUNT > i386: Track cores_per_module in CPUX86State > cpu: Remove nr_cores from struct CPUState > > hw/core/cpu-common.c | 1 - > hw/i386/x86-common.c | 4 +++- > include/hw/core/cpu.h | 2 -- > include/hw/i386/topology.h | 5 +++-- > system/cpus.c | 1 - > target/i386/cpu.c | 2 +- > target/i386/cpu.h | 16 ++++++++++++++++ > target/i386/hvf/x86_emu.c | 3 +-- > target/i386/kvm/kvm.c | 5 +---- > target/i386/tcg/sysemu/misc_helper.c | 3 +-- > 10 files changed, 26 insertions(+), 16 deletions(-) >
