From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35FE9C76195 for ; Wed, 17 Jul 2019 20:25:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 18D0821880 for ; Wed, 17 Jul 2019 20:25:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728580AbfGQUZg (ORCPT ); Wed, 17 Jul 2019 16:25:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38366 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727104AbfGQUZe (ORCPT ); Wed, 17 Jul 2019 16:25:34 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C66030842A0; Wed, 17 Jul 2019 20:25:34 +0000 (UTC) Received: from llong.com (dhcp-17-160.bos.redhat.com [10.18.17.160]) by smtp.corp.redhat.com (Postfix) with ESMTP id AB95B5C260; Wed, 17 Jul 2019 20:25:31 +0000 (UTC) From: Waiman Long To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Roman Gushchin , Johannes Weiner , Shakeel Butt , Vladimir Davydov , Waiman Long Subject: [PATCH v2 2/2] mm, slab: Show last shrink time in us when slab/shrink is read Date: Wed, 17 Jul 2019 16:24:13 -0400 Message-Id: <20190717202413.13237-3-longman@redhat.com> In-Reply-To: <20190717202413.13237-1-longman@redhat.com> References: <20190717202413.13237-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Wed, 17 Jul 2019 20:25:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The show method of /sys/kernel/slab//shrink sysfs file currently returns nothing. This is now modified to show the time of the last cache shrink operation in us. CONFIG_SLUB_DEBUG depends on CONFIG_SYSFS. So the new shrink_us field is always available to the shrink methods. Signed-off-by: Waiman Long --- Documentation/ABI/testing/sysfs-kernel-slab | 2 ++ include/linux/slub_def.h | 1 + mm/slub.c | 12 +++++++++--- 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-kernel-slab b/Documentation/ABI/testing/sysfs-kernel-slab index 94ffd47fc8d7..9869a3f57dc3 100644 --- a/Documentation/ABI/testing/sysfs-kernel-slab +++ b/Documentation/ABI/testing/sysfs-kernel-slab @@ -437,6 +437,8 @@ Description: write for shrinking the cache. Other input values are considered invalid. If it is a root cache, all the child memcg caches will also be shrunk, if available. + When read, the time in us of the last cache shrink + operation is shown. What: /sys/kernel/slab/cache/slab_size Date: May 2007 diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index d2153789bd9f..055474197e83 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -113,6 +113,7 @@ struct kmem_cache { /* For propagation, maximum size of a stored attr */ unsigned int max_attr_size; #ifdef CONFIG_SYSFS + unsigned int shrink_us; /* Cache shrink time in us */ struct kset *memcg_kset; #endif #endif diff --git a/mm/slub.c b/mm/slub.c index 9736eb10dcb8..77d67a55ce43 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -34,6 +34,7 @@ #include #include #include +#include #include @@ -5287,16 +5288,21 @@ SLAB_ATTR(failslab); static ssize_t shrink_show(struct kmem_cache *s, char *buf) { - return 0; + return sprintf(buf, "%u\n", s->shrink_us); } static ssize_t shrink_store(struct kmem_cache *s, const char *buf, size_t length) { - if (buf[0] == '1') + if (buf[0] == '1') { + u64 start = sched_clock(); + kmem_cache_shrink_all(s); - else + s->shrink_us = (unsigned int)div_u64(sched_clock() - start, + NSEC_PER_USEC); + } else { return -EINVAL; + } return length; } SLAB_ATTR(shrink); -- 2.18.1