Hi Ben, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on 7cb79f433e75b05d1635aefaa851cfcd1cb7dc4f] url: https://github.com/intel-lab-lkp/linux/commits/Ben-Gardon/KVM-x86-mmu-Rename-slot-rmap-walkers-to-add-clarity-and-clean-up-code/20230203-023259 base: 7cb79f433e75b05d1635aefaa851cfcd1cb7dc4f patch link: https://lore.kernel.org/r/20230202182809.1929122-12-bgardon%40google.com patch subject: [PATCH 11/21] KVM: x86/MMU: Cleanup shrinker interface with Shadow MMU config: x86_64-randconfig-a002 (https://download.01.org/0day-ci/archive/20230204/202302042127.gbKNDVaL-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/c1170de906dfe1ee64da0066e7c28d35e716ed18 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Ben-Gardon/KVM-x86-mmu-Rename-slot-rmap-walkers-to-add-clarity-and-clean-up-code/20230203-023259 git checkout c1170de906dfe1ee64da0066e7c28d35e716ed18 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kvm/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> arch/x86/kvm/mmu/mmu.c:3148:15: warning: no previous prototype for 'mmu_shrink_scan' [-Wmissing-prototypes] 3148 | unsigned long mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) | ^~~~~~~~~~~~~~~ vim +/mmu_shrink_scan +3148 arch/x86/kvm/mmu/mmu.c 3147 > 3148 unsigned long mmu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 3149 { 3150 struct kvm *kvm; 3151 int nr_to_scan = sc->nr_to_scan; 3152 unsigned long freed = 0; 3153 3154 mutex_lock(&kvm_lock); 3155 3156 list_for_each_entry(kvm, &vm_list, vm_list) { 3157 /* 3158 * Never scan more than sc->nr_to_scan VM instances. 3159 * Will not hit this condition practically since we do not try 3160 * to shrink more than one VM and it is very unlikely to see 3161 * !n_used_mmu_pages so many times. 3162 */ 3163 if (!nr_to_scan--) 3164 break; 3165 3166 /* 3167 * n_used_mmu_pages is accessed without holding kvm->mmu_lock 3168 * here. We may skip a VM instance errorneosly, but we do not 3169 * want to shrink a VM that only started to populate its MMU 3170 * anyway. 3171 */ 3172 if (!kvm->arch.n_used_mmu_pages && 3173 !kvm_shadow_mmu_has_zapped_obsolete_pages(kvm)) 3174 continue; 3175 3176 freed = kvm_shadow_mmu_shrink_scan(kvm, sc->nr_to_scan); 3177 3178 /* 3179 * unfair on small ones 3180 * per-vm shrinkers cry out 3181 * sadness comes quickly 3182 */ 3183 list_move_tail(&kvm->vm_list, &vm_list); 3184 break; 3185 } 3186 3187 mutex_unlock(&kvm_lock); 3188 return freed; 3189 } 3190 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
