From 1059fb529114a4ac524e4c366f0a0933810efddf Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 3 Jul 2024 10:21:17 -0700 Subject: [PATCH] perf dsos: When adding a dso into sorted dsos maintain the sort order dsos__add would add at the end of the dso array possibly requiring a later find to re-sort the array. Patterns of find then add were becoming O(n*log n) due to the sorts. Change the add routine to be O(n) rather than O(1) but to maintain the sorted-ness of the dsos array so that later finds don't need the O(n*log n) sort. Fixes: 3f4ac23a9908 ("perf dsos: Switch backing storage to array from rbtree/list") Reported-by: Namhyung Kim Signed-off-by: Ian Rogers Cc: Steinar Gunderson Cc: Athira Rajeev Cc: Matt Fleming Link: https://lore.kernel.org/r/20240703172117.810918-3-irogers@google.com Signed-off-by: Namhyung Kim --- tools/perf/util/dsos.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index 5e5e05f86dd3..d4acdb37f046 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -206,11 +206,27 @@ int __dsos__add(struct dsos *dsos, struct dso *dso) dsos->dsos = temp; dsos->allocated = to_allocate; } - dsos->dsos[dsos->cnt++] = dso__get(dso); - if (dsos->cnt >= 2 && dsos->sorted) { - dsos->sorted = dsos__cmp_long_name_id_short_name(&dsos->dsos[dsos->cnt - 2], - &dsos->dsos[dsos->cnt - 1]) - <= 0; + if (!dsos->sorted) { + dsos->dsos[dsos->cnt++] = dso__get(dso); + } else { + int low = 0, high = dsos->cnt - 1; + int insert = dsos->cnt; /* Default to inserting at the end. */ + + while (low <= high) { + int mid = low + (high - low) / 2; + int cmp = dsos__cmp_long_name_id_short_name(&dsos->dsos[mid], &dso); + + if (cmp < 0) { + low = mid + 1; + } else { + high = mid - 1; + insert = mid; + } + } + memmove(&dsos->dsos[insert + 1], &dsos->dsos[insert], + (dsos->cnt - insert) * sizeof(struct dso *)); + dsos->cnt++; + dsos->dsos[insert] = dso__get(dso); } dso__set_dsos(dso, dsos); return 0;