From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C05783ED5A1; Mon, 17 Aug 2026 09:40:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786959634; cv=none; b=JsBHpUfJBMVcTtS97WVajJ2rJC/3WBNaRcWtrs3nrJFBCRMeC73CY29azjgYl87HrAClH52t4Fh0AxxxHAlt3nx6w5/4Y405VRK19eMgmkcqLZ9zUA9QCHY/Lc7FN52L9a9j2vn5c/qBp+4lxTfGwA1lBRPH4EVGkExSACJ1pRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786959634; c=relaxed/simple; bh=GT/8fHibs6AmaIZogwUwCSblkeJnPVW970lta4f2JIc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KS6GQy/4+9NijBVBNU3zyMbQar4r9RFfoWw8NkGER4DifnWy1T4IrkYqdXXtDTPV/4YpcwNLu6Z3ZzThTLDwuV864NWLoElxhhbeNnGr27zl7Q5IF3F6DpfJSEm+2FhAdybX5qO4IlTuwRRYlm3CcnMUWhW63drroCAri1m0fas= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XuWAFozN; arc=none smtp.client-ip=198.175.65.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XuWAFozN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1786959629; x=1818495629; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GT/8fHibs6AmaIZogwUwCSblkeJnPVW970lta4f2JIc=; b=XuWAFozN7xyRfmiZ1lLWxxfd1Cz41ycPVgTl7sO3aaK+/qBVEUsEJxjf ST/RmQ88z35jwCG3t96eBqhBApeKd01LJQDPw6xhfNg0u1t9mrKKhXQyR 6YiPRXCdxfZPIAE7IRYrtsbSS2BDF5aELML3a9JUEwxvxIcJve9uhUvU8 vcIGBYG+GHuWfiyiNKVuqrIpK+mEfpq+799wEnnjVPwDdJsOiNajaP2Kr DI7NieOhmSnJnNrX6dfBtXxMz23BRKIbXhkeXpP+AO6OqPYsiGidm46b8 mnMx12FRQFlBRDoFdIWX2G5bRum9neFu1BftkBJ+cweKa5v9+KCeW1Jyh Q==; X-CSE-ConnectionGUID: kmg1nBimQo2BBUFwJBO2cQ== X-CSE-MsgGUID: +2/LiHeCTvmjgmbL+V+Yzw== X-IronPort-AV: E=McAfee;i="6800,10657,11877"; a="98948188" X-IronPort-AV: E=Sophos;i="6.25,228,1779174000"; d="scan'208";a="98948188" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Aug 2026 02:40:28 -0700 X-CSE-ConnectionGUID: 3nL1zNn4QIigilsXNfvvZw== X-CSE-MsgGUID: l4ve1HVhSUiAj+vAZ/G7jg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,228,1779174000"; d="scan'208";a="288337226" Received: from linux-pnp-gnr-1.sh.intel.com ([10.239.83.186]) by fmviesa002.fm.intel.com with ESMTP; 17 Aug 2026 02:40:23 -0700 From: Jiebin Sun To: namhyung@kernel.org Cc: acme@kernel.org, mingo@redhat.com, peterz@infradead.org, adrian.hunter@intel.com, alexander.shishkin@linux.intel.com, irogers@google.com, james.clark@linaro.org, jolsa@kernel.org, mark.rutland@arm.com, dapeng1.mi@linux.intel.com, thomas.falcon@intel.com, tianyou.li@intel.com, wangyang.guo@intel.com, jiebin.sun@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 5/9] perf c2c: add function view stats merge and memory management Date: Mon, 17 Aug 2026 17:46:19 +0800 Message-ID: <20260817094623.3288456-6-jiebin.sun@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260817094623.3288456-1-jiebin.sun@intel.com> References: <20260817094623.3288456-1-jiebin.sun@intel.com> Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add the per-entry stats/cstats aggregation helpers and hierarchy teardown. Child common fields are released through hist_entry__delete(), while the function-view free callback handles the private child tree and containing allocation. Also add a helper for pruning writer entries with no stores or cacheline children. These are used by the entry-creation and builder patches that follow and are __maybe_unused until then. Signed-off-by: Jiebin Sun Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Dapeng Mi Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Falcon Reviewed-by: Tianyou Li Reviewed-by: Wangyang Guo --- tools/perf/util/c2c-function.c | 163 +++++++++++++++++++++++++++++++++ 1 file changed, 163 insertions(+) diff --git a/tools/perf/util/c2c-function.c b/tools/perf/util/c2c-function.c index d27544016660..aa6be7c72977 100644 --- a/tools/perf/util/c2c-function.c +++ b/tools/perf/util/c2c-function.c @@ -680,3 +680,166 @@ c2c_function_hists__reinit(struct c2c_hists *c2c_hists, return function_hpp_list__parse(&c2c_hists->list, output, sort, env); } + +/* Welford online merge of two "stats" (from util/stat.h) accumulators. */ +static void c2c_stats_merge(struct stats *dest, const struct stats *src) +{ + double delta; + + if (src->n == 0) + return; + + if (dest->n == 0) { + *dest = *src; + return; + } + + delta = src->mean - dest->mean; + dest->M2 += src->M2 + delta * delta * dest->n * src->n / (dest->n + src->n); + dest->mean = (dest->mean * dest->n + src->mean * src->n) / (dest->n + src->n); + dest->n += src->n; + + /* Update min/max */ + if (src->max > dest->max) + dest->max = src->max; + if (src->min < dest->min) + dest->min = src->min; +} + +/* Merge compute_stats during function aggregation. */ +static void __maybe_unused c2c_add_cstats(struct compute_stats *dest, + const struct compute_stats *src) +{ + c2c_stats_merge(&dest->rmt_hitm, &src->rmt_hitm); + c2c_stats_merge(&dest->lcl_hitm, &src->lcl_hitm); + c2c_stats_merge(&dest->rmt_peer, &src->rmt_peer); + c2c_stats_merge(&dest->lcl_peer, &src->lcl_peer); + c2c_stats_merge(&dest->load, &src->load); +} + +static bool __maybe_unused hist_entry__add_c2c_stats(struct hist_entry *he, + const struct c2c_stats *stats) +{ + u64 nr_events = c2c_hitm_count(stats) + stats->rmt_peer + stats->lcl_peer; + u64 weight1 = c2c_hitm_count(stats); + + /* + * Allocate before touching he->stat, so a failure here leaves the + * entry unmodified and the caller can bail out without having + * half-updated the statistics. + */ + if (symbol_conf.cumulate_callchain && !he->stat_acc) { + he->stat_acc = calloc(1, sizeof(struct he_stat)); + if (!he->stat_acc) + return false; + } + + he->stat.nr_events += nr_events; + he->stat.period += nr_events; + he->stat.weight1 += weight1; + + if (!symbol_conf.cumulate_callchain) + return true; + + he->stat_acc->nr_events += nr_events; + he->stat_acc->period += nr_events; + he->stat_acc->weight1 += weight1; + + return true; +} + +static void c2c_he__free_hierarchy(struct hist_entry *he); + +/* + * Free a function-view histogram entry (hist_entry_ops::free). + */ +static void __maybe_unused c2c_function_he_free(void *ptr) +{ + struct hist_entry *he = ptr; + struct c2c_hist_entry *c2c_he; + + c2c_he = container_of(he, struct c2c_hist_entry, he); + + if (c2c_he->hists) { + perf_hpp__reset_output_field(&c2c_he->hists->list); + hists__delete_all_entries(&c2c_he->hists->hists); + zfree(&c2c_he->hists); + } + + c2c_he__free_hierarchy(he); + + zfree(&c2c_he->nodeset); + zfree(&c2c_he->cpuset); + zfree(&c2c_he->nodestr); + zfree(&c2c_he->node_stats); + + free(c2c_he); +} + +static void c2c_he__free_hierarchy(struct hist_entry *he) +{ + struct rb_node *nd; + struct hist_entry *child_he; + + /* + * A leaf entry stores its callchains in the sorted_chain member, which + * shares a union with the hroot_in/hroot_out child trees, so its + * hroot_out is not a valid subtree to walk. Leaf entries never have a + * child hierarchy here, so stop before touching hroot_out. + */ + if (he->leaf) + return; + + if (RB_EMPTY_ROOT(&he->hroot_out.rb_root)) + return; + + nd = rb_first_cached(&he->hroot_out); + while (nd) { + struct rb_node *next = rb_next(nd); + + child_he = rb_entry(nd, struct hist_entry, rb_node); + rb_erase_cached(&child_he->rb_node, &he->hroot_out); + hist_entry__delete(child_he); + + nd = next; + } + + /* All children erased; clear the tree (and its cached leftmost). */ + he->hroot_out = RB_ROOT_CACHED; +} + +/* + * Drop level-2 writing functions that carry no stores or + * no cacheline children. Writers are only added when they store into a shared + * line, so this is mainly a safety net. Returns the number of surviving + * writers. + */ +static int __maybe_unused c2c_he__prune_empty_writers(struct hist_entry *l1_he) +{ + struct rb_node *nd; + int surviving = 0; + + if (!l1_he->has_children) + return 0; + + nd = rb_first_cached(&l1_he->hroot_out); + while (nd) { + struct rb_node *next = rb_next(nd); + struct hist_entry *l2_he = rb_entry(nd, struct hist_entry, rb_node); + + if (l2_he->has_children && hist_entry__displayed_stores(l2_he) > 0) { + surviving++; + } else { + rb_erase_cached(&l2_he->rb_node, &l1_he->hroot_out); + hist_entry__delete(l2_he); + } + nd = next; + } + + if (!surviving) { + l1_he->hroot_out = RB_ROOT_CACHED; + l1_he->has_children = false; + l1_he->unfolded = false; + } + return surviving; +} -- 2.52.0