Re: [PATCH v4 0/3] arm64: support page mapping percpu first chunk allocator
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From: Kefeng Wang <hidden>
Date: 2021-10-11 01:09:42
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On 2021/10/11 5:36, Andrew Morton wrote:
On Fri, 10 Sep 2021 13:33:51 +0800 Kefeng Wang [off-list ref] wrote:quoted
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? .
Thanks Andrew. A specific memory layout is required(also with KASAN enabled), we met this issue at qemu and real hardware, due to KASAN enabled, so I think 5.16-rc1 is sufficient. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel