Il 20/11/2013 00:00, Luigi Rizzo ha scritto: > I recently found out that without kvm enabled, and especially > with -smp 2 or greater, qemu becomes incredibly slow > (to the point that you can see kernel messages in the > quest print one character at a time). > > This happens with a Linux host (even with -smp 1) > and with FreeBSD host (in this case -smp 2 or greater; > -smp 1 seems to work fine there).
I could not reproduce it; the profile here seems normal, too: 24,69% perf-3281.map [.] 0x00007f4ab5ac9903 14,18% qemu-system-x86_64 [.] cpu_x86_exec 2,67% libglib-2.0.so.0.3800.1 [.] g_source_iter_next 2,63% qemu-system-x86_64 [.] tcg_optimize 2,47% qemu-system-x86_64 [.] helper_pcmpeqb_xmm 2,28% qemu-system-x86_64 [.] phys_page_find 1,92% qemu-system-x86_64 [.] address_space_translate_internal 1,53% qemu-system-x86_64 [.] tcg_liveness_analysis 1,40% qemu-system-x86_64 [.] tcg_reg_alloc_op 1,17% qemu-system-x86_64 [.] helper_psubb_xmm 0,97% qemu-system-x86_64 [.] disas_insn 0,96% qemu-system-x86_64 [.] cpu_x86_handle_mmu_fault 0,92% qemu-system-x86_64 [.] tcg_out_opc 0,92% qemu-system-x86_64 [.] helper_pmovmskb_xmm 0,91% qemu-system-x86_64 [.] tlb_set_page 0,75% qemu-system-x86_64 [.] address_space_translate 0,74% qemu-system-x86_64 [.] ldq_phys 0,61% qemu-system-x86_64 [.] tcg_gen_code 0,58% qemu-system-x86_64 [.] helper_le_ldq_mmu 0,56% qemu-system-x86_64 [.] helper_ctz This is on Linux, -smp 2, booting a RHEL6.4 guest. Paolo
