From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Signed-off-by: Vanshidhar Konda <redacted>
---
arch/arm64/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
@@ -983,7 +983,7 @@ config SCHED_SMTconfigNR_CPUSint"Maximum number of CPUs (2-4096)"range24096-default"256"+default"512"configHOTPLUG_CPUbool"Support for hot-pluggable CPUs"
--
2.29.2
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From: Will Deacon <will@kernel.org> Date: 2021-01-11 10:57:26
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping
the number, it's just nice to be able to say specifically _why_ we're dong
it.
Thanks,
Will
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On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
Thanks,
Vanshi
From: Randy Dunlap <hidden> Date: 2021-01-11 18:04:10
On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
quoted
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping.
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.
--
~Randy
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On Mon, Jan 11, 2021 at 10:03:18AM -0800, Randy Dunlap wrote:
[EXTERNAL EMAIL NOTICE: This email originated from an external sender. Please be mindful of safe email handling and proprietary information protection practices.]
On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
quoted
On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
quoted
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping.
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.
Sorry. I should have been more clear in my earlier statement. We
currently have systems in development internally, to be available
publicly later, that support more than 256 cores. Given the time it
takes for a kernel version to be adopted by distros it makes sense to
change the defconfig now rather than later.
Thanks,
Vanshi
On Mon, Jan 11, 2021 at 10:03:18AM -0800, Randy Dunlap wrote:
On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
quoted
On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
quoted
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping.
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.
We still aim for the arm64 defconfig to run on all supported SoCs, even
if not optimally. Distros indeed tweak the config to their needs.
--
Catalin
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On Mon, Jan 11, 2021 at 06:25:27PM +0000, Catalin Marinas wrote:
On Mon, Jan 11, 2021 at 10:03:18AM -0800, Randy Dunlap wrote:
quoted
On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
quoted
On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
quoted
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping.
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.
We still aim for the arm64 defconfig to run on all supported SoCs, even
if not optimally. Distros indeed tweak the config to their needs.
Would "all supported SoCs" mean only SoCs that are currently available
publicly? Could we include support for SoCs/systems in development but
to be available publicly in the next few years?
Thanks,
Vanshi
From: Will Deacon <will@kernel.org> Date: 2021-01-12 14:27:52
On Mon, Jan 11, 2021 at 09:20:03PM -0800, Vanshidhar Konda wrote:
On Mon, Jan 11, 2021 at 06:25:27PM +0000, Catalin Marinas wrote:
quoted
On Mon, Jan 11, 2021 at 10:03:18AM -0800, Randy Dunlap wrote:
quoted
On 1/11/21 9:57 AM, Vanshidhar Konda wrote:
quoted
On Mon, Jan 11, 2021 at 10:56:36AM +0000, Will Deacon wrote:
quoted
On Sat, Jan 09, 2021 at 09:36:15PM -0800, vanshikonda@os.amperecomputing.com wrote:
quoted
From: Vanshidhar Konda <redacted>
Increase the default value of NR_CPUS to 512 from 256. This will
enable the defconfig kernel to support platforms that have upto
512 cores.
Do we already support such a platform, and what is it? I'm fine with bumping.
the number, it's just nice to be able to say specifically _why_ we're dong
it.
I'm not aware of any publicly available systems that run into the 256
core limitation. At Ampere we have internal systems that would benefit
from this change as they support more than 256 cores.
But what does that have to do with the default value?
Do you expect to run defconfig kernels?
I don't ever expect that.
We still aim for the arm64 defconfig to run on all supported SoCs, even
if not optimally. Distros indeed tweak the config to their needs.
Would "all supported SoCs" mean only SoCs that are currently available
publicly? Could we include support for SoCs/systems in development but
to be available publicly in the next few years?
I don't really see the need to rush that into defconfig, so I'd prefer
to make the update when something actually exists otherwise it's really
hard to keep track of why we made the decision (especially as unreleased
hardware is liable to change).
Will
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