Hi Baoquan, On 2020/9/18 15:25, Baoquan He wrote: > Hi, > > On 09/07/20 at 09:47pm, Chen Zhou wrote: >> To make the functions reserve_crashkernel[_low]() as generic, >> replace some hard-coded numbers with macro CRASH_ADDR_LOW_MAX. >> >> Signed-off-by: Chen Zhou <chenzhou10@xxxxxxxxxx> >> --- >> arch/x86/kernel/setup.c | 11 ++++++----- >> 1 file changed, 6 insertions(+), 5 deletions(-) >> >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> index d7fd90c52dae..71a6a6e7ca5b 100644 >> --- a/arch/x86/kernel/setup.c >> +++ b/arch/x86/kernel/setup.c >> @@ -430,7 +430,7 @@ static int __init reserve_crashkernel_low(void) >> unsigned long total_low_mem; >> int ret; >> >> - total_low_mem = memblock_mem_size(1UL << (32 - PAGE_SHIFT)); >> + total_low_mem = memblock_mem_size(CRASH_ADDR_LOW_MAX >> PAGE_SHIFT); > Just note that the replacement has been done in another patch from Mike > Rapoport, partially. He seems to have done reserve_crashkernel_low() > part, there's one left in reserve_crashkernel(), you might want to check > that. > > Mike's patch which is from a patchset has been merged into Andrew's next > tree. > > commit 6e50f7672ffa362e9bd4bc0c0d2524ed872828c5 > Author: Mike Rapoport <rppt@xxxxxxxxxxxxx> > Date: Wed Aug 26 15:22:32 2020 +1000 > > x86/setup: simplify reserve_crashkernel() Yeah, the function reserve_crashkernel() has been changed in the next tree. Thanks for your review and reminder. Thanks, Chen Zhou > >> >> /* crashkernel=Y,low */ >> ret = parse_crashkernel_low(boot_command_line, total_low_mem, &low_size, &base); >> @@ -451,7 +451,7 @@ static int __init reserve_crashkernel_low(void) >> return 0; >> } >> >> - low_base = memblock_find_in_range(CRASH_ALIGN, 1ULL << 32, low_size, CRASH_ALIGN); >> + low_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_LOW_MAX, low_size, CRASH_ALIGN); >> if (!low_base) { >> pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", >> (unsigned long)(low_size >> 20)); >> @@ -504,8 +504,9 @@ static void __init reserve_crashkernel(void) >> if (!crash_base) { >> /* >> * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, >> - * crashkernel=x,high reserves memory over 4G, also allocates >> - * 256M extra low memory for DMA buffers and swiotlb. >> + * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, >> + * also allocates 256M extra low memory for DMA buffers >> + * and swiotlb. >> * But the extra memory is not required for all machines. >> * So try low memory first and fall back to high memory >> * unless "crashkernel=size[KMG],high" is specified. >> @@ -539,7 +540,7 @@ static void __init reserve_crashkernel(void) >> return; >> } >> >> - if (crash_base >= (1ULL << 32) && reserve_crashkernel_low()) { >> + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> memblock_free(crash_base, crash_size); >> return; >> } >> -- >> 2.20.1 >> > . >