Re: [PATCH -next v3 2/2] docs: kdump: Update the crashkernel description for riscv
On 2023/4/7 6:02, Chen Jiahao wrote: > Now "crashkernel=" parameter on riscv has been updated to support > crashkernel=X,[high,low]. Through which we can reserve memory region > above/within 32bit addressible DMA zone. > > Here update the parameter description accordingly. Reviewed-by: Zhen Lei > > Signed-off-by: Chen Jiahao > --- > Documentation/admin-guide/kernel-parameters.txt | 15 --- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 54702bd488eb..41865aae9eaa 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -866,7 +866,7 @@ > memory region [offset, offset + size] for that kernel > image. If '@offset' is omitted, then a suitable offset > is selected automatically. > - [KNL, X86-64, ARM64] Select a region under 4G first, and > + [KNL, X86-64, ARM64, RISCV] Select a region under 4G > first, and > fall back to reserve region above 4G when '@offset' > hasn't been specified. > See Documentation/admin-guide/kdump/kdump.rst for > further details. > @@ -879,14 +879,14 @@ > Documentation/admin-guide/kdump/kdump.rst for an > example. > > crashkernel=size[KMG],high > - [KNL, X86-64, ARM64] range could be above 4G. Allow > kernel > - to allocate physical memory region from top, so could > - be above 4G if system have more than 4G ram installed. > - Otherwise memory region will be allocated below 4G, if > - available. > + [KNL, X86-64, ARM64, RISCV] range could be above 4G. > + Allow kernel to allocate physical memory region from > top, > + so could be above 4G if system have more than 4G ram > + installed. Otherwise memory region will be allocated > + below 4G, if available. > It will be ignored if crashkernel=X is specified. > crashkernel=size[KMG],low > - [KNL, X86-64, ARM64] range under 4G. When > crashkernel=X,high > + [KNL, X86-64, ARM64, RISCV] range under 4G. When > crashkernel=X,high > is passed, kernel could allocate physical memory region > above 4G, that cause second kernel crash on system > that require some amount of low memory, e.g. swiotlb > @@ -897,6 +897,7 @@ > size is platform dependent. > --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB) > --> arm64: 128MiB > + --> riscv: 128MiB > This one lets the user specify own low range under 4G > for second kernel instead. > 0: to disable low allocation. > -- Regards, Zhen Lei ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH -next v3 1/2] riscv: kdump: Implement crashkernel=X,[high,low]
On 2023/4/7 20:58, Leizhen (ThunderTown) wrote:
>
>
> On 2023/4/7 20:03, Simon Horman wrote:
>> On Fri, Apr 07, 2023 at 06:02:05AM +0800, Chen Jiahao wrote:
>>> On riscv, the current crash kernel allocation logic is trying to
>>> allocate within 32bit addressible memory region by default, if
>>> failed, try to allocate without 4G restriction.
>>>
>>> In need of saving DMA zone memory while allocating a relatively large
>>> crash kernel region, allocating the reserved memory top down in
>>> high memory, without overlapping the DMA zone, is a mature solution.
>>> Here introduce the parameter option crashkernel=X,[high,low].
>>>
>>> One can reserve the crash kernel from high memory above DMA zone range
>>> by explicitly passing "crashkernel=X,high"; or reserve a memory range
>>> below 4G with "crashkernel=X,low".
>>>
>>> Signed-off-by: Chen Jiahao
>>
>> ...
>>
>>> @@ -1180,14 +1206,37 @@ static void __init reserve_crashkernel(void)
>>> return;
>>> }
>>>
>>> - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
>>> + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
>>> _size, _base);
>>> - if (ret || !crash_size)
>>> + if (ret == -ENOENT) {
>>> + /*
>>> +* crashkernel=X,[high,low] can be specified or not, but
>>> +* invalid value is not allowed.
>>
>> nit: Perhaps something like this would be easier to correlate with the
>> code that follows:
>>
>> /* Fallback to crashkernel=X,[high,low] */
>
> The description "crashkernel=X,[high,low] can be specified or not" is not
> correct, because crashkernel=X,high must be specified when walking into this
> branch. So use Simon's comments or copy arm64's comments(it's written for
> parse_crashkernel_low()).
I rethink it a little bit, if it's relative to crashkernel=X[@offset],
that's also true.
Reviewed-by: Zhen Lei
>
>>
>>
>>> +*/
>>> + ret = parse_crashkernel_high(cmdline, 0, _size,
>>> _base);
>>> + if (ret || !crash_size)
>>> + return;
>>> +
>>> + /*
>>> +* crashkernel=Y,low is valid only when crashkernel=X,high
>>> +* is passed and high memory is reserved successful.
>>
>> nit: s/successful/successfully/
>
> Seems like the whole "and high memory is reserved successful" needs to be
> deleted.
> Only the dependency between the two boot options should be described here,
> regardless of whether their memory is successfully allocated.
>
>>
>>> +*/
>>> + ret = parse_crashkernel_low(cmdline, 0, _low_size,
>>> _base);
>>> + if (ret == -ENOENT)
>>> + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
>>> + else if (ret)
>>> + return;
>>> +
>>> + search_start = search_low_max;
>>> + } else if (ret || !crash_size) {
>>> + /* Invalid argument value specified */
>>> return;
>>> + }
>>
>> ...
>> .
>>
>
--
Regards,
Zhen Lei
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Re: [PATCH v5 2/2] x86/purgatory: Add linker script
Hi Ricardo,
Thanks for the patch! Please make sure to cc our mailing list
for llvm specific issues.
scripts/get_maintainer.pl should recommend it, or you can find it from
clangbuiltlinux.github.io. You can also ping me internally for
toolchain related issues.
Start of thread.
https://lore.kernel.org/lkml/20230321-kexec_clang16-v5-0-5563bf7c4...@chromium.org/
On Thu, Mar 30, 2023 at 9:00 AM Borislav Petkov wrote:
>
> On Thu, Mar 30, 2023 at 11:31:27AM -0400, Steven Rostedt wrote:
> > On Thu, 30 Mar 2023 17:18:26 +0200
> > Borislav Petkov wrote:
> >
> > > On Thu, Mar 30, 2023 at 11:15:23AM -0400, Steven Rostedt wrote:
> > > > > Make sure that the .text section is not divided in multiple
> > > > > overlapping
> > > > > sections. This is not supported by kexec_file.
Perhaps this is related to CrOS' use of AutoFDO creating .text.hot?
If so, it's probably more straightforward to straight up disable PGO
for kexec. See also:
commit bde971a83bbf ("KVM: arm64: nvhe: Fix build with profile optimization")
> > >
> > > And?
> > >
> > > What is the failure scenario? Why are you fixing it? Why do we care?
> > >
> > > This is way too laconic.
> > >
> >
> > Yeah, I think the change log in patch 1 needs to be in this patch too,
> > which gives better context.
>
> Just read it.
>
> Why did it work with clang version < 16?
I'll bet if we bisect llvm, we can spot what might have changed, which
may give us a clue on how to get the old behavior back; maybe without
the need for a linker script.
Ricardo, how did you verify that your fix was correct? Surely we can
check using command line utilities without needing a full blown kexec
setup? If you can share more info, I can bisect llvm quickly. If it
requires profile data, you'll need to share it, since CrOS engineers
still have not posted public documentation on AutoFDO as I have
repeatedly asked for.
>
> + toolchains ML.
>
> --
> Regards/Gruss,
> Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette
--
Thanks,
~Nick Desaulniers
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Re: [PATCH -next v3 1/2] riscv: kdump: Implement crashkernel=X,[high,low]
On 2023/4/7 20:03, Simon Horman wrote:
> On Fri, Apr 07, 2023 at 06:02:05AM +0800, Chen Jiahao wrote:
>> On riscv, the current crash kernel allocation logic is trying to
>> allocate within 32bit addressible memory region by default, if
>> failed, try to allocate without 4G restriction.
>>
>> In need of saving DMA zone memory while allocating a relatively large
>> crash kernel region, allocating the reserved memory top down in
>> high memory, without overlapping the DMA zone, is a mature solution.
>> Here introduce the parameter option crashkernel=X,[high,low].
>>
>> One can reserve the crash kernel from high memory above DMA zone range
>> by explicitly passing "crashkernel=X,high"; or reserve a memory range
>> below 4G with "crashkernel=X,low".
>>
>> Signed-off-by: Chen Jiahao
>
> ...
>
>> @@ -1180,14 +1206,37 @@ static void __init reserve_crashkernel(void)
>> return;
>> }
>>
>> -ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
>> +ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
>> _size, _base);
>> -if (ret || !crash_size)
>> +if (ret == -ENOENT) {
>> +/*
>> + * crashkernel=X,[high,low] can be specified or not, but
>> + * invalid value is not allowed.
>
> nit: Perhaps something like this would be easier to correlate with the
> code that follows:
>
> /* Fallback to crashkernel=X,[high,low] */
The description "crashkernel=X,[high,low] can be specified or not" is not
correct, because crashkernel=X,high must be specified when walking into this
branch. So use Simon's comments or copy arm64's comments(it's written for
parse_crashkernel_low()).
>
>
>> + */
>> +ret = parse_crashkernel_high(cmdline, 0, _size,
>> _base);
>> +if (ret || !crash_size)
>> +return;
>> +
>> +/*
>> + * crashkernel=Y,low is valid only when crashkernel=X,high
>> + * is passed and high memory is reserved successful.
>
> nit: s/successful/successfully/
Seems like the whole "and high memory is reserved successful" needs to be
deleted.
Only the dependency between the two boot options should be described here,
regardless of whether their memory is successfully allocated.
>
>> + */
>> +ret = parse_crashkernel_low(cmdline, 0, _low_size,
>> _base);
>> +if (ret == -ENOENT)
>> +crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
>> +else if (ret)
>> +return;
>> +
>> +search_start = search_low_max;
>> +} else if (ret || !crash_size) {
>> +/* Invalid argument value specified */
>> return;
>> +}
>
> ...
> .
>
--
Regards,
Zhen Lei
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Re: [PATCH -next v3 0/2] support allocating crashkernel above 4G explicitly on riscv
On Fri, Apr 07, 2023 at 06:02:04AM +0800, Chen Jiahao wrote: > On riscv, the current crash kernel allocation logic is trying to > allocate within 32bit addressible memory region by default, if > failed, try to allocate without 4G restriction. > > In need of saving DMA zone memory while allocating a relatively large > crash kernel region, allocating the reserved memory top down in > high memory, without overlapping the DMA zone, is a mature solution. > Hence this patchset introduces the parameter option crashkernel=X,[high,low]. > > One can reserve the crash kernel from high memory above DMA zone range > by explicitly passing "crashkernel=X,high"; or reserve a memory range > below 4G with "crashkernel=X,low". Besides, there are few rules need > to take notice: > 1. "crashkernel=X,[high,low]" will be ignored if "crashkernel=size" >is specified. > 2. "crashkernel=X,low" is valid only when "crashkernel=X,high" is passed >and there is enough memory to be allocated under 4G. > 3. When allocating crashkernel above 4G and no "crashkernel=X,low" is >specified, a 128M low memory will be allocated automatically for >swiotlb bounce buffer. > See Documentation/admin-guide/kernel-parameters.txt for more information. > > To verify loading the crashkernel, adapted kexec-tools is attached below: > https://github.com/chenjh005/kexec-tools/tree/build-test-riscv-v2 Are you planning to submit the kexec-tools patches too? ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH -next v3 2/2] docs: kdump: Update the crashkernel description for riscv
On Fri, Apr 07, 2023 at 06:02:06AM +0800, Chen Jiahao wrote: > Now "crashkernel=" parameter on riscv has been updated to support > crashkernel=X,[high,low]. Through which we can reserve memory region > above/within 32bit addressible DMA zone. > > Here update the parameter description accordingly. > > Signed-off-by: Chen Jiahao Reviewed-by: Simon Horman ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH -next v3 1/2] riscv: kdump: Implement crashkernel=X,[high,low]
On Fri, Apr 07, 2023 at 06:02:05AM +0800, Chen Jiahao wrote:
> On riscv, the current crash kernel allocation logic is trying to
> allocate within 32bit addressible memory region by default, if
> failed, try to allocate without 4G restriction.
>
> In need of saving DMA zone memory while allocating a relatively large
> crash kernel region, allocating the reserved memory top down in
> high memory, without overlapping the DMA zone, is a mature solution.
> Here introduce the parameter option crashkernel=X,[high,low].
>
> One can reserve the crash kernel from high memory above DMA zone range
> by explicitly passing "crashkernel=X,high"; or reserve a memory range
> below 4G with "crashkernel=X,low".
>
> Signed-off-by: Chen Jiahao
...
> @@ -1180,14 +1206,37 @@ static void __init reserve_crashkernel(void)
> return;
> }
>
> - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
> + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
> _size, _base);
> - if (ret || !crash_size)
> + if (ret == -ENOENT) {
> + /*
> + * crashkernel=X,[high,low] can be specified or not, but
> + * invalid value is not allowed.
nit: Perhaps something like this would be easier to correlate with the
code that follows:
/* Fallback to crashkernel=X,[high,low] */
> + */
> + ret = parse_crashkernel_high(cmdline, 0, _size,
> _base);
> + if (ret || !crash_size)
> + return;
> +
> + /*
> + * crashkernel=Y,low is valid only when crashkernel=X,high
> + * is passed and high memory is reserved successful.
nit: s/successful/successfully/
> + */
> + ret = parse_crashkernel_low(cmdline, 0, _low_size,
> _base);
> + if (ret == -ENOENT)
> + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
> + else if (ret)
> + return;
> +
> + search_start = search_low_max;
> + } else if (ret || !crash_size) {
> + /* Invalid argument value specified */
> return;
> + }
...
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Re: [PATCH -next v3 1/2] riscv: kdump: Implement crashkernel=X,[high,low]
On Fri, Apr 07, 2023 at 05:06:24PM +0800, Guo Ren wrote: > On Thu, Apr 6, 2023 at 10:06 PM Chen Jiahao wrote: > > > > On riscv, the current crash kernel allocation logic is trying to > > allocate within 32bit addressible memory region by default, if > > failed, try to allocate without 4G restriction. > > > > In need of saving DMA zone memory while allocating a relatively large > > crash kernel region, allocating the reserved memory top down in > > high memory, without overlapping the DMA zone, is a mature solution. > > Here introduce the parameter option crashkernel=X,[high,low]. > > > > One can reserve the crash kernel from high memory above DMA zone range > > by explicitly passing "crashkernel=X,high"; or reserve a memory range > > below 4G with "crashkernel=X,low". > Asked-by: Guo Ren Perhaps 'Acked-by' :) ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH -next v3 1/2] riscv: kdump: Implement crashkernel=X,[high,low]
On Thu, Apr 6, 2023 at 10:06 PM Chen Jiahao wrote:
>
> On riscv, the current crash kernel allocation logic is trying to
> allocate within 32bit addressible memory region by default, if
> failed, try to allocate without 4G restriction.
>
> In need of saving DMA zone memory while allocating a relatively large
> crash kernel region, allocating the reserved memory top down in
> high memory, without overlapping the DMA zone, is a mature solution.
> Here introduce the parameter option crashkernel=X,[high,low].
>
> One can reserve the crash kernel from high memory above DMA zone range
> by explicitly passing "crashkernel=X,high"; or reserve a memory range
> below 4G with "crashkernel=X,low".
Asked-by: Guo Ren
>
> Signed-off-by: Chen Jiahao
> ---
> arch/riscv/kernel/setup.c | 5 +++
> arch/riscv/mm/init.c | 74 ---
> 2 files changed, 74 insertions(+), 5 deletions(-)
>
> diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> index 5d3184cbf518..ea84e5047c23 100644
> --- a/arch/riscv/kernel/setup.c
> +++ b/arch/riscv/kernel/setup.c
> @@ -176,6 +176,11 @@ static void __init init_resources(void)
> if (ret < 0)
> goto error;
> }
> + if (crashk_low_res.start != crashk_low_res.end) {
> + ret = add_resource(_resource, _low_res);
> + if (ret < 0)
> + goto error;
> + }
> #endif
>
> #ifdef CONFIG_CRASH_DUMP
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 478d6763a01a..b5b457193423 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -1152,6 +1152,28 @@ static inline void setup_vm_final(void)
> }
> #endif /* CONFIG_MMU */
>
> +/* Reserve 128M low memory by default for swiotlb buffer */
> +#define DEFAULT_CRASH_KERNEL_LOW_SIZE (128UL << 20)
> +
> +static int __init reserve_crashkernel_low(unsigned long long low_size)
> +{
> + unsigned long long low_base;
> +
> + low_base = memblock_phys_alloc_range(low_size, PMD_SIZE, 0,
> dma32_phys_limit);
> + if (!low_base) {
> + pr_err("cannot allocate crashkernel low memory
> (size:0x%llx).\n", low_size);
> + return -ENOMEM;
> + }
> +
> + pr_info("crashkernel low memory reserved: 0x%016llx - 0x%016llx (%lld
> MB)\n",
> + low_base, low_base + low_size, low_size >> 20);
> +
> + crashk_low_res.start = low_base;
> + crashk_low_res.end = low_base + low_size - 1;
> +
> + return 0;
> +}
> +
> /*
> * reserve_crashkernel() - reserves memory for crash kernel
> *
> @@ -1163,8 +1185,12 @@ static void __init reserve_crashkernel(void)
> {
> unsigned long long crash_base = 0;
> unsigned long long crash_size = 0;
> + unsigned long long crash_low_size = 0;
> unsigned long search_start = memblock_start_of_DRAM();
> unsigned long search_end = memblock_end_of_DRAM();
> + unsigned long search_low_max = (unsigned long)dma32_phys_limit;
> + char *cmdline = boot_command_line;
> + bool fixed_base = false;
>
> int ret = 0;
>
> @@ -1180,14 +1206,37 @@ static void __init reserve_crashkernel(void)
> return;
> }
>
> - ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
> + ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
> _size, _base);
> - if (ret || !crash_size)
> + if (ret == -ENOENT) {
> + /*
> +* crashkernel=X,[high,low] can be specified or not, but
> +* invalid value is not allowed.
> +*/
> + ret = parse_crashkernel_high(cmdline, 0, _size,
> _base);
> + if (ret || !crash_size)
> + return;
> +
> + /*
> +* crashkernel=Y,low is valid only when crashkernel=X,high
> +* is passed and high memory is reserved successful.
> +*/
> + ret = parse_crashkernel_low(cmdline, 0, _low_size,
> _base);
> + if (ret == -ENOENT)
> + crash_low_size = DEFAULT_CRASH_KERNEL_LOW_SIZE;
> + else if (ret)
> + return;
> +
> + search_start = search_low_max;
> + } else if (ret || !crash_size) {
> + /* Invalid argument value specified */
> return;
> + }
>
> crash_size = PAGE_ALIGN(crash_size);
>
> if (crash_base) {
> + fixed_base = true;
> search_start = crash_base;
> search_end = crash_base + crash_size;
> }
> @@ -1201,16 +1250,31 @@ static void __init reserve_crashkernel(void)
> */
> crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
>search_start,
> - min(search_end,
Re: [PATCH -next v3 2/2] docs: kdump: Update the crashkernel description for riscv
Reviewed-by: Guo Ren On Thu, Apr 6, 2023 at 10:05 PM Chen Jiahao wrote: > > Now "crashkernel=" parameter on riscv has been updated to support > crashkernel=X,[high,low]. Through which we can reserve memory region > above/within 32bit addressible DMA zone. > > Here update the parameter description accordingly. > > Signed-off-by: Chen Jiahao > --- > Documentation/admin-guide/kernel-parameters.txt | 15 --- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 54702bd488eb..41865aae9eaa 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -866,7 +866,7 @@ > memory region [offset, offset + size] for that kernel > image. If '@offset' is omitted, then a suitable offset > is selected automatically. > - [KNL, X86-64, ARM64] Select a region under 4G first, > and > + [KNL, X86-64, ARM64, RISCV] Select a region under 4G > first, and > fall back to reserve region above 4G when '@offset' > hasn't been specified. > See Documentation/admin-guide/kdump/kdump.rst for > further details. > @@ -879,14 +879,14 @@ > Documentation/admin-guide/kdump/kdump.rst for an > example. > > crashkernel=size[KMG],high > - [KNL, X86-64, ARM64] range could be above 4G. Allow > kernel > - to allocate physical memory region from top, so could > - be above 4G if system have more than 4G ram installed. > - Otherwise memory region will be allocated below 4G, if > - available. > + [KNL, X86-64, ARM64, RISCV] range could be above 4G. > + Allow kernel to allocate physical memory region from > top, > + so could be above 4G if system have more than 4G ram > + installed. Otherwise memory region will be allocated > + below 4G, if available. > It will be ignored if crashkernel=X is specified. > crashkernel=size[KMG],low > - [KNL, X86-64, ARM64] range under 4G. When > crashkernel=X,high > + [KNL, X86-64, ARM64, RISCV] range under 4G. When > crashkernel=X,high > is passed, kernel could allocate physical memory > region > above 4G, that cause second kernel crash on system > that require some amount of low memory, e.g. swiotlb > @@ -897,6 +897,7 @@ > size is platform dependent. > --> x86: max(swiotlb_size_or_default() + 8MiB, > 256MiB) > --> arm64: 128MiB > + --> riscv: 128MiB > This one lets the user specify own low range under 4G > for second kernel instead. > 0: to disable low allocation. > -- > 2.31.1 > -- Best Regards Guo Ren ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
