On Wed, 19 Aug 2026 00:05:35 -0700 Jason Miu <[email protected]> wrote:
> Background
> ==========
> Under severe system memory pressure, system unresponsiveness often
> occurs due to page allocation stalls. In commit 94e0bcde055e ("mm,
> page_alloc: reintroduce page allocation stall warning"), David Rientjes
> introduced a warning mechanism to emit a kernel log when a page
> allocation takes longer than 10 seconds. This log is used to correlate
> a frozen system with the system memory state at the time of failure.
>
> To further debug and analyze these allocation stalls, we need a
> reproducible test case. This patch series introduces a new selftest
> designed to artificially mimic the severe memory pressure scenarios
> seen in production, allowing us to observe the resulting allocation
> stalls.
Interesting.
> lib/Kconfig.debug | 11 +
> lib/Makefile | 1 +
> lib/test_mempress_timer.c | 140 +++++++++++
> .../testing/selftests/mm/page_alloc_stall.sh | 80 ++++++
> .../selftests/mm/page_alloc_stall_pressure.py | 235 ++++++++++++++++++
> 5 files changed, 467 insertions(+)
> create mode 100644 lib/test_mempress_timer.c
> create mode 100644 tools/testing/selftests/mm/page_alloc_stall.sh
> create mode 100644 tools/testing/selftests/mm/page_alloc_stall_pressure.py
Nothing fits very well, does it?
selftests is for quick tests which are run by run_kselftest.sh. You
had to place it in selftests because there isn't anywhere obvious for
it to live.
So I suggest a brand new tools/testing/stresstests/mm. If we create
this, people will jump on it and start adding things which presently
reside in their personal collections.
I can't say I like "mempress". Is "memory_pressure" too wordy?
All of lib/test*.c shouldn't be in lib/. lib/ is for library code!
Again, we put them there because people are shy about doing mkdir.
Sashiko said hello:
https://sashiko.dev/#/patchset/[email protected]
In [patch 1/3], s/__GFP_NOFAIL// and s/cond_resched()//.
