Re: [PATCH v3 24/34] t/perf/p7519: speed up test using "test-tool touch"

> 
> On Thu, Jul 01 2021, Jeff Hostetler via GitGitGadget wrote:
> 
>> From: Jeff Hostetler <jeffhost@microsoft.com>
>>
>> Change p7519 to use a single "test-tool touch" command to update
>> the mtime on a series of (thousands) files instead of invoking
>> thousands of commands to update a single file.
>>
>> This is primarily for Windows where process creation is so
>> very slow and reduces the test run time by minutes.
>>
>> Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
>> ---
>>   t/perf/p7519-fsmonitor.sh | 14 ++++++--------
>>   1 file changed, 6 insertions(+), 8 deletions(-)
>>
>> diff --git a/t/perf/p7519-fsmonitor.sh b/t/perf/p7519-fsmonitor.sh
>> index 5eb5044a103..f74e6014a0a 100755
>> --- a/t/perf/p7519-fsmonitor.sh
>> +++ b/t/perf/p7519-fsmonitor.sh
>> @@ -119,10 +119,11 @@ test_expect_success "one time repo setup" '
>>   	fi &&
>>   
>>   	mkdir 1_file 10_files 100_files 1000_files 10000_files &&
>> -	for i in $(test_seq 1 10); do touch 10_files/$i; done &&
>> -	for i in $(test_seq 1 100); do touch 100_files/$i; done &&
>> -	for i in $(test_seq 1 1000); do touch 1000_files/$i; done &&
>> -	for i in $(test_seq 1 10000); do touch 10000_files/$i; done &&
>> +	test-tool touch sequence --pattern="10_files/%d" --start=1 --count=10 &&
>> +	test-tool touch sequence --pattern="100_files/%d" --start=1 --count=100 &&
>> +	test-tool touch sequence --pattern="1000_files/%d" --start=1 --count=1000 &&
>> +	test-tool touch sequence --pattern="10000_files/%d" --start=1 --count=10000 &&
>> +
>>   	git add 1_file 10_files 100_files 1000_files 10000_files &&
>>   	git commit -qm "Add files" &&
>>   
>> @@ -200,15 +201,12 @@ test_fsmonitor_suite() {
>>   	# Update the mtimes on upto 100k files to make status think
>>   	# that they are dirty.  For simplicity, omit any files with
>>   	# LFs (i.e. anything that ls-files thinks it needs to dquote).
>> -	# Then fully backslash-quote the paths to capture any
>> -	# whitespace so that they pass thru xargs properly.
>>   	#
>>   	test_perf_w_drop_caches "status (dirty) ($DESC)" '
>>   		git ls-files | \
>>   			head -100000 | \
>>   			grep -v \" | \
>> -			sed '\''s/\(.\)/\\\1/g'\'' | \
>> -			xargs test-tool chmtime -300 &&
>> +			test-tool touch stdin &&
>>   		git status
>>   	'
> 
> Did you try to replace this with some variant of:
> 
>      test_seq 1 10000 | xargs touch
> 
> Which (depending on your xargs version) would invoke "touch" commands
> with however many argv items it thinks you can handle.
>