[PATCH 0/2] dma-mapping: benchmark: modify the dma_map_benchmark directory

[PATCH 0/2] dma-mapping: benchmark: modify the dma_map_benchmark directory

[Qinxin Xia]

This series moves the dma_map_benchmark utility out of the selftests
directory and fixes an ABI regression introduced in an earlier change.
No functional behaviour of the benchmark itself is changed.

Qinxin Xia (2):
  tools/dma: move dma_map_benchmark from selftests to tools/dma
  dma-mapping: benchmark: Add padding to ensure uABI remained consistent

 include/linux/map_benchmark.h                     |  1 +
 tools/Makefile                                    | 13 +++++++------
 tools/dma/Makefile                                | 15 +++++++++++++++
 tools/{testing/selftests => }/dma/config          |  0
 .../selftests => }/dma/dma_map_benchmark.c        |  0
 tools/testing/selftests/dma/Makefile              |  7 -------
 6 files changed, 23 insertions(+), 13 deletions(-)
 create mode 100644 tools/dma/Makefile
 rename tools/{testing/selftests => }/dma/config (100%)
 rename tools/{testing/selftests => }/dma/dma_map_benchmark.c (100%)
 delete mode 100644 tools/testing/selftests/dma/Makefile

-- 
2.33.0

[PATCH 1/2] tools/dma: move dma_map_benchmark from selftests to tools/dma

[Qinxin Xia]

dma_map_benchmark is a standalone developer tool rather than an
automated selftest.  It has no pass/fail criteria, expects manual
invocation, and is built as a normal userspace binary.Move it to
tools/dma/ and add a minimal, the original selftest.Makefile entry
is removed to avoid duplication.

Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
---
 tools/Makefile                                    | 13 +++++++------
 tools/dma/Makefile                                | 15 +++++++++++++++
 tools/{testing/selftests => }/dma/config          |  0
 .../selftests => }/dma/dma_map_benchmark.c        |  0
 tools/testing/selftests/dma/Makefile              |  7 -------
 5 files changed, 22 insertions(+), 13 deletions(-)
 create mode 100644 tools/dma/Makefile
 rename tools/{testing/selftests => }/dma/config (100%)
 rename tools/{testing/selftests => }/dma/dma_map_benchmark.c (100%)
 delete mode 100644 tools/testing/selftests/dma/Makefile

diff --git a/tools/Makefile b/tools/Makefile
index c31cbbd12c45..72dc0e936632 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -14,6 +14,7 @@ help:
 	@echo '  counter                - counter tools'
 	@echo '  cpupower               - a tool for all things x86 CPU power'
 	@echo '  debugging              - tools for debugging'
+	@echo '  dma                    - dma map benchmark'
 	@echo '  firewire               - the userspace part of nosy, an IEEE-1394 traffic sniffer'
 	@echo '  firmware               - Firmware tools'
 	@echo '  freefall               - laptop accelerometer program for disk protection'
@@ -69,7 +70,7 @@ acpi: FORCE
 cpupower: FORCE
 	$(call descend,power/$@)
 
-counter firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
+counter dma firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
 	$(call descend,$@)
 
 bpf/%: FORCE
@@ -122,7 +123,7 @@ kvm_stat: FORCE
 ynl: FORCE
 	$(call descend,net/ynl)
 
-all: acpi counter cpupower gpio hv firewire \
+all: acpi counter cpupower dma gpio hv firewire \
 		perf selftests bootconfig spi turbostat usb \
 		virtio mm bpf x86_energy_perf_policy \
 		tmon freefall iio objtool kvm_stat wmi \
@@ -134,7 +135,7 @@ acpi_install:
 cpupower_install:
 	$(call descend,power/$(@:_install=),install)
 
-counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
+counter_install dma_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
 	$(call descend,$(@:_install=),install)
 
 selftests_install:
@@ -164,7 +165,7 @@ kvm_stat_install:
 ynl_install:
 	$(call descend,net/$(@:_install=),install)
 
-install: acpi_install counter_install cpupower_install gpio_install \
+install: acpi_install counter_install cpupower_install dma_install gpio_install \
 		hv_install firewire_install iio_install \
 		perf_install selftests_install turbostat_install usb_install \
 		virtio_install mm_install bpf_install x86_energy_perf_policy_install \
@@ -178,7 +179,7 @@ acpi_clean:
 cpupower_clean:
 	$(call descend,power/cpupower,clean)
 
-counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
+counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
 	$(call descend,$(@:_clean=),clean)
 
 libapi_clean:
@@ -224,7 +225,7 @@ build_clean:
 ynl_clean:
 	$(call descend,net/$(@:_clean=),clean)
 
-clean: acpi_clean counter_clean cpupower_clean hv_clean firewire_clean \
+clean: acpi_clean counter_clean cpupower_clean dma_clean hv_clean firewire_clean \
 		perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
 		mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
 		freefall_clean build_clean libbpf_clean libsubcmd_clean \
diff --git a/tools/dma/Makefile b/tools/dma/Makefile
new file mode 100644
index 000000000000..6282eb41e51a
--- /dev/null
+++ b/tools/dma/Makefile
@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0
+bindir ?= /usr/bin
+
+CFLAGS += -I../../include -I../../usr/include
+
+all:
+	$(CC) $(CFLAGS) dma_map_benchmark.c -o dma_map_benchmark
+
+install: all
+	install -D dma_map_benchmark $(bindir)/bin/dma_map_benchmark
+
+clean:
+	rm -f dma_map_benchmark
+
+.PHONY: all install clean
diff --git a/tools/testing/selftests/dma/config b/tools/dma/config
similarity index 100%
rename from tools/testing/selftests/dma/config
rename to tools/dma/config
diff --git a/tools/testing/selftests/dma/dma_map_benchmark.c b/tools/dma/dma_map_benchmark.c
similarity index 100%
rename from tools/testing/selftests/dma/dma_map_benchmark.c
rename to tools/dma/dma_map_benchmark.c
diff --git a/tools/testing/selftests/dma/Makefile b/tools/testing/selftests/dma/Makefile
deleted file mode 100644
index cd8c5ece1cba..000000000000
--- a/tools/testing/selftests/dma/Makefile
+++ /dev/null
@@ -1,7 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0
-CFLAGS += -I../../../../usr/include/
-CFLAGS += -I../../../../include/
-
-TEST_GEN_PROGS := dma_map_benchmark
-
-include ../lib.mk
-- 
2.33.0

[PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Qinxin Xia]

The padding field in the structure was previously reserved to
maintain a stable interface for potential new fields, ensuring
compatibility with user-space shared data structures.
However,it was accidentally removed by tiantao in a prior commit,
which may lead to incompatibility between user space and the kernel.

This patch reinstates the padding to restore the original structure
layout and preserve compatibility.

Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
Cc: stable@vger.kernel.org
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
---
 include/linux/map_benchmark.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
index 62674c83bde4..2ac2fe52f248 100644
--- a/include/linux/map_benchmark.h
+++ b/include/linux/map_benchmark.h
@@ -27,5 +27,6 @@ struct map_benchmark {
 	__u32 dma_dir; /* DMA data direction */
 	__u32 dma_trans_ns; /* time for DMA transmission in ns */
 	__u32 granule;  /* how many PAGE_SIZE will do map/unmap once a time */
+	__u8 expansion[76];     /* For future use */
 };
 #endif /* _KERNEL_DMA_BENCHMARK_H */
-- 
2.33.0

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Barry Song]

On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>
> The padding field in the structure was previously reserved to
> maintain a stable interface for potential new fields, ensuring
> compatibility with user-space shared data structures.
> However,it was accidentally removed by tiantao in a prior commit,
> which may lead to incompatibility between user space and the kernel.
>
> This patch reinstates the padding to restore the original structure
> layout and preserve compatibility.
>
> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
> Cc: stable@vger.kernel.org
> Acked-by: Barry Song <baohua@kernel.org>
> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>

I don’t think these two patches should be part of the same series. This
one is a bug fix and should be handled separately—ideally picked up on
its own and backported to stable.

Also, the subject should not say "Add"—it should be "Restore". I assume
Marek can handle it?

> ---
>  include/linux/map_benchmark.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
> index 62674c83bde4..2ac2fe52f248 100644
> --- a/include/linux/map_benchmark.h
> +++ b/include/linux/map_benchmark.h
> @@ -27,5 +27,6 @@ struct map_benchmark {
>         __u32 dma_dir; /* DMA data direction */
>         __u32 dma_trans_ns; /* time for DMA transmission in ns */
>         __u32 granule;  /* how many PAGE_SIZE will do map/unmap once a time */
> +       __u8 expansion[76];     /* For future use */
>  };
>  #endif /* _KERNEL_DMA_BENCHMARK_H */
> --
> 2.33.0
>

Thanks
Barry

Re: [PATCH 1/2] tools/dma: move dma_map_benchmark from selftests to tools/dma

[Barry Song]

On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>
> dma_map_benchmark is a standalone developer tool rather than an
> automated selftest.  It has no pass/fail criteria, expects manual
> invocation, and is built as a normal userspace binary.Move it to
> tools/dma/ and add a minimal, the original selftest.Makefile entry
> is removed to avoid duplication.
>
> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> ---
>  tools/Makefile                                    | 13 +++++++------
>  tools/dma/Makefile                                | 15 +++++++++++++++
>  tools/{testing/selftests => }/dma/config          |  0
>  .../selftests => }/dma/dma_map_benchmark.c        |  0
>  tools/testing/selftests/dma/Makefile              |  7 -------
>  5 files changed, 22 insertions(+), 13 deletions(-)
>  create mode 100644 tools/dma/Makefile
>  rename tools/{testing/selftests => }/dma/config (100%)
>  rename tools/{testing/selftests => }/dma/dma_map_benchmark.c (100%)
>  delete mode 100644 tools/testing/selftests/dma/Makefile
>
> diff --git a/tools/Makefile b/tools/Makefile
> index c31cbbd12c45..72dc0e936632 100644
> --- a/tools/Makefile
> +++ b/tools/Makefile
> @@ -14,6 +14,7 @@ help:
>         @echo '  counter                - counter tools'
>         @echo '  cpupower               - a tool for all things x86 CPU power'
>         @echo '  debugging              - tools for debugging'
> +       @echo '  dma                    - dma map benchmark'

Please make it more general. Right now we only have the DMA map
benchmark, but we might add more DMA mapping tools in the future.
For examples: tools for dma mapping

>         @echo '  firewire               - the userspace part of nosy, an IEEE-1394 traffic sniffer'
>         @echo '  firmware               - Firmware tools'
>         @echo '  freefall               - laptop accelerometer program for disk protection'
> @@ -69,7 +70,7 @@ acpi: FORCE
>  cpupower: FORCE
>         $(call descend,power/$@)
>
> -counter firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
> +counter dma firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
>         $(call descend,$@)
>
>  bpf/%: FORCE
> @@ -122,7 +123,7 @@ kvm_stat: FORCE
>  ynl: FORCE
>         $(call descend,net/ynl)
>
> -all: acpi counter cpupower gpio hv firewire \
> +all: acpi counter cpupower dma gpio hv firewire \
>                 perf selftests bootconfig spi turbostat usb \
>                 virtio mm bpf x86_energy_perf_policy \
>                 tmon freefall iio objtool kvm_stat wmi \
> @@ -134,7 +135,7 @@ acpi_install:
>  cpupower_install:
>         $(call descend,power/$(@:_install=),install)
>
> -counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
> +counter_install dma_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
>         $(call descend,$(@:_install=),install)
>
>  selftests_install:
> @@ -164,7 +165,7 @@ kvm_stat_install:
>  ynl_install:
>         $(call descend,net/$(@:_install=),install)
>
> -install: acpi_install counter_install cpupower_install gpio_install \
> +install: acpi_install counter_install cpupower_install dma_install gpio_install \
>                 hv_install firewire_install iio_install \
>                 perf_install selftests_install turbostat_install usb_install \
>                 virtio_install mm_install bpf_install x86_energy_perf_policy_install \
> @@ -178,7 +179,7 @@ acpi_clean:
>  cpupower_clean:
>         $(call descend,power/cpupower,clean)
>
> -counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
> +counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
>         $(call descend,$(@:_clean=),clean)
>
>  libapi_clean:
> @@ -224,7 +225,7 @@ build_clean:
>  ynl_clean:
>         $(call descend,net/$(@:_clean=),clean)
>
> -clean: acpi_clean counter_clean cpupower_clean hv_clean firewire_clean \
> +clean: acpi_clean counter_clean cpupower_clean dma_clean hv_clean firewire_clean \
>                 perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
>                 mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
>                 freefall_clean build_clean libbpf_clean libsubcmd_clean \
> diff --git a/tools/dma/Makefile b/tools/dma/Makefile
> new file mode 100644
> index 000000000000..6282eb41e51a
> --- /dev/null
> +++ b/tools/dma/Makefile
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: GPL-2.0
> +bindir ?= /usr/bin
> +
> +CFLAGS += -I../../include -I../../usr/include
> +
> +all:
> +       $(CC) $(CFLAGS) dma_map_benchmark.c -o dma_map_benchmark
> +
> +install: all
> +       install -D dma_map_benchmark $(bindir)/bin/dma_map_benchmark
> +
> +clean:
> +       rm -f dma_map_benchmark

Please make the Makefile more general. Right now I only have
dma_map_benchmark, but the Makefile shouldn't be tailored specifically
for just that one. dma_map_benchmark is one of those targets.

And I feel $(bindir)/bin/dma_map_benchmark is an incorrect folder.

Thanks
Barry

Re: [PATCH 1/2] tools/dma: move dma_map_benchmark from selftests to tools/dma

[Qinxin Xia]

On 2025/7/24 17:25:16, Barry Song <21cnbao@gmail.com> wrote:
> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>
>> dma_map_benchmark is a standalone developer tool rather than an
>> automated selftest.  It has no pass/fail criteria, expects manual
>> invocation, and is built as a normal userspace binary.Move it to
>> tools/dma/ and add a minimal, the original selftest.Makefile entry
>> is removed to avoid duplication.
>>
>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>> ---
>>   tools/Makefile                                    | 13 +++++++------
>>   tools/dma/Makefile                                | 15 +++++++++++++++
>>   tools/{testing/selftests => }/dma/config          |  0
>>   .../selftests => }/dma/dma_map_benchmark.c        |  0
>>   tools/testing/selftests/dma/Makefile              |  7 -------
>>   5 files changed, 22 insertions(+), 13 deletions(-)
>>   create mode 100644 tools/dma/Makefile
>>   rename tools/{testing/selftests => }/dma/config (100%)
>>   rename tools/{testing/selftests => }/dma/dma_map_benchmark.c (100%)
>>   delete mode 100644 tools/testing/selftests/dma/Makefile
>>
>> diff --git a/tools/Makefile b/tools/Makefile
>> index c31cbbd12c45..72dc0e936632 100644
>> --- a/tools/Makefile
>> +++ b/tools/Makefile
>> @@ -14,6 +14,7 @@ help:
>>          @echo '  counter                - counter tools'
>>          @echo '  cpupower               - a tool for all things x86 CPU power'
>>          @echo '  debugging              - tools for debugging'
>> +       @echo '  dma                    - dma map benchmark'
> 
> Please make it more general. Right now we only have the DMA map
> benchmark, but we might add more DMA mapping tools in the future.
> For examples: tools for dma mapping
> 
ok,I will fix in next version.>>          @echo '  firewire 
  - the userspace part of nosy, an IEEE-1394 traffic sniffer'
>>          @echo '  firmware               - Firmware tools'
>>          @echo '  freefall               - laptop accelerometer program for disk protection'
>> @@ -69,7 +70,7 @@ acpi: FORCE
>>   cpupower: FORCE
>>          $(call descend,power/$@)
>>
>> -counter firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
>> +counter dma firewire hv guest bootconfig spi usb virtio mm bpf iio gpio objtool leds wmi firmware debugging tracing: FORCE
>>          $(call descend,$@)
>>
>>   bpf/%: FORCE
>> @@ -122,7 +123,7 @@ kvm_stat: FORCE
>>   ynl: FORCE
>>          $(call descend,net/ynl)
>>
>> -all: acpi counter cpupower gpio hv firewire \
>> +all: acpi counter cpupower dma gpio hv firewire \
>>                  perf selftests bootconfig spi turbostat usb \
>>                  virtio mm bpf x86_energy_perf_policy \
>>                  tmon freefall iio objtool kvm_stat wmi \
>> @@ -134,7 +135,7 @@ acpi_install:
>>   cpupower_install:
>>          $(call descend,power/$(@:_install=),install)
>>
>> -counter_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
>> +counter_install dma_install firewire_install gpio_install hv_install iio_install perf_install bootconfig_install spi_install usb_install virtio_install mm_install bpf_install objtool_install wmi_install debugging_install tracing_install:
>>          $(call descend,$(@:_install=),install)
>>
>>   selftests_install:
>> @@ -164,7 +165,7 @@ kvm_stat_install:
>>   ynl_install:
>>          $(call descend,net/$(@:_install=),install)
>>
>> -install: acpi_install counter_install cpupower_install gpio_install \
>> +install: acpi_install counter_install cpupower_install dma_install gpio_install \
>>                  hv_install firewire_install iio_install \
>>                  perf_install selftests_install turbostat_install usb_install \
>>                  virtio_install mm_install bpf_install x86_energy_perf_policy_install \
>> @@ -178,7 +179,7 @@ acpi_clean:
>>   cpupower_clean:
>>          $(call descend,power/cpupower,clean)
>>
>> -counter_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
>> +counter_clean dma_clean hv_clean firewire_clean bootconfig_clean spi_clean usb_clean virtio_clean mm_clean wmi_clean bpf_clean iio_clean gpio_clean objtool_clean leds_clean firmware_clean debugging_clean tracing_clean:
>>          $(call descend,$(@:_clean=),clean)
>>
>>   libapi_clean:
>> @@ -224,7 +225,7 @@ build_clean:
>>   ynl_clean:
>>          $(call descend,net/$(@:_clean=),clean)
>>
>> -clean: acpi_clean counter_clean cpupower_clean hv_clean firewire_clean \
>> +clean: acpi_clean counter_clean cpupower_clean dma_clean hv_clean firewire_clean \
>>                  perf_clean selftests_clean turbostat_clean bootconfig_clean spi_clean usb_clean virtio_clean \
>>                  mm_clean bpf_clean iio_clean x86_energy_perf_policy_clean tmon_clean \
>>                  freefall_clean build_clean libbpf_clean libsubcmd_clean \
>> diff --git a/tools/dma/Makefile b/tools/dma/Makefile
>> new file mode 100644
>> index 000000000000..6282eb41e51a
>> --- /dev/null
>> +++ b/tools/dma/Makefile
>> @@ -0,0 +1,15 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +bindir ?= /usr/bin
>> +
>> +CFLAGS += -I../../include -I../../usr/include
>> +
>> +all:
>> +       $(CC) $(CFLAGS) dma_map_benchmark.c -o dma_map_benchmark
>> +
>> +install: all
>> +       install -D dma_map_benchmark $(bindir)/bin/dma_map_benchmark
>> +
>> +clean:
>> +       rm -f dma_map_benchmark
> 
> Please make the Makefile more general. Right now I only have
> dma_map_benchmark, but the Makefile shouldn't be tailored specifically
> for just that one. dma_map_benchmark is one of those targets.
> 
> And I feel $(bindir)/bin/dma_map_benchmark is an incorrect folder.
> 
> Thanks
> Barry
Ok, in next version.I will make it more general.

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Qinxin Xia]

On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>
>> The padding field in the structure was previously reserved to
>> maintain a stable interface for potential new fields, ensuring
>> compatibility with user-space shared data structures.
>> However,it was accidentally removed by tiantao in a prior commit,
>> which may lead to incompatibility between user space and the kernel.
>>
>> This patch reinstates the padding to restore the original structure
>> layout and preserve compatibility.
>>
>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
>> Cc: stable@vger.kernel.org
>> Acked-by: Barry Song <baohua@kernel.org>
>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> 
> I don’t think these two patches should be part of the same series. This
> one is a bug fix and should be handled separately—ideally picked up on
> its own and backported to stable.
> 
> Also, the subject should not say "Add"—it should be "Restore". I assume
> Marek can handle it?
> 
>> ---
>>   include/linux/map_benchmark.h | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
>> index 62674c83bde4..2ac2fe52f248 100644
>> --- a/include/linux/map_benchmark.h
>> +++ b/include/linux/map_benchmark.h
>> @@ -27,5 +27,6 @@ struct map_benchmark {
>>          __u32 dma_dir; /* DMA data direction */
>>          __u32 dma_trans_ns; /* time for DMA transmission in ns */
>>          __u32 granule;  /* how many PAGE_SIZE will do map/unmap once a time */
>> +       __u8 expansion[76];     /* For future use */
>>   };
>>   #endif /* _KERNEL_DMA_BENCHMARK_H */
>> --
>> 2.33.0
>>
> 
> Thanks
> Barry

Ok, I will send a new version to fix it.
Thanks

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Barry Song]

On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>
>
>
> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> > On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >>
> >> The padding field in the structure was previously reserved to
> >> maintain a stable interface for potential new fields, ensuring
> >> compatibility with user-space shared data structures.
> >> However,it was accidentally removed by tiantao in a prior commit,
> >> which may lead to incompatibility between user space and the kernel.
> >>
> >> This patch reinstates the padding to restore the original structure
> >> layout and preserve compatibility.
> >>
> >> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
> >> Cc: stable@vger.kernel.org
> >> Acked-by: Barry Song <baohua@kernel.org>
> >> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >
> > I don’t think these two patches should be part of the same series. This
> > one is a bug fix and should be handled separately—ideally picked up on
> > its own and backported to stable.
> >
> > Also, the subject should not say "Add"—it should be "Restore". I assume
> > Marek can handle it?
...
> Ok, I will send a new version to fix it.

If Marek can help fix it while picking it up into the dma-mapping tree, you
might not need to send a new version.

Honestly, I hope this gets merged soon—it feels like it's been
overdue for quite a while.

Thanks
Barry

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Marek Szyprowski]

On 24.07.2025 11:42, Barry Song wrote:
> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>> The padding field in the structure was previously reserved to
>>>> maintain a stable interface for potential new fields, ensuring
>>>> compatibility with user-space shared data structures.
>>>> However,it was accidentally removed by tiantao in a prior commit,
>>>> which may lead to incompatibility between user space and the kernel.
>>>>
>>>> This patch reinstates the padding to restore the original structure
>>>> layout and preserve compatibility.
>>>>
>>>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
>>>> Cc: stable@vger.kernel.org
>>>> Acked-by: Barry Song <baohua@kernel.org>
>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>>> I don’t think these two patches should be part of the same series. This
>>> one is a bug fix and should be handled separately—ideally picked up on
>>> its own and backported to stable.
>>>
>>> Also, the subject should not say "Add"—it should be "Restore". I assume
>>> Marek can handle it?
> ...
>> Ok, I will send a new version to fix it.
> If Marek can help fix it while picking it up into the dma-mapping tree, you
> might not need to send a new version.
>
> Honestly, I hope this gets merged soon—it feels like it's been
> overdue for quite a while.

I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I 
will take it after this merge window.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Barry Song]

On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> On 24.07.2025 11:42, Barry Song wrote:
> > On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> >>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >>>> The padding field in the structure was previously reserved to
> >>>> maintain a stable interface for potential new fields, ensuring
> >>>> compatibility with user-space shared data structures.
> >>>> However,it was accidentally removed by tiantao in a prior commit,
> >>>> which may lead to incompatibility between user space and the kernel.
> >>>>
> >>>> This patch reinstates the padding to restore the original structure
> >>>> layout and preserve compatibility.
> >>>>
> >>>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
> >>>> Cc: stable@vger.kernel.org
> >>>> Acked-by: Barry Song <baohua@kernel.org>
> >>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >>> I don’t think these two patches should be part of the same series. This
> >>> one is a bug fix and should be handled separately—ideally picked up on
> >>> its own and backported to stable.
> >>>
> >>> Also, the subject should not say "Add"—it should be "Restore". I assume
> >>> Marek can handle it?
> > ...
> >> Ok, I will send a new version to fix it.
> > If Marek can help fix it while picking it up into the dma-mapping tree, you
> > might not need to send a new version.
> >
> > Honestly, I hope this gets merged soon—it feels like it's been
> > overdue for quite a while.
>
> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
> will take it after this merge window.

Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
for quite a while, likely he moved to another company some time ago. It looks
like Yicong has volunteered to take this on:

https://lkml.indiana.edu/2408.1/08865.html

I'm not sure if that's still the case. If it is, would Yicong be able to
resend the email with my ack?

>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>

Thanks
Barry

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Yicong Yang]

Hi Barry,

On 2025/8/4 12:47, Barry Song wrote:
> On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>>
>> On 24.07.2025 11:42, Barry Song wrote:
>>> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
>>>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>>>> The padding field in the structure was previously reserved to
>>>>>> maintain a stable interface for potential new fields, ensuring
>>>>>> compatibility with user-space shared data structures.
>>>>>> However,it was accidentally removed by tiantao in a prior commit,
>>>>>> which may lead to incompatibility between user space and the kernel.
>>>>>>
>>>>>> This patch reinstates the padding to restore the original structure
>>>>>> layout and preserve compatibility.
>>>>>>
>>>>>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
>>>>>> Cc: stable@vger.kernel.org
>>>>>> Acked-by: Barry Song <baohua@kernel.org>
>>>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>>>>> I don’t think these two patches should be part of the same series. This
>>>>> one is a bug fix and should be handled separately—ideally picked up on
>>>>> its own and backported to stable.
>>>>>
>>>>> Also, the subject should not say "Add"—it should be "Restore". I assume
>>>>> Marek can handle it?
>>> ...
>>>> Ok, I will send a new version to fix it.
>>> If Marek can help fix it while picking it up into the dma-mapping tree, you
>>> might not need to send a new version.
>>>
>>> Honestly, I hope this gets merged soon—it feels like it's been
>>> overdue for quite a while.
>>
>> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
>> will take it after this merge window.
> 
> Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
> for quite a while, likely he moved to another company some time ago. It looks
> like Yicong has volunteered to take this on:
> 
> https://lkml.indiana.edu/2408.1/08865.html
> 
> I'm not sure if that's still the case. If it is, would Yicong be able to
> resend the email with my ack?
> 

thanks for reminding. I think currently Qinxin is more suitable to help with this.
she's working on the smmu stuffs and help look after this benchmark tool internally
for some time :)

Maybe she can help along with you (ack the fact that you're always helping to review
the codes) if it's ok with you.

Thanks.

Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Barry Song]

On Mon, Aug 4, 2025 at 8:12 PM Yicong Yang <yangyicong@huawei.com> wrote:
>
> Hi Barry,
>
> On 2025/8/4 12:47, Barry Song wrote:
> > On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
> > <m.szyprowski@samsung.com> wrote:
> >>
> >> On 24.07.2025 11:42, Barry Song wrote:
> >>> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >>>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> >>>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >>>>>> The padding field in the structure was previously reserved to
> >>>>>> maintain a stable interface for potential new fields, ensuring
> >>>>>> compatibility with user-space shared data structures.
> >>>>>> However,it was accidentally removed by tiantao in a prior commit,
> >>>>>> which may lead to incompatibility between user space and the kernel.
> >>>>>>
> >>>>>> This patch reinstates the padding to restore the original structure
> >>>>>> layout and preserve compatibility.
> >>>>>>
> >>>>>> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
> >>>>>> Cc: stable@vger.kernel.org
> >>>>>> Acked-by: Barry Song <baohua@kernel.org>
> >>>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >>>>> I don’t think these two patches should be part of the same series. This
> >>>>> one is a bug fix and should be handled separately—ideally picked up on
> >>>>> its own and backported to stable.
> >>>>>
> >>>>> Also, the subject should not say "Add"—it should be "Restore". I assume
> >>>>> Marek can handle it?
> >>> ...
> >>>> Ok, I will send a new version to fix it.
> >>> If Marek can help fix it while picking it up into the dma-mapping tree, you
> >>> might not need to send a new version.
> >>>
> >>> Honestly, I hope this gets merged soon—it feels like it's been
> >>> overdue for quite a while.
> >>
> >> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
> >> will take it after this merge window.
> >
> > Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
> > for quite a while, likely he moved to another company some time ago. It looks
> > like Yicong has volunteered to take this on:
> >
> > https://lkml.indiana.edu/2408.1/08865.html
> >
> > I'm not sure if that's still the case. If it is, would Yicong be able to
> > resend the email with my ack?
> >
>
> thanks for reminding. I think currently Qinxin is more suitable to help with this.
> she's working on the smmu stuffs and help look after this benchmark tool internally
> for some time :)
>
> Maybe she can help along with you (ack the fact that you're always helping to review
> the codes) if it's ok with you.

Certainly, Qinxin is welcome to take over. I will be glad to review
the code when time
permits, although my schedule is typically quite occupied with mm.

Thanks
Barry