On Fri, 10 Sep 2021 13:33:51 +0800 Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote: > Percpu embedded first chunk allocator is the firstly option, but it > could fails on ARM64, eg, > "percpu: max_distance=0x5fcfdc640000 too large for vmalloc space 0x781fefff0000" > "percpu: max_distance=0x600000540000 too large for vmalloc space 0x7dffb7ff0000" > "percpu: max_distance=0x5fff9adb0000 too large for vmalloc space 0x5dffb7ff0000" > > then we could meet "WARNING: CPU: 15 PID: 461 at vmalloc.c:3087 pcpu_get_vm_areas+0x488/0x838", > even the system could not boot successfully. > > Let's implement page mapping percpu first chunk allocator as a fallback > to the embedding allocator to increase the robustness of the system. > > Also fix a crash when both NEED_PER_CPU_PAGE_FIRST_CHUNK and KASAN_VMALLOC enabled. How serious are these problems in real-world situations? Do people feel that a -stable backport is needed, or is a 5.16-rc1 merge sufficient?
