From nobody Sun Dec 28 22:52:31 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A753C46CA3 for ; Mon, 4 Dec 2023 23:49:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343519AbjLDXtS (ORCPT ); Mon, 4 Dec 2023 18:49:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234721AbjLDXtP (ORCPT ); Mon, 4 Dec 2023 18:49:15 -0500 Received: from 66-220-144-178.mail-mxout.facebook.com (66-220-144-178.mail-mxout.facebook.com [66.220.144.178]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFA6F101 for ; Mon, 4 Dec 2023 15:49:21 -0800 (PST) Received: by devbig1114.prn1.facebook.com (Postfix, from userid 425415) id EF772105D3A8A; Mon, 4 Dec 2023 15:49:09 -0800 (PST) From: Stefan Roesch To: kernel-team@fb.com Cc: shr@devkernel.io, akpm@linux-foundation.org, david@redhat.com, hannes@cmpxchg.org, riel@surriel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 3/4] mm/ksm: add tracepoint for ksm advisor Date: Mon, 4 Dec 2023 15:49:05 -0800 Message-Id: <20231204234906.1237478-4-shr@devkernel.io> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231204234906.1237478-1-shr@devkernel.io> References: <20231204234906.1237478-1-shr@devkernel.io> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This adds a new tracepoint for the ksm advisor. It reports the last scan time, the new setting of the pages_to_scan parameter and the average cpu percent usage of the ksmd background thread for the last scan. Signed-off-by: Stefan Roesch Acked-by: David Hildenbrand --- include/trace/events/ksm.h | 33 +++++++++++++++++++++++++++++++++ mm/ksm.c | 1 + 2 files changed, 34 insertions(+) diff --git a/include/trace/events/ksm.h b/include/trace/events/ksm.h index b5ac35c1d0e88..e728647b5d268 100644 --- a/include/trace/events/ksm.h +++ b/include/trace/events/ksm.h @@ -245,6 +245,39 @@ TRACE_EVENT(ksm_remove_rmap_item, __entry->pfn, __entry->rmap_item, __entry->mm) ); =20 +/** + * ksm_advisor - called after the advisor has run + * + * @scan_time: scan time in seconds + * @pages_to_scan: new pages_to_scan value + * @cpu_percent: cpu usage in percent + * + * Allows to trace the ksm advisor. + */ +TRACE_EVENT(ksm_advisor, + + TP_PROTO(s64 scan_time, unsigned long pages_to_scan, + unsigned int cpu_percent), + + TP_ARGS(scan_time, pages_to_scan, cpu_percent), + + TP_STRUCT__entry( + __field(s64, scan_time) + __field(unsigned long, pages_to_scan) + __field(unsigned int, cpu_percent) + ), + + TP_fast_assign( + __entry->scan_time =3D scan_time; + __entry->pages_to_scan =3D pages_to_scan; + __entry->cpu_percent =3D cpu_percent; + ), + + TP_printk("ksm scan time %lld pages_to_scan %lu cpu percent %u", + __entry->scan_time, __entry->pages_to_scan, + __entry->cpu_percent) +); + #endif /* _TRACE_KSM_H */ =20 /* This part must be outside protection */ diff --git a/mm/ksm.c b/mm/ksm.c index 18b7185bbc65b..b8065c5d5f833 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -455,6 +455,7 @@ static void scan_time_advisor(void) advisor_ctx.cpu_time =3D cpu_time; =20 ksm_thread_pages_to_scan =3D pages; + trace_ksm_advisor(scan_time, pages, cpu_percent); } =20 static void run_advisor(void) --=20 2.39.3