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[73.219.103.14]) by smtp.gmail.com with ESMTPSA id e9-20020ac84e49000000b002f1fcda1ac7sm611180qtw.82.2022.04.19.13.32.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Apr 2022 13:32:10 -0700 (PDT) From: Kent Overstreet To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Cc: Kent Overstreet , roman.gushchin@linux.dev, hannes@cmpxchg.org Subject: [PATCH 0/4] Printbufs & shrinker OOM reporting Date: Tue, 19 Apr 2022 16:31:58 -0400 Message-Id: <20220419203202.2670193-1-kent.overstreet@gmail.com> X-Mailer: git-send-email 2.35.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Debugging OOMs has been one of my sources of frustration, so this patch series is an attempt to do something about it. The first patch in the series is something I've been slowly evolving in bcachefs for years: simple heap allocated strings meant for appending to and building up structured log/error messages. They make it easy and straightforward to write pretty-printers for everything, which in turn makes good logging and error messages something that just happens naturally. We want it here because that means the reporting I'm adding to shrinkers can be used by both OOM reporting, and for the sysfs (or is it debugfs now) interface that Roman is adding. This patch series also: - adds OOM reporting on shrinkers, reporting on top 10 shrinkers (in sorted order!) - changes slab reporting to be always-on, also reporting top 10 slabs in sorted order - starts centralizing OOM reporting in mm/show_mem.c The last patch in the series is only a demonstration of how to implement the shrinker .to_text() method, since bcachefs isn't upstream yet. Kent Overstreet (4): lib/printbuf: New data structure for heap-allocated strings mm: Add a .to_text() method for shrinkers mm: Centralize & improve oom reporting in show_mem.c bcachefs: shrinker.to_text() methods fs/bcachefs/btree_cache.c | 18 ++- fs/bcachefs/btree_key_cache.c | 18 ++- include/linux/printbuf.h | 140 ++++++++++++++++++ include/linux/shrinker.h | 5 + lib/Makefile | 4 +- lib/printbuf.c | 271 ++++++++++++++++++++++++++++++++++ mm/Makefile | 2 +- mm/oom_kill.c | 23 --- {lib => mm}/show_mem.c | 14 ++ mm/slab.h | 6 +- mm/slab_common.c | 53 ++++++- mm/vmscan.c | 75 ++++++++++ 12 files changed, 587 insertions(+), 42 deletions(-) create mode 100644 include/linux/printbuf.h create mode 100644 lib/printbuf.c rename {lib => mm}/show_mem.c (78%) -- 2.35.2