On 10/29/20 8:06 PM, Jan Kiszka wrote:
> On 29.10.20 17:39, Ralf Ramsauer wrote:
>>
>>
>> On 29/10/2020 17:16, Jan Kiszka wrote:
>>> On 29.10.20 15:55, Ralf Ramsauer wrote:
>>>> On x86_64 systems, this test inmate measures the time that is required to
>>>> read
>>>> a value from main memory. Via rdtsc, it measures the CPU cycles that are
>>>> required for the access. Access can either happen cached, or uncached. In
>>>> case
>>>> of uncached access, the cache line will be flushed before access.
>>>>
>>>> This tool repeats the measurement for 10e6 times, and outputs the
>>>> average cycles that were required for the access. Before accessing the
>>>> actual measurement, a dummy test is used to determine the average
>>>> overhead of one single measurement.
>>>>
>>>> And that's pretty useful, because this tool gives a lot of insights of
>>>> differences between the root and the non-root cell: With tiny effort, we
>>>> can also run it on Linux.
>>>>
>>>> If the 'overhead' time differs between root and non-root cell, this can
>>>> be an indicator that there might be some timing or speed differences
>>>> between the root and non-root cell.
>>>>
>>>> If the 'uncached' or 'cached' average time differs between the non-root
>>>> and root cell, it's an indicator that both might have different hardware
>>>> configurations / setups.
>>>>
>>>> Signed-off-by: Ralf Ramsauer <[email protected]>
>>>> ---
>>>> since v2:
>>>> - Move host code to tools/demos :-)
>>>>
>>>> since v1:
>>>> - Move host code to tools/
>>>>
>>>> since RFC:
>>>> - move the inmate to demos instead of tests
>>>>
>>>>
>>>> .gitignore | 1 +
>>>> inmates/demos/x86/Makefile | 4 +++-
>>>> tools/Makefile | 9 +++++++--
>>>> tools/demos/cache-timings.c | 29 +++++++++++++++++++++++++++++
>>>> 4 files changed, 40 insertions(+), 3 deletions(-)
>>>> create mode 100644 tools/demos/cache-timings.c
>>>>
>>>> diff --git a/.gitignore b/.gitignore
>>>> index 1d8905ab..245733cb 100644
>>>> --- a/.gitignore
>>>> +++ b/.gitignore
>>>> @@ -21,6 +21,7 @@ hypervisor/hypervisor.lds
>>>> inmates/lib/arm/inmate.lds
>>>> inmates/lib/arm64/inmate.lds
>>>> pyjailhouse/pci_defs.py
>>>> +tools/demos/cache-timings
>>>> tools/demos/ivshmem-demo
>>>> tools/jailhouse
>>>> tools/jailhouse-gcov-extract
>>>> diff --git a/inmates/demos/x86/Makefile b/inmates/demos/x86/Makefile
>>>> index f53b739e..47b79869 100644
>>>> --- a/inmates/demos/x86/Makefile
>>>> +++ b/inmates/demos/x86/Makefile
>>>> @@ -13,7 +13,8 @@
>>>> include $(INMATES_LIB)/Makefile.lib
>>>>
>>>> INMATES := tiny-demo.bin apic-demo.bin ioapic-demo.bin 32-bit-demo.bin \
>>>> - pci-demo.bin e1000-demo.bin ivshmem-demo.bin smp-demo.bin
>>>> + pci-demo.bin e1000-demo.bin ivshmem-demo.bin smp-demo.bin \
>>>> + cache-timings.bin
>>>>
>>>> tiny-demo-y := tiny-demo.o
>>>> apic-demo-y := apic-demo.o
>>>> @@ -22,6 +23,7 @@ pci-demo-y := pci-demo.o
>>>> e1000-demo-y := e1000-demo.o
>>>> ivshmem-demo-y := ../ivshmem-demo.o
>>>> smp-demo-y := smp-demo.o
>>>> +cache-timings-y := cache-timings.o
>>>>
>>>> $(eval $(call DECLARE_32_BIT,32-bit-demo))
>>>> 32-bit-demo-y := 32-bit-demo.o
>>>> diff --git a/tools/Makefile b/tools/Makefile
>>>> index 8cf5df84..62585369 100644
>>>> --- a/tools/Makefile
>>>> +++ b/tools/Makefile
>>>> @@ -35,6 +35,13 @@ KBUILD_CFLAGS += $(call cc-option, -fno-pie)
>>>> KBUILD_CFLAGS += $(call cc-option, -no-pie)
>>>>
>>>> BINARIES := jailhouse demos/ivshmem-demo
>>>> +targets += jailhouse.o demos/ivshmem-demo.o
>>>> +
>>>> +ifeq ($(ARCH),x86)
>>>> +BINARIES += demos/cache-timings
>>>> +targets += demos/cache-timings.o
>>>> +endif # $(ARCH),x86
>>>> +
>>>> always-y := $(BINARIES)
>>>>
>>>> HAS_PYTHON_MAKO := \
>>>> @@ -104,8 +111,6 @@ define cmd_gen_man
>>>> sed 's/$${VERSION}/$(shell cat $(src)/../VERSION)/g' $< > $@
>>>> endef
>>>>
>>>> -targets += jailhouse.o demos/ivshmem-demo.o
>>>> -
>>>> $(obj)/%: $(obj)/%.o
>>>> $(call if_changed,ld)
>>>>
>>>> diff --git a/tools/demos/cache-timings.c b/tools/demos/cache-timings.c
>>>> new file mode 100644
>>>> index 00000000..2c591dab
>>>> --- /dev/null
>>>> +++ b/tools/demos/cache-timings.c
>>>> @@ -0,0 +1,29 @@
>>>> +/*
>>>> + * Jailhouse, a Linux-based partitioning hypervisor
>>>> + *
>>>> + * Copyright (c) OTH Regensburg, 2020
>>>> + *
>>>> + * Authors:
>>>> + * Ralf Ramsauer <[email protected]>
>>>> + *
>>>> + * This work is licensed under the terms of the GNU GPL, version 2. See
>>>> + * the COPYING file in the top-level directory.
>>>> + */
>>>> +
>>>> +#include <stdbool.h>
>>>> +#include <stdio.h>
>>>> +
>>>> +#define printk printf
>>>> +
>>>> +typedef unsigned int u32;
>>>> +typedef unsigned long long u64;
>>>> +
>>>> +void inmate_main(void);
>>>> +
>>>> +#include "../inmates/demos/x86/cache-timings-common.c"
>>>> +
>>>> +int main(void)
>>>> +{
>>>> + inmate_main();
>>>> + return 0;
>>>> +}
>>>>
>>>
>>> Look mom, I shrunk my patch! But I guess that was not intional...
>>
>> My dearest son, please have a closer look at path one.
>>
>> Rhymed-By: Ralf Ramsauer <[email protected]>
>>
>
> Even rhyming doesn't bring back inmates/demos/x86/cache-timings*.c to
> me... :)
Uarg, didn't notice. Happened during a rebase, locally those files were
existent so I didn't notice. Still, the Patch 1 of this series is
another than Patch 1 of the last series.
Next time I'll try it with a spell. Maybe that helps. :)
Ralf
>
> Jan
>
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