[PATCH] gitlab-ci: Decrease the size of the compiler cache

[Thomas Huth <thuth@redhat.com>]

From: Thomas Huth <thuth@redhat.com>

Uploading the cache from the runner takes a long time in the MSYS2
job, mostly due to the size of the compiler cache.
However, looking at runs with a non-initialized cache, and by doing
a "du -sh ." in the build directory, it seems like a build only
takes about 236 MiB of data, so the compiler cache with 500 MiB
certainly contains a lot of stale files. Thus decrease the size of
the ccache to a more reasonable value to speed up the MSYS2 job in
our CI (and add a "du -sh" at the end to have a reference for the
required cache size in the future).

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 Looking at the latest runs in the CI, our recent attempt to decrease
 the cache size by cleaning the pacman cache did not help much:
 https://gitlab.com/qemu-project/qemu/-/jobs/11747329283
 ... that run contains the "pacman -Sc" command, but the "Saving cache
 for successful job" step at the end still takes close to 20 minutes.
 So we likely have to shrink the compiler cache, too. In this run here:
 https://gitlab.com/thuth/qemu/-/jobs/11770708859#L1769
 I added a "du -sh" and you can see that the build directory only
 takes 236 MB there. So a ccache with the size of 250M should be
 sufficient for the MSYS2 job.

 .gitlab-ci.d/windows.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.gitlab-ci.d/windows.yml b/.gitlab-ci.d/windows.yml
index 6e1135d8b86..e2fef543899 100644
--- a/.gitlab-ci.d/windows.yml
+++ b/.gitlab-ci.d/windows.yml
@@ -94,7 +94,7 @@ msys2-64bit:
   - $env:MSYS = 'winsymlinks:native' # Enable native Windows symlink
   - $env:CCACHE_BASEDIR = "$env:CI_PROJECT_DIR"
   - $env:CCACHE_DIR = "$env:CCACHE_BASEDIR/ccache"
-  - $env:CCACHE_MAXSIZE = "500M"
+  - $env:CCACHE_MAXSIZE = "250M"
   - $env:CCACHE_DEPEND = 1 # cache misses are too expensive with preprocessor mode
   - $env:CC = "ccache gcc"
   - mkdir build
@@ -103,5 +103,6 @@ msys2-64bit:
   - ..\msys64\usr\bin\bash -lc "../configure $CONFIGURE_ARGS"
   - ..\msys64\usr\bin\bash -lc "make -j$env:JOBS"
   - ..\msys64\usr\bin\bash -lc "make check MTESTARGS='$TEST_ARGS' || { cat meson-logs/testlog.txt; exit 1; } ;"
+  - ..\msys64\usr\bin\bash -lc "du -sh ."
   - ..\msys64\usr\bin\bash -lc "ccache --show-stats"
   - Write-Output "Finished build at $(Get-Date -Format u)"
-- 
2.51.0