In the beginning, mm/gup_benchmark.c supported get_user_pages_fast() only, but right now, it supports the benchmarking of a couple of get_user_pages() related calls like: * get_user_pages_fast() * get_user_pages() * pin_user_pages_fast() * pin_user_pages() The documentation is confusing and needs update.
Cc: John Hubbard jhubbard@nvidia.com Cc: Keith Busch keith.busch@intel.com Cc: Ira Weiny ira.weiny@intel.com Cc: Kirill A. Shutemov kirill.shutemov@linux.intel.com Signed-off-by: Barry Song song.bao.hua@hisilicon.com --- mm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/Kconfig b/mm/Kconfig index 6c974888f86f..f7c9374da7b3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -831,10 +831,10 @@ config PERCPU_STATS be used to help understand percpu memory usage.
config GUP_BENCHMARK - bool "Enable infrastructure for get_user_pages_fast() benchmarking" + bool "Enable infrastructure for get_user_pages() and related calls benchmarking" help Provides /sys/kernel/debug/gup_benchmark that helps with testing - performance of get_user_pages_fast(). + performance of get_user_pages() and related calls.
See tools/testing/selftests/vm/gup_benchmark.c
On 8/20/20 8:25 PM, Barry Song wrote:
In the beginning, mm/gup_benchmark.c supported get_user_pages_fast() only, but right now, it supports the benchmarking of a couple of get_user_pages() related calls like:
- get_user_pages_fast()
- get_user_pages()
- pin_user_pages_fast()
- pin_user_pages()
The documentation is confusing and needs update.
hmmm, it's not that confusing, given that pin_user_pages() and get_user_pages() use the same underlying get_user_pages() implementation.
Cc: John Hubbard jhubbard@nvidia.com Cc: Keith Busch keith.busch@intel.com Cc: Ira Weiny ira.weiny@intel.com Cc: Kirill A. Shutemov kirill.shutemov@linux.intel.com Signed-off-by: Barry Song song.bao.hua@hisilicon.com
mm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/Kconfig b/mm/Kconfig index 6c974888f86f..f7c9374da7b3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -831,10 +831,10 @@ config PERCPU_STATS be used to help understand percpu memory usage. config GUP_BENCHMARK
- bool "Enable infrastructure for get_user_pages_fast() benchmarking"
- bool "Enable infrastructure for get_user_pages() and related calls benchmarking"
If we really want to go to the trouble of tweaking this, then I'd go with something more like:
"Enable infrastructure for get_user_pages() and pin_user_pages benchmarking"
...but I don't think it really warrants a patch just yet. *However*, my judgment is skewed right now, because I'm planning a small patchset to split up gup_benchmark a little bit, and to add some more testing and take advantage of parts of it to do a dump_page() test. At which point "related calls" would make more sense, but then it would be different enough that this patch would still need changing.
So I'm inclined to just recommend leaving this alone for a bit, but if others want to put it in, I'm OK with that too.
help Provides /sys/kernel/debug/gup_benchmark that helps with testing
performance of get_user_pages_fast().
performance of get_user_pages() and related calls.See tools/testing/selftests/vm/gup_benchmark.c
thanks,
-----Original Message----- From: linux-kselftest-owner@vger.kernel.org [mailto:linux-kselftest-owner@vger.kernel.org] On Behalf Of John Hubbard Sent: Friday, August 21, 2020 3:51 PM To: Song Bao Hua (Barry Song) song.bao.hua@hisilicon.com; akpm@linux-foundation.org; linux-mm@kvack.org; linux-kselftest@vger.kernel.org Cc: Linuxarm linuxarm@huawei.com; linux-kernel@vger.kernel.org; Keith Busch keith.busch@intel.com; Ira Weiny ira.weiny@intel.com; Kirill A . Shutemov kirill.shutemov@linux.intel.com Subject: Re: [PATCH] mm/gup_benchmark: update the documentation in Kconfig
On 8/20/20 8:25 PM, Barry Song wrote:
In the beginning, mm/gup_benchmark.c supported get_user_pages_fast() only, but right now, it supports the benchmarking of a couple of get_user_pages() related calls like:
- get_user_pages_fast()
- get_user_pages()
- pin_user_pages_fast()
- pin_user_pages()
The documentation is confusing and needs update.
hmmm, it's not that confusing, given that pin_user_pages() and get_user_pages() use the same underlying get_user_pages() implementation.
get_user_pages_fast() is not get_user_pages(). It is a specific function :-)
In the beginning, gup_benchmark was only for get_user_pages_fast(): https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/mm...
Cc: John Hubbard jhubbard@nvidia.com Cc: Keith Busch keith.busch@intel.com Cc: Ira Weiny ira.weiny@intel.com Cc: Kirill A. Shutemov kirill.shutemov@linux.intel.com Signed-off-by: Barry Song song.bao.hua@hisilicon.com
mm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/Kconfig b/mm/Kconfig index 6c974888f86f..f7c9374da7b3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -831,10 +831,10 @@ config PERCPU_STATS be used to help understand percpu memory usage.
config GUP_BENCHMARK
- bool "Enable infrastructure for get_user_pages_fast() benchmarking"
- bool "Enable infrastructure for get_user_pages() and related calls
benchmarking"
If we really want to go to the trouble of tweaking this, then I'd go with something more like:
"Enable infrastructure for get_user_pages() and pin_user_pages benchmarking"
...but I don't think it really warrants a patch just yet. *However*, my judgment is skewed right now, because I'm planning a small patchset to split up gup_benchmark a little bit, and to add some more testing and take advantage of parts of it to do a dump_page() test. At which point "related calls" would make more sense, but then it would be different enough that this patch would still need changing.
Ok. Fair enough. I was copying the "related calls" from: Documentation/core-api/pin_user_pages.rst
So I'm inclined to just recommend leaving this alone for a bit, but if others want to put it in, I'm OK with that too.
help Provides /sys/kernel/debug/gup_benchmark that helps with testing
performance of get_user_pages_fast().
performance of get_user_pages() and related calls.See tools/testing/selftests/vm/gup_benchmark.c
Thanks Barry
linux-kselftest-mirror@lists.linaro.org
-
Barry Song -
John Hubbard -
Song Bao Hua (Barry Song)