| Message ID | 20230223001607.95523-1-andrealmeid@igalia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kbuild: modinst: Enable multithread xz compression | expand |
On Wed, Feb 22, 2023 at 09:16:07PM -0300, André Almeida wrote: > As it's done for zstd compression, enable multithread compression for > xz to speed up module installation. > > Signed-off-by: André Almeida <andrealmeid@igalia.com> This seems reasonable to me. Reviewed-by: Nathan Chancellor <nathan@kernel.org> If for some reason Masahiro does not want to take this, you could set XZ_OPT=-T0 in your build environment, which should accomplish the same thing. > --- > > On my setup xz is a bottleneck during module installation. Here are the > numbers to install it in a local directory, before and after this patch: > > $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > Executed in 100.08 secs > > $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > Executed in 28.60 secs > --- > scripts/Makefile.modinst | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst > index 4815a8e32227..28dcc523d2ee 100644 > --- a/scripts/Makefile.modinst > +++ b/scripts/Makefile.modinst > @@ -99,7 +99,7 @@ endif > quiet_cmd_gzip = GZIP $@ > cmd_gzip = $(KGZIP) -n -f $< > quiet_cmd_xz = XZ $@ > - cmd_xz = $(XZ) --lzma2=dict=2MiB -f $< > + cmd_xz = $(XZ) --lzma2=dict=2MiB -f -T0 $< > quiet_cmd_zstd = ZSTD $@ > cmd_zstd = $(ZSTD) -T0 --rm -f -q $< > > -- > 2.39.2 >
On Thu, Feb 23, 2023 at 9:17 AM André Almeida <andrealmeid@igalia.com> wrote: > > As it's done for zstd compression, enable multithread compression for > xz to speed up module installation. > > Signed-off-by: André Almeida <andrealmeid@igalia.com> > --- > > On my setup xz is a bottleneck during module installation. Here are the > numbers to install it in a local directory, before and after this patch: > > $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > Executed in 100.08 secs > > $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > Executed in 28.60 secs Heh, this is an interesting benchmark. Without this patch, you ran 16 processes of 'xz' in parallel since you gave -j16. You created multi-threads in each xz process, then you got 3x faster. What made it happen? How many threads can your system run? I did not get such an improvement in my testing. In my machine $(nproc) is 24. [Without this patch] $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) real 0m33.965s user 10m6.118s sys 0m37.231s [With this patch] $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) real 0m32.568s user 10m4.472s sys 0m39.132s Given that GNU Make provides the parallel execution environment, you can control the number of processes of 'xz'. There is no point in forcing multi-threading, which the user did not ask or ever want. > --- > scripts/Makefile.modinst | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst > index 4815a8e32227..28dcc523d2ee 100644 > --- a/scripts/Makefile.modinst > +++ b/scripts/Makefile.modinst > @@ -99,7 +99,7 @@ endif > quiet_cmd_gzip = GZIP $@ > cmd_gzip = $(KGZIP) -n -f $< > quiet_cmd_xz = XZ $@ > - cmd_xz = $(XZ) --lzma2=dict=2MiB -f $< > + cmd_xz = $(XZ) --lzma2=dict=2MiB -f -T0 $< > quiet_cmd_zstd = ZSTD $@ > cmd_zstd = $(ZSTD) -T0 --rm -f -q $< > > -- > 2.39.2 >
Hi Masahiro, Em 24/02/2023 02:38, Masahiro Yamada escreveu: > On Thu, Feb 23, 2023 at 9:17 AM André Almeida <andrealmeid@igalia.com> wrote: >> >> As it's done for zstd compression, enable multithread compression for >> xz to speed up module installation. >> >> Signed-off-by: André Almeida <andrealmeid@igalia.com> >> --- >> >> On my setup xz is a bottleneck during module installation. Here are the >> numbers to install it in a local directory, before and after this patch: >> >> $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 >> Executed in 100.08 secs >> >> $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 >> Executed in 28.60 secs > > > Heh, this is an interesting benchmark. > > Without this patch, you ran 16 processes of 'xz' in parallel > since you gave -j16. > > You created multi-threads in each xz process, then you got 3x faster. > What made it happen? > > During the modules installation in my setup, the build system would spend most of it's time compressing big modules (such as the 350M amdgpu.ko) in a single thread, with 15 idles threads. Enabling multithread allowed amdgpu to be compressed really fast. The real performance improvement during modules compression is not compressing as many small modules as possible in parallel, but compressing the big ones in multithread, that proved to be the bottleneck in my setup. > How many threads can your system run? $ nproc 16 > > I did not get such an improvement in my testing. > In my machine $(nproc) is 24. > > > [Without this patch] > > $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) > > real 0m33.965s > user 10m6.118s > sys 0m37.231s > > [With this patch] > > $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) > > real 0m32.568s > user 10m4.472s > sys 0m39.132s > > I can see that my patch did not introduce performance regressions to your setup, at least. > > Given that GNU Make provides the parallel execution environment, > you can control the number of processes of 'xz'. > > There is no point in forcing multi-threading, which the user > did not ask or ever want. > > Should we drop -T0 from zstd then? Is currently forcing multi-threading. > > > > > > > > > > > >> --- >> scripts/Makefile.modinst | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst >> index 4815a8e32227..28dcc523d2ee 100644 >> --- a/scripts/Makefile.modinst >> +++ b/scripts/Makefile.modinst >> @@ -99,7 +99,7 @@ endif >> quiet_cmd_gzip = GZIP $@ >> cmd_gzip = $(KGZIP) -n -f $< >> quiet_cmd_xz = XZ $@ >> - cmd_xz = $(XZ) --lzma2=dict=2MiB -f $< >> + cmd_xz = $(XZ) --lzma2=dict=2MiB -f -T0 $< >> quiet_cmd_zstd = ZSTD $@ >> cmd_zstd = $(ZSTD) -T0 --rm -f -q $< >> >> -- >> 2.39.2 >> > > Thanks, André Almeida
On Fri, Feb 24, 2023 at 9:13 PM André Almeida <andrealmeid@igalia.com> wrote: > > Hi Masahiro, > > Em 24/02/2023 02:38, Masahiro Yamada escreveu: > > On Thu, Feb 23, 2023 at 9:17 AM André Almeida <andrealmeid@igalia.com> wrote: > >> > >> As it's done for zstd compression, enable multithread compression for > >> xz to speed up module installation. > >> > >> Signed-off-by: André Almeida <andrealmeid@igalia.com> > >> --- > >> > >> On my setup xz is a bottleneck during module installation. Here are the > >> numbers to install it in a local directory, before and after this patch: > >> > >> $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > >> Executed in 100.08 secs > >> > >> $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 > >> Executed in 28.60 secs > > > > > > Heh, this is an interesting benchmark. > > > > Without this patch, you ran 16 processes of 'xz' in parallel > > since you gave -j16. > > > > You created multi-threads in each xz process, then you got 3x faster. > > What made it happen? > > > > > > During the modules installation in my setup, the build system would > spend most of it's time compressing big modules (such as the 350M > amdgpu.ko) in a single thread, with 15 idles threads. Enabling > multithread allowed amdgpu to be compressed really fast. It is a corner case, isn't it? amdgpu.ko appears early in modules.order. In most use-cases, other *.ko will fill the idle threads. xz(1) says Setting threads to a special value 0 makes xz use up to as many threads as the processor(s) on the system support. So, 'make -j$(nproc) modules_install' will have (nproc * nproc) threads at maximum. Of course, this is a theoretical calculation. The actual number of spawned threads will be much less, but spawning too many threads may not be nice. For your case, Nathan's suggestion will do. > > The real performance improvement during modules compression is not > compressing as many small modules as possible in parallel, but > compressing the big ones in multithread, that proved to be the > bottleneck in my setup. > > > How many threads can your system run? > > $ nproc > 16 > > > > > I did not get such an improvement in my testing. > > In my machine $(nproc) is 24. > > > > > > [Without this patch] > > > > $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) > > > > real 0m33.965s > > user 10m6.118s > > sys 0m37.231s > > > > [With this patch] > > > > $ time make INSTALL_MOD_PATH=/tmp/inst1 modules_install -j$(nproc) > > > > real 0m32.568s > > user 10m4.472s > > sys 0m39.132s > > > > > > I can see that my patch did not introduce performance regressions to > your setup, at least. > > > > > Given that GNU Make provides the parallel execution environment, > > you can control the number of processes of 'xz'. > > > > There is no point in forcing multi-threading, which the user > > did not ask or ever want. > > > > > > Should we drop -T0 from zstd then? Is currently forcing multi-threading. I think yes. -- Best Regards Masahiro Yamada
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst index 4815a8e32227..28dcc523d2ee 100644 --- a/scripts/Makefile.modinst +++ b/scripts/Makefile.modinst @@ -99,7 +99,7 @@ endif quiet_cmd_gzip = GZIP $@ cmd_gzip = $(KGZIP) -n -f $< quiet_cmd_xz = XZ $@ - cmd_xz = $(XZ) --lzma2=dict=2MiB -f $< + cmd_xz = $(XZ) --lzma2=dict=2MiB -f -T0 $< quiet_cmd_zstd = ZSTD $@ cmd_zstd = $(ZSTD) -T0 --rm -f -q $<
As it's done for zstd compression, enable multithread compression for xz to speed up module installation. Signed-off-by: André Almeida <andrealmeid@igalia.com> --- On my setup xz is a bottleneck during module installation. Here are the numbers to install it in a local directory, before and after this patch: $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 Executed in 100.08 secs $ time make INSTALL_MOD_PATH=/home/tonyk/codes/.kernel_deploy/ modules_install -j16 Executed in 28.60 secs --- scripts/Makefile.modinst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)