On 08/02/20 at 07:35pm, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
>
> * Replace magic numbers with defines
> * Replace memblock_find_in_range() + memblock_reserve() with
> memblock_phys_alloc_range()
> * Stop checking for low memory size in reserve_crashkernel_low(). The
> allocation from limited range will anyway fail if there is no enough
> memory, so there is no need for extra traversal of memblock.memory
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> ---
> arch/x86/kernel/setup.c | 40 ++++++++++++++--------------------------
> 1 file changed, 14 insertions(+), 26 deletions(-)
Applied this patch on top of 5.8, crashkernel reservation works well.
And the code change looks good.
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
>
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index d8de4053c5e8..d7ced6982524 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -419,13 +419,13 @@ static int __init reserve_crashkernel_low(void)
> {
> #ifdef CONFIG_X86_64
> unsigned long long base, low_base = 0, low_size = 0;
> - unsigned long total_low_mem;
> + unsigned long low_mem_limit;
> int ret;
>
> - total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT));
> + low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX);
>
> /* crashkernel=Y,low */
> - ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base);
> + ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base);
> if (ret) {
> /*
> * two parts from kernel/dma/swiotlb.c:
> @@ -443,23 +443,17 @@ static int __init reserve_crashkernel_low(void)
> return 0;
> }
>
> - low_base = memblock_find_in_range(0, 1ULL << 32, low_size, CRASH_ALIGN);
> + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, 0, CRASH_ADDR_LOW_MAX);
> if (!low_base) {
> pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n",
> (unsigned long)(low_size >> 20));
> return -ENOMEM;
> }
>
> - ret = memblock_reserve(low_base, low_size);
> - if (ret) {
> - pr_err("%s: Error reserving crashkernel low memblock.\n", __func__);
> - return ret;
> - }
> -
> - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
> + pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n",
> (unsigned long)(low_size >> 20),
> (unsigned long)(low_base >> 20),
> - (unsigned long)(total_low_mem >> 20));
> + (unsigned long)(low_mem_limit >> 20));
>
> crashk_low_res.start = low_base;
> crashk_low_res.end = low_base + low_size - 1;
> @@ -503,13 +497,13 @@ static void __init reserve_crashkernel(void)
> * unless "crashkernel=size[KMG],high" is specified.
> */
> if (!high)
> - crash_base = memblock_find_in_range(CRASH_ALIGN,
> - CRASH_ADDR_LOW_MAX,
> - crash_size, CRASH_ALIGN);
> + crash_base = memblock_phys_alloc_range(crash_size,
> + CRASH_ALIGN, CRASH_ALIGN,
> + CRASH_ADDR_LOW_MAX);
> if (!crash_base)
> - crash_base = memblock_find_in_range(CRASH_ALIGN,
> - CRASH_ADDR_HIGH_MAX,
> - crash_size, CRASH_ALIGN);
> + crash_base = memblock_phys_alloc_range(crash_size,
> + CRASH_ALIGN, CRASH_ALIGN,
> + CRASH_ADDR_HIGH_MAX);
> if (!crash_base) {
> pr_info("crashkernel reservation failed - No suitable area found.\n");
> return;
> @@ -517,19 +511,13 @@ static void __init reserve_crashkernel(void)
> } else {
> unsigned long long start;
>
> - start = memblock_find_in_range(crash_base,
> - crash_base + crash_size,
> - crash_size, 1 << 20);
> + start = memblock_phys_alloc_range(crash_size, SZ_1M, crash_base,
> + crash_base + crash_size);
> if (start != crash_base) {
> pr_info("crashkernel reservation failed - memory is in use.\n");
> return;
> }
> }
> - ret = memblock_reserve(crash_base, crash_size);
> - if (ret) {
> - pr_err("%s: Error reserving crashkernel memblock.\n", __func__);
> - return;
> - }
>
> if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) {
> memblock_free(crash_base, crash_size);
> --
> 2.26.2
>
