Subject: [PATCH 0/3] Improve store caching; improve 'map/accumulate-builds' performance

From: Ludovic Courtès <[email-masked]>
Date: Fri, 13 May 2022 16:59:47 +0200

Hello!

The first patch improves cache handling, providing a generic
way to trace caches.  The second patch adds a separate package/graft
cache, as was previously suggested in a comment.  The cache hit rate
can be seen by setting GUIX_PROFILING:

--8<---------------cut here---------------start------------->8---
$ time GUIX_PROFILING=package-graft-cache ./pre-inst-env guix home build -v1 -n ~/src/configuration/home-config.scm   
28.5 MB would be downloaded

Package Graft Cache:
  fresh caches:     1
  lookups:        794
  hits:           784 (98.7%)
  cache size:      10 entries

real	0m7.953s
user	0m9.091s
sys	0m0.291s
--8<---------------cut here---------------end--------------->8---

The last patch improves performance in the presence of grafts by trimming
exploration of the call tree in ‘map/accumulate-builds’.  This is very
much a heuristic, but it does help significantly for ‘guix system’,
‘guix home’, or ‘guix package’ with many packages.

Thoughts?

Ludo’.

Ludovic Courtès (3):
  store: 'mcached' users can specify a cache ID.
  packages: Use separate package/graft cache.
  store: Use a decaying cutoff in 'map/accumulate-builds'.

 guix/packages.scm |  12 ++++--
 guix/store.scm    | 104 +++++++++++++++++++++++++++++++++-------------
 2 files changed, 84 insertions(+), 32 deletions(-)

base-commit: 0b4300d4fd8c972f0cb9d6751fc824b9a065b780
-- 
2.36.0