[PATCH v2 0/2] Get callbacks/names of shrinkers from tracepoints

From: Janani Ravichandran
Date: Thu Aug 18 2016 - 01:35:41 EST


Currently, it is not possible to know which shrinkers are being run.
Even though the callbacks are printed using %pF in tracepoints
mm_shrink_slab_start and mm_shrink_slab_end, they are not visible to
userspace tools like perf.

To address this, this patchset
1. Enables the display of names of shrinker callbacks in tracepoints
mm_shrink_slab_start and mm_shrink_slab_end.
2. Adds a new tracepoint in the callback of the superblock shrinker to
get specific names of superblock types.

Changes since v1 at https://lkml.org/lkml/2016/7/9/33:
1. This patchset does not introduce a new variable to hold names of
shrinkers, unlike v1. It makes mm_shrink_slab_start and
mm_shrink_slab_end print names of callbacks instead.
2. It also adds a new tracepoint for superblock shrinkers to display
more specific name information, which v1 did not do.

Thanks to Dave Chinner and Tony Jones for their suggestions.

Janani Ravichandran (2):
include: trace: Display names of shrinker callbacks
fs: super.c: Add tracepoint to get name of superblock shrinker

fs/super.c | 2 ++
include/trace/events/vmscan.h | 39 +++++++++++++++++++++++++++++++++++++--
2 files changed, 39 insertions(+), 2 deletions(-)

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2.7.0