From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (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 C6F313F1AC8; Fri, 10 Jul 2026 08:43:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783672998; cv=none; b=AOxzqFIkd/wH7XEA0HSpop283w3ykOR5jbWXDnXZlU6tZsialiNGlPIYV2AuTTydiBeZNj81M8Th/PPNlbAe3yJ+ak6fTDoWCaRgovxFfQkuDoGiHHo1iS/MUEZTWHiwR0/HLt/nb6BEYRjBWtPtQxQiSxspZ6S1HDwF+N9pPKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783672998; c=relaxed/simple; bh=/c03sACpXNnDzjGc0BRBHbnCoiMBhDvHWXmtggqyd18=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Mltdi4qio/WFVsInfvfRyHcPKLDIJyxzApdFIqoPRjJW2M4yxK3O1jB8dMQOsrmqPbCn0rvVYBi6isvSG7eUAEiARCbxV1gWWARJg/sX5pheOrJ2hkb3jEch8BRCAjFPsiVPhKdqV6b7nev2MnanQ8z7ugeJ+rfdYo7ufUQuLBY= 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=FEbGiYl0; arc=none smtp.client-ip=198.175.65.17 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="FEbGiYl0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1783672996; x=1815208996; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=/c03sACpXNnDzjGc0BRBHbnCoiMBhDvHWXmtggqyd18=; b=FEbGiYl0gjEeagx0/KsOvnLo+UkC+TuQKlTcDg0mviY4u8wecDOdLSnk zQHrM7YLpkEQlLduMpIHu88UfxB+3gALJn7LKNoauy+QK4YZRxH/+Yfb+ fBAaP++D61LQ8BZxiPIkSoQ8h9IjVJ9LhXgzMlLxvEZm5h5oQGDSzJR3n aP9xvcrP1Yb1T2LLsMeqFz91slYG4LwZQ/JnMCIGe2uF0RmzmxDXOUos5 3x6J1iIqnTQwS4Epc6Gp3OeKJnC4iEHZ2MJ21BuMS1+xla+JokFcFHpuz rVvUMvIZZxASjgxfCIyGNYbEkMxV7kjeX7MtE/AGmMSh4tqui8u4cNAYI g==; X-CSE-ConnectionGUID: SJD7AV9MRYqud5MYwHZEYw== X-CSE-MsgGUID: cuuzhcgsTqquIauhJoEkgA== X-IronPort-AV: E=McAfee;i="6800,10657,11841"; a="84390859" X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="84390859" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2026 01:43:16 -0700 X-CSE-ConnectionGUID: z/F0LUASSdy6k9kj8F2Wdw== X-CSE-MsgGUID: 3IXcd4ehRJeZBA4hr8xrgA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="258435403" Received: from linux-pnp-gnr-1.sh.intel.com ([10.239.83.186]) by orviesa003.jf.intel.com with ESMTP; 10 Jul 2026 01:43:11 -0700 From: Jiebin Sun To: Namhyung Kim , Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra Cc: linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Jiebin Sun , Adrian Hunter , Alexander Shishkin , Dapeng Mi , Ian Rogers , James Clark , Jiri Olsa , Mark Rutland , Thomas Falcon , Tianyou Li , Wangyang Guo Subject: [PATCH v2 09/14] perf c2c: add stats merging and memory management helpers Date: Fri, 10 Jul 2026 16:42:42 +0800 Message-ID: <20260710084247.3576706-10-jiebin.sun@intel.com> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260710084247.3576706-1-jiebin.sun@intel.com> References: <20260626070355.1556721-1-jiebin.sun@intel.com> <20260710084247.3576706-1-jiebin.sun@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add statistics aggregation and memory management functions for function view histogram entries: Stats merging: - c2c_stats_merge(): combine two stats structs (Welford online merge) - c2c_add_cstats(): merge all compute_stats sub-fields - hist_entry__add_c2c_stats(): update hist_entry stat counters Memory management: - c2c_function_he_free(): free entry and recursively free children - c2c_he__free_hierarchy(): recursive cleanup of hroot_out tree Entry allocation reuses c2c_he_zalloc(), which was made shared via c2c.h in an earlier patch. These are used during hierarchy construction to allocate entries and aggregate C2C statistics across cacheline-function pairs. 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/ui/browsers/c2c-function.c | 158 ++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) diff --git a/tools/perf/ui/browsers/c2c-function.c b/tools/perf/ui/browsers/c2c-function.c index 0f21cf39f0ce..6afcb1e156c6 100644 --- a/tools/perf/ui/browsers/c2c-function.c +++ b/tools/perf/ui/browsers/c2c-function.c @@ -665,6 +665,164 @@ 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 __maybe_unused void 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 __maybe_unused bool 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); + + he->stat.nr_events += nr_events; + he->stat.period += nr_events; + he->stat.weight1 += weight1; + + if (!symbol_conf.cumulate_callchain) + return true; + + if (!he->stat_acc) { + he->stat_acc = calloc(1, sizeof(struct he_stat)); + if (!he->stat_acc) + return false; + } + + 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 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); +} + +/* + * Free all child entries under @he, recursively (hroot_out sub-tree). + * + * Children are built by c2c_child_entry__alloc(), which BORROWS thread and + * ms (plain copy, no thread__get()/map__get()) and OWNS only mem_info (a + * clone), stat_acc and the c2c-specific fields (hists, cpuset, nodeset, + * nodestr, node_stats). We therefore must NOT call hist_entry__delete() + * here: it would thread__zput()/map_symbol__exit() the borrowed refs and + * underflow their refcounts. Free exactly the owned resources instead. + */ +static void c2c_he__free_hierarchy(struct hist_entry *he) +{ + struct rb_node *nd; + struct hist_entry *child_he; + struct c2c_hist_entry *child_c2c; + + /* + * Leaf entries alias hroot_out with sorted_chain (callchains) in a + * union, so they have no child hierarchy to free here. + */ + 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); + child_c2c = container_of(child_he, struct c2c_hist_entry, he); + + if (child_he->stat_acc) + zfree(&child_he->stat_acc); + + if (child_he->mem_info) + mem_info__put(child_he->mem_info); + + if (child_c2c->hists) { + perf_hpp__reset_output_field(&child_c2c->hists->list); + hists__delete_all_entries(&child_c2c->hists->hists); + zfree(&child_c2c->hists); + } + + zfree(&child_c2c->cpuset); + zfree(&child_c2c->nodeset); + zfree(&child_c2c->nodestr); + zfree(&child_c2c->node_stats); + + c2c_he__free_hierarchy(child_he); + + rb_erase_cached(&child_he->rb_node, &he->hroot_out); + free(child_c2c); + + nd = next; + } + + /* All children erased; clear the tree (and its cached leftmost). */ + he->hroot_out = RB_ROOT_CACHED; +} + +/* Entry operations for function view */ +static struct hist_entry_ops c2c_function_entry_ops __maybe_unused = { + .new = c2c_he_zalloc, + .free = c2c_function_he_free, +}; + int perf_c2c__browse_function_view(struct hists *hists __maybe_unused) { ui__warning("C2C function view is not implemented yet.\n"); -- 2.52.0