For analyzing memory blocks we can either use the memblock=debug command
line argument which creates massive output or a debug file system.
Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
/sys/kernel/debug/memblock to analyze memory blocks. The
same is already done for arm, arm64, mips, powerpc.
The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
Signed-off-by: Heinrich Schuchardt <[email protected]>
---
arch/riscv/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 4f7b70ae7c31..a6e57614c3fd 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -31,6 +31,7 @@ config RISCV
select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
+ select ARCH_KEEP_MEMBLOCK
select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
select ARCH_SUPPORTS_HUGETLBFS if MMU
--
2.30.2
On 2021/8/16 22:47, Heinrich Schuchardt wrote:
> For analyzing memory blocks we can either use the memblock=debug command
> line argument which creates massive output or a debug file system.
>
> Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
> /sys/kernel/debug/memblock to analyze memory blocks. The
> same is already done for arm, arm64, mips, powerpc.
>
> The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
Hi，for riscv, it don't use memblock(eg, no provide pfn_valid to use
memblock),
we could call memblock_discard() to discard memblock private memory to save
some memory, right? So I think we don't need this config for now.
>
> Signed-off-by: Heinrich Schuchardt <[email protected]>
> ---
> arch/riscv/Kconfig | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 4f7b70ae7c31..a6e57614c3fd 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -31,6 +31,7 @@ config RISCV
> select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
> select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> + select ARCH_KEEP_MEMBLOCK
> select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
> select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
> select ARCH_SUPPORTS_HUGETLBFS if MMU
On 8/16/21 5:30 PM, Kefeng Wang wrote:
>
> On 2021/8/16 22:47, Heinrich Schuchardt wrote:
>> For analyzing memory blocks we can either use the memblock=debug command
>> line argument which creates massive output or a debug file system.
>>
>> Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
>> /sys/kernel/debug/memblock to analyze memory blocks. The
>> same is already done for arm, arm64, mips, powerpc.
>>
>> The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
>
> Hi，for riscv, it don't use memblock(eg, no provide pfn_valid to use
> memblock),
>
> we could call memblock_discard() to discard memblock private memory to save
>
> some memory, right? So I think we don't need this config for now.
What do you mean by "it don't use memblock?
If you boot the HiFive Unmatched with memblock=debug you will see output
like the one below. This is the information that you can see in the
debug file system if CONFIG_DEBUG_FS and CONFIG_ARCH_KEEP_MEMBLOCK will
be enabled.
[ 0.000000] MEMBLOCK configuration:
[ 0.000000] memory size = 0x00000003ffe00000 reserved size =
0x000000001290fb70
[ 0.000000] memory.cnt = 0x25
[ 0.000000] memory[0x0] [0x0000000080200000-0x00000000fe6e2fff],
0x000000007e4e3000 bytes flags: 0x0
[ 0.000000] memory[0x1] [0x00000000fe6e3000-0x00000000fe6e5fff],
0x0000000000003000 bytes flags: 0x4
[ 0.000000] memory[0x2] [0x00000000fe6e6000-0x00000000fe709fff],
0x0000000000024000 bytes flags: 0x0
[ 0.000000] memory[0x3] [0x00000000fe70a000-0x00000000fe70bfff],
0x0000000000002000 bytes flags: 0x4
[ 0.000000] memory[0x4] [0x00000000fe70c000-0x00000000fe70ffff],
0x0000000000004000 bytes flags: 0x0
[ 0.000000] memory[0x5] [0x00000000fe710000-0x00000000fe710fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x6] [0x00000000fe711000-0x00000000fe712fff],
0x0000000000002000 bytes flags: 0x0
[ 0.000000] memory[0x7] [0x00000000fe713000-0x00000000fe716fff],
0x0000000000004000 bytes flags: 0x4
[ 0.000000] memory[0x8] [0x00000000fe717000-0x00000000fe717fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x9] [0x00000000fe718000-0x00000000fe71cfff],
0x0000000000005000 bytes flags: 0x4
[ 0.000000] memory[0xa] [0x00000000fe71d000-0x00000000fe71dfff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0xb] [0x00000000fe71e000-0x00000000fe71efff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0xc] [0x00000000fe71f000-0x00000000fe71ffff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0xd] [0x00000000fe720000-0x00000000fe720fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0xe] [0x00000000fe721000-0x00000000fe721fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0xf] [0x00000000fe722000-0x00000000fe722fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x10] [0x00000000fe723000-0x00000000fe723fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x11] [0x00000000fe724000-0x00000000fe724fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x12] [0x00000000fe725000-0x00000000fe725fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x13] [0x00000000fe726000-0x00000000fe726fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x14] [0x00000000fe727000-0x00000000fe728fff],
0x0000000000002000 bytes flags: 0x0
[ 0.000000] memory[0x15] [0x00000000fe729000-0x00000000fe729fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x16] [0x00000000fe72a000-0x00000000fe72afff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x17] [0x00000000fe72b000-0x00000000fe72cfff],
0x0000000000002000 bytes flags: 0x4
[ 0.000000] memory[0x18] [0x00000000fe72d000-0x00000000fe72dfff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x19] [0x00000000fe72e000-0x00000000fe72efff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x1a] [0x00000000fe72f000-0x00000000fe72ffff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x1b] [0x00000000fe730000-0x00000000fe730fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x1c] [0x00000000fe731000-0x00000000fe731fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x1d] [0x00000000fe732000-0x00000000fe732fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x1e] [0x00000000fe733000-0x00000000fe733fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] memory[0x1f] [0x00000000fe734000-0x00000000fe734fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x20] [0x00000000fe735000-0x00000000fe736fff],
0x0000000000002000 bytes flags: 0x0
[ 0.000000] memory[0x21] [0x00000000fe737000-0x00000000fe737fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x22] [0x00000000fe738000-0x00000000fff60fff],
0x0000000001829000 bytes flags: 0x0
[ 0.000000] memory[0x23] [0x00000000fff61000-0x00000000fff61fff],
0x0000000000001000 bytes flags: 0x4
[ 0.000000] memory[0x24] [0x00000000fff62000-0x000000047fffffff],
0x000000038009e000 bytes flags: 0x0
[ 0.000000] reserved.cnt = 0xd
[ 0.000000] reserved[0x0] [0x0000000080000000-0x000000008007ffff],
0x0000000000080000 bytes flags: 0x0
[ 0.000000] reserved[0x1] [0x0000000080200000-0x00000000815fffff],
0x0000000001400000 bytes flags: 0x0
[ 0.000000] reserved[0x2] [0x0000000087f00000-0x0000000087f05fff],
0x0000000000006000 bytes flags: 0x0
[ 0.000000] reserved[0x3] [0x00000000db0a2000-0x00000000db0a48b4],
0x00000000000028b5 bytes flags: 0x0
[ 0.000000] reserved[0x4] [0x00000000db2a2000-0x00000000dc709fff],
0x0000000001468000 bytes flags: 0x0
[ 0.000000] reserved[0x5] [0x00000000fe701000-0x00000000fe701fff],
0x0000000000001000 bytes flags: 0x0
[ 0.000000] reserved[0x6] [0x00000000fe704040-0x00000000fe70404f],
0x0000000000000010 bytes flags: 0x0
[ 0.000000] reserved[0x7] [0x000000046ffe1d40-0x000000047dfe253f],
0x000000000e000800 bytes flags: 0x0
[ 0.000000] reserved[0x8] [0x000000047dfe2548-0x000000047dfe2578],
0x0000000000000031 bytes flags: 0x0
[ 0.000000] reserved[0x9] [0x000000047dfe2580-0x000000047dfe25ae],
0x000000000000002f bytes flags: 0x0
[ 0.000000] reserved[0xa] [0x000000047dfe25b0-0x000000047dfe25de],
0x000000000000002f bytes flags: 0x0
[ 0.000000] reserved[0xb] [0x000000047dfe25e0-0x000000047dfefffb],
0x000000000000da1c bytes flags: 0x0
[ 0.000000] reserved[0xc] [0x000000047dff0000-0x000000047fffffff],
0x0000000002010000 bytes flags: 0x0
Best regards
Heinrich
>
>>
>> Signed-off-by: Heinrich Schuchardt <[email protected]>
>> ---
>> arch/riscv/Kconfig | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 4f7b70ae7c31..a6e57614c3fd 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -31,6 +31,7 @@ config RISCV
>> select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
>> select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
>> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>> + select ARCH_KEEP_MEMBLOCK
>> select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
>> select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>> select ARCH_SUPPORTS_HUGETLBFS if MMU
On 2021/8/16 23:52, Heinrich Schuchardt wrote:
> On 8/16/21 5:30 PM, Kefeng Wang wrote:
>>
>> On 2021/8/16 22:47, Heinrich Schuchardt wrote:
>>> For analyzing memory blocks we can either use the memblock=debug
>>> command
>>> line argument which creates massive output or a debug file system.
>>>
>>> Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
>>> /sys/kernel/debug/memblock to analyze memory blocks. The
>>> same is already done for arm, arm64, mips, powerpc.
>>>
>>> The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
>>
>> Hi，for riscv, it don't use memblock(eg, no provide pfn_valid to use
>> memblock),
>>
>> we could call memblock_discard() to discard memblock private memory
>> to save
>>
>> some memory, right? So I think we don't need this config for now.
>
> What do you mean by "it don't use memblock?
Sorry, it should be "the riscv don't use memblock after the page
allocator is initialized"
Hi Heinrich,
On Mon, Aug 16, 2021 at 05:52:11PM +0200, Heinrich Schuchardt wrote:
> On 8/16/21 5:30 PM, Kefeng Wang wrote:
> >
> > On 2021/8/16 22:47, Heinrich Schuchardt wrote:
> > > For analyzing memory blocks we can either use the memblock=debug command
> > > line argument which creates massive output or a debug file system.
> > >
> > > Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
> > > /sys/kernel/debug/memblock to analyze memory blocks. The
> > > same is already done for arm, arm64, mips, powerpc.
> > >
> > > The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
> >
> > Hi，for riscv, it don't use memblock(eg, no provide pfn_valid to use
> > memblock),
> >
> > we could call memblock_discard() to discard memblock private memory to save
> >
> > some memory, right? So I think we don't need this config for now.
>
> What do you mean by "it don't use memblock?
>
> If you boot the HiFive Unmatched with memblock=debug you will see output
> like the one below. This is the information that you can see in the debug
> file system if CONFIG_DEBUG_FS and CONFIG_ARCH_KEEP_MEMBLOCK will be
> enabled.
Indeed having this info in debugfs is more convenient, but it comes with a
cost of several kilobytes of code and data for *every* riscv build.
Why parsing "memblock=debug" output is not enough?
What is the use-case that justifies the costs associated with having the
debugfs entries?
> [ 0.000000] MEMBLOCK configuration:
> [ 0.000000] memory size = 0x00000003ffe00000 reserved size =
> 0x000000001290fb70
> [ 0.000000] memory.cnt = 0x25
BTW, it seems that the memory allocation by firmware is, well, suboptimal
and begs for fixes. I don't see why all these NOMAP areas cannot be put in
one contiguous chunk. I doubt they need to be NOMAP at all, but mysterious
the ways of ACPI.
> [ 0.000000] memory[0x0] [0x0000000080200000-0x00000000fe6e2fff],
> 0x000000007e4e3000 bytes flags: 0x0
> [ 0.000000] memory[0x1] [0x00000000fe6e3000-0x00000000fe6e5fff],
> 0x0000000000003000 bytes flags: 0x4
> [ 0.000000] memory[0x2] [0x00000000fe6e6000-0x00000000fe709fff],
> 0x0000000000024000 bytes flags: 0x0
> [ 0.000000] memory[0x3] [0x00000000fe70a000-0x00000000fe70bfff],
> 0x0000000000002000 bytes flags: 0x4
> [ 0.000000] memory[0x4] [0x00000000fe70c000-0x00000000fe70ffff],
> 0x0000000000004000 bytes flags: 0x0
> [ 0.000000] memory[0x5] [0x00000000fe710000-0x00000000fe710fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x6] [0x00000000fe711000-0x00000000fe712fff],
> 0x0000000000002000 bytes flags: 0x0
> [ 0.000000] memory[0x7] [0x00000000fe713000-0x00000000fe716fff],
> 0x0000000000004000 bytes flags: 0x4
> [ 0.000000] memory[0x8] [0x00000000fe717000-0x00000000fe717fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x9] [0x00000000fe718000-0x00000000fe71cfff],
> 0x0000000000005000 bytes flags: 0x4
> [ 0.000000] memory[0xa] [0x00000000fe71d000-0x00000000fe71dfff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0xb] [0x00000000fe71e000-0x00000000fe71efff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0xc] [0x00000000fe71f000-0x00000000fe71ffff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0xd] [0x00000000fe720000-0x00000000fe720fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0xe] [0x00000000fe721000-0x00000000fe721fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0xf] [0x00000000fe722000-0x00000000fe722fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x10] [0x00000000fe723000-0x00000000fe723fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x11] [0x00000000fe724000-0x00000000fe724fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x12] [0x00000000fe725000-0x00000000fe725fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x13] [0x00000000fe726000-0x00000000fe726fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x14] [0x00000000fe727000-0x00000000fe728fff],
> 0x0000000000002000 bytes flags: 0x0
> [ 0.000000] memory[0x15] [0x00000000fe729000-0x00000000fe729fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x16] [0x00000000fe72a000-0x00000000fe72afff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x17] [0x00000000fe72b000-0x00000000fe72cfff],
> 0x0000000000002000 bytes flags: 0x4
> [ 0.000000] memory[0x18] [0x00000000fe72d000-0x00000000fe72dfff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x19] [0x00000000fe72e000-0x00000000fe72efff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x1a] [0x00000000fe72f000-0x00000000fe72ffff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x1b] [0x00000000fe730000-0x00000000fe730fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x1c] [0x00000000fe731000-0x00000000fe731fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x1d] [0x00000000fe732000-0x00000000fe732fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x1e] [0x00000000fe733000-0x00000000fe733fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] memory[0x1f] [0x00000000fe734000-0x00000000fe734fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x20] [0x00000000fe735000-0x00000000fe736fff],
> 0x0000000000002000 bytes flags: 0x0
> [ 0.000000] memory[0x21] [0x00000000fe737000-0x00000000fe737fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x22] [0x00000000fe738000-0x00000000fff60fff],
> 0x0000000001829000 bytes flags: 0x0
> [ 0.000000] memory[0x23] [0x00000000fff61000-0x00000000fff61fff],
> 0x0000000000001000 bytes flags: 0x4
> [ 0.000000] memory[0x24] [0x00000000fff62000-0x000000047fffffff],
> 0x000000038009e000 bytes flags: 0x0
> [ 0.000000] reserved.cnt = 0xd
> [ 0.000000] reserved[0x0] [0x0000000080000000-0x000000008007ffff],
> 0x0000000000080000 bytes flags: 0x0
> [ 0.000000] reserved[0x1] [0x0000000080200000-0x00000000815fffff],
> 0x0000000001400000 bytes flags: 0x0
> [ 0.000000] reserved[0x2] [0x0000000087f00000-0x0000000087f05fff],
> 0x0000000000006000 bytes flags: 0x0
> [ 0.000000] reserved[0x3] [0x00000000db0a2000-0x00000000db0a48b4],
> 0x00000000000028b5 bytes flags: 0x0
> [ 0.000000] reserved[0x4] [0x00000000db2a2000-0x00000000dc709fff],
> 0x0000000001468000 bytes flags: 0x0
> [ 0.000000] reserved[0x5] [0x00000000fe701000-0x00000000fe701fff],
> 0x0000000000001000 bytes flags: 0x0
> [ 0.000000] reserved[0x6] [0x00000000fe704040-0x00000000fe70404f],
> 0x0000000000000010 bytes flags: 0x0
> [ 0.000000] reserved[0x7] [0x000000046ffe1d40-0x000000047dfe253f],
> 0x000000000e000800 bytes flags: 0x0
> [ 0.000000] reserved[0x8] [0x000000047dfe2548-0x000000047dfe2578],
> 0x0000000000000031 bytes flags: 0x0
> [ 0.000000] reserved[0x9] [0x000000047dfe2580-0x000000047dfe25ae],
> 0x000000000000002f bytes flags: 0x0
> [ 0.000000] reserved[0xa] [0x000000047dfe25b0-0x000000047dfe25de],
> 0x000000000000002f bytes flags: 0x0
> [ 0.000000] reserved[0xb] [0x000000047dfe25e0-0x000000047dfefffb],
> 0x000000000000da1c bytes flags: 0x0
> [ 0.000000] reserved[0xc] [0x000000047dff0000-0x000000047fffffff],
> 0x0000000002010000 bytes flags: 0x0
>
> Best regards
>
> Heinrich
>
> >
> > >
> > > Signed-off-by: Heinrich Schuchardt <[email protected]>
> > > ---
> > > arch/riscv/Kconfig | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > > index 4f7b70ae7c31..a6e57614c3fd 100644
> > > --- a/arch/riscv/Kconfig
> > > +++ b/arch/riscv/Kconfig
> > > @@ -31,6 +31,7 @@ config RISCV
> > > select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
> > > select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
> > > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> > > + select ARCH_KEEP_MEMBLOCK
> > > select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
> > > select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
> > > select ARCH_SUPPORTS_HUGETLBFS if MMU
>
>
> _______________________________________________
> linux-riscv mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-riscv
--
Sincerely yours,
Mike.
On Mon, 16 Aug 2021 11:50:26 PDT (-0700), [email protected] wrote:
> Hi Heinrich,
>
> On Mon, Aug 16, 2021 at 05:52:11PM +0200, Heinrich Schuchardt wrote:
>> On 8/16/21 5:30 PM, Kefeng Wang wrote:
>> >
>> > On 2021/8/16 22:47, Heinrich Schuchardt wrote:
>> > > For analyzing memory blocks we can either use the memblock=debug command
>> > > line argument which creates massive output or a debug file system.
>> > >
>> > > Select CONFIG_ARCH_KEEP_MEMBLOCK to provide a debugfs at
>> > > /sys/kernel/debug/memblock to analyze memory blocks. The
>> > > same is already done for arm, arm64, mips, powerpc.
>> > >
>> > > The actual provisioning of the file system depends on CONFIG_DEBUG_FS.
>> >
>> > Hi，for riscv, it don't use memblock(eg, no provide pfn_valid to use
>> > memblock),
>> >
>> > we could call memblock_discard() to discard memblock private memory to save
>> >
>> > some memory, right? So I think we don't need this config for now.
>>
>> What do you mean by "it don't use memblock?
>>
>> If you boot the HiFive Unmatched with memblock=debug you will see output
>> like the one below. This is the information that you can see in the debug
>> file system if CONFIG_DEBUG_FS and CONFIG_ARCH_KEEP_MEMBLOCK will be
>> enabled.
>
> Indeed having this info in debugfs is more convenient, but it comes with a
> cost of several kilobytes of code and data for *every* riscv build.
>
> Why parsing "memblock=debug" output is not enough?
> What is the use-case that justifies the costs associated with having the
> debugfs entries?
If someone can provide a use case I'm happy to look at how to enable it.
Otherwise I think we should just stick with the standard way of doing
things, which according to 350e88bad496 ("mm: memblock: make keeping
memblock memory opt-in rather than opt-out") seems to be that
ARCH_KEEP_MEMBLOCK is for ports that need that information, not just
those that pass it through to userspace.
>> [ 0.000000] MEMBLOCK configuration:
>> [ 0.000000] memory size = 0x00000003ffe00000 reserved size =
>> 0x000000001290fb70
>> [ 0.000000] memory.cnt = 0x25
>
> BTW, it seems that the memory allocation by firmware is, well, suboptimal
> and begs for fixes. I don't see why all these NOMAP areas cannot be put in
> one contiguous chunk. I doubt they need to be NOMAP at all, but mysterious
> the ways of ACPI.
We talked about this a bit in IRC and another thread, but it looks like
this mess has ended up in the specs. From my reading that was likely
the result of a blind copy/paste from some other architecture, but it's
in a released spec so it's cannon and I'm not really interested in
trying to change it as I'm tired of getting yelled at by the foundation
folks.
>> [ 0.000000] memory[0x0] [0x0000000080200000-0x00000000fe6e2fff],
>> 0x000000007e4e3000 bytes flags: 0x0
>> [ 0.000000] memory[0x1] [0x00000000fe6e3000-0x00000000fe6e5fff],
>> 0x0000000000003000 bytes flags: 0x4
>> [ 0.000000] memory[0x2] [0x00000000fe6e6000-0x00000000fe709fff],
>> 0x0000000000024000 bytes flags: 0x0
>> [ 0.000000] memory[0x3] [0x00000000fe70a000-0x00000000fe70bfff],
>> 0x0000000000002000 bytes flags: 0x4
>> [ 0.000000] memory[0x4] [0x00000000fe70c000-0x00000000fe70ffff],
>> 0x0000000000004000 bytes flags: 0x0
>> [ 0.000000] memory[0x5] [0x00000000fe710000-0x00000000fe710fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x6] [0x00000000fe711000-0x00000000fe712fff],
>> 0x0000000000002000 bytes flags: 0x0
>> [ 0.000000] memory[0x7] [0x00000000fe713000-0x00000000fe716fff],
>> 0x0000000000004000 bytes flags: 0x4
>> [ 0.000000] memory[0x8] [0x00000000fe717000-0x00000000fe717fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x9] [0x00000000fe718000-0x00000000fe71cfff],
>> 0x0000000000005000 bytes flags: 0x4
>> [ 0.000000] memory[0xa] [0x00000000fe71d000-0x00000000fe71dfff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0xb] [0x00000000fe71e000-0x00000000fe71efff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0xc] [0x00000000fe71f000-0x00000000fe71ffff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0xd] [0x00000000fe720000-0x00000000fe720fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0xe] [0x00000000fe721000-0x00000000fe721fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0xf] [0x00000000fe722000-0x00000000fe722fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x10] [0x00000000fe723000-0x00000000fe723fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x11] [0x00000000fe724000-0x00000000fe724fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x12] [0x00000000fe725000-0x00000000fe725fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x13] [0x00000000fe726000-0x00000000fe726fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x14] [0x00000000fe727000-0x00000000fe728fff],
>> 0x0000000000002000 bytes flags: 0x0
>> [ 0.000000] memory[0x15] [0x00000000fe729000-0x00000000fe729fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x16] [0x00000000fe72a000-0x00000000fe72afff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x17] [0x00000000fe72b000-0x00000000fe72cfff],
>> 0x0000000000002000 bytes flags: 0x4
>> [ 0.000000] memory[0x18] [0x00000000fe72d000-0x00000000fe72dfff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x19] [0x00000000fe72e000-0x00000000fe72efff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x1a] [0x00000000fe72f000-0x00000000fe72ffff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x1b] [0x00000000fe730000-0x00000000fe730fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x1c] [0x00000000fe731000-0x00000000fe731fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x1d] [0x00000000fe732000-0x00000000fe732fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x1e] [0x00000000fe733000-0x00000000fe733fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] memory[0x1f] [0x00000000fe734000-0x00000000fe734fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x20] [0x00000000fe735000-0x00000000fe736fff],
>> 0x0000000000002000 bytes flags: 0x0
>> [ 0.000000] memory[0x21] [0x00000000fe737000-0x00000000fe737fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x22] [0x00000000fe738000-0x00000000fff60fff],
>> 0x0000000001829000 bytes flags: 0x0
>> [ 0.000000] memory[0x23] [0x00000000fff61000-0x00000000fff61fff],
>> 0x0000000000001000 bytes flags: 0x4
>> [ 0.000000] memory[0x24] [0x00000000fff62000-0x000000047fffffff],
>> 0x000000038009e000 bytes flags: 0x0
>> [ 0.000000] reserved.cnt = 0xd
>> [ 0.000000] reserved[0x0] [0x0000000080000000-0x000000008007ffff],
>> 0x0000000000080000 bytes flags: 0x0
>> [ 0.000000] reserved[0x1] [0x0000000080200000-0x00000000815fffff],
>> 0x0000000001400000 bytes flags: 0x0
>> [ 0.000000] reserved[0x2] [0x0000000087f00000-0x0000000087f05fff],
>> 0x0000000000006000 bytes flags: 0x0
>> [ 0.000000] reserved[0x3] [0x00000000db0a2000-0x00000000db0a48b4],
>> 0x00000000000028b5 bytes flags: 0x0
>> [ 0.000000] reserved[0x4] [0x00000000db2a2000-0x00000000dc709fff],
>> 0x0000000001468000 bytes flags: 0x0
>> [ 0.000000] reserved[0x5] [0x00000000fe701000-0x00000000fe701fff],
>> 0x0000000000001000 bytes flags: 0x0
>> [ 0.000000] reserved[0x6] [0x00000000fe704040-0x00000000fe70404f],
>> 0x0000000000000010 bytes flags: 0x0
>> [ 0.000000] reserved[0x7] [0x000000046ffe1d40-0x000000047dfe253f],
>> 0x000000000e000800 bytes flags: 0x0
>> [ 0.000000] reserved[0x8] [0x000000047dfe2548-0x000000047dfe2578],
>> 0x0000000000000031 bytes flags: 0x0
>> [ 0.000000] reserved[0x9] [0x000000047dfe2580-0x000000047dfe25ae],
>> 0x000000000000002f bytes flags: 0x0
>> [ 0.000000] reserved[0xa] [0x000000047dfe25b0-0x000000047dfe25de],
>> 0x000000000000002f bytes flags: 0x0
>> [ 0.000000] reserved[0xb] [0x000000047dfe25e0-0x000000047dfefffb],
>> 0x000000000000da1c bytes flags: 0x0
>> [ 0.000000] reserved[0xc] [0x000000047dff0000-0x000000047fffffff],
>> 0x0000000002010000 bytes flags: 0x0
>>
>> Best regards
>>
>> Heinrich
>>
>> >
>> > >
>> > > Signed-off-by: Heinrich Schuchardt <[email protected]>
>> > > ---
>> > > arch/riscv/Kconfig | 1 +
>> > > 1 file changed, 1 insertion(+)
>> > >
>> > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> > > index 4f7b70ae7c31..a6e57614c3fd 100644
>> > > --- a/arch/riscv/Kconfig
>> > > +++ b/arch/riscv/Kconfig
>> > > @@ -31,6 +31,7 @@ config RISCV
>> > > select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
>> > > select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL
>> > > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>> > > + select ARCH_KEEP_MEMBLOCK
>> > > select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
>> > > select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
>> > > select ARCH_SUPPORTS_HUGETLBFS if MMU
>>
>>
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