<div dir='auto'>Ha, nice catch Mikulas!! Whew what a relief...<div dir="auto"> </div><div dir="auto">Joe: way to tip the scales in dm-cache's favor! :)</div></div><div class="gmail_extra"> <div class="gmail_quote">On Feb 5, 2020 4:17 AM, Mikulas Patocka <mpatocka@redhat.com> wrote: <blockquote class="quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Here I'm sending a patch for device mapper tests suite. With this patch, the cache is allocated on the fast device. It performs slightly better than dm-cache on the git-checkout benchmark: DM-CACHE git tests: SMQComparisonTests git_extract_only_across_cache_size_smq...formatting ... getting repo ... Elapsed 89.0716564: git_prepare Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 98.78236956: extract all versions Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 81.25339984: extract all versions Elapsed 271.27901308: cache size = 256, policy = smq formatting ... getting repo ... Elapsed 80.05892212: git_prepare Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 84.97932172: extract all versions DM-WRITECACHE git tests: Loaded suite writecache WriteCacheBenchmarks git_extract_only_across_cache_size...formatting ... getting repo ... Elapsed 81.97540516: git_prepare Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 79.58938916: extract all versions Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 73.42351832: extract all versions Elapsed 241.46500768: cache size = 256 formatting ... getting repo ... Elapsed 89.21745808: git_prepare Checking out v2.6.12 ... Checking out v2.6.13 ... Checking out v2.6.14 ... Elapsed 74.49628804: extract all versions From: Mikulas Patocka <mpatocka@redhat.com> Writecache tests used the slow device for both data and cache device - this resulted in horrible performance. This patch fixes it, so that the fast device is used for the cache. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> --- lib/dmtest/writecache-stack.rb | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) Index: device-mapper-test-suite/lib/dmtest/writecache-stack.rb =================================================================== --- device-mapper-test-suite.orig/lib/dmtest/writecache-stack.rb 2020-02-05 10:02:41.000000000 +0100 +++ device-mapper-test-suite/lib/dmtest/writecache-stack.rb 2020-02-05 10:02:41.000000000 +0100 @@ -29,14 +29,12 @@ class WriteCacheStack @cache = nil @opts = opts - #@tvm = TinyVolumeManager::VM.new - #@tvm.add_allocation_volume(ssd_dev) - #@tvm.add_volume(linear_vol('ssd', cache_size == :all ? @tvm.free_space : cache_size)) + @tvm = TinyVolumeManager::VM.new + @tvm.add_allocation_volume(ssd_dev) + @tvm.add_volume(linear_vol('ssd', cache_size == :all ? @tvm.free_space : cache_size)) @data_tvm = TinyVolumeManager::VM.new @data_tvm.add_allocation_volume(spindle_dev) - - @data_tvm.add_volume(linear_vol('ssd', cache_size == :all ? @tvm.free_space : cache_size)) @data_tvm.add_volume(linear_vol('origin', origin_size == :all ? @data_tvm.free_space : origin_size)) end @@ -53,7 +51,7 @@ class WriteCacheStack end def activate_support_devs(&block) - with_devs(@data_tvm.table('ssd'), + with_devs(@tvm.table('ssd'), @data_tvm.table('origin')) do |ssd, origin| @ssd = ssd @origin = origin @@ -71,7 +69,7 @@ class WriteCacheStack end def activate(&block) - with_devs(@data_tvm.table('ssd'), + with_devs(@tvm.table('ssd'), @data_tvm.table('origin')) do |ssd, origin| @ssd = ssd @origin = origin </blockquote></div> </div>