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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 758C3C433DF for ; Thu, 4 Jun 2020 07:27:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FED62077D for ; Thu, 4 Jun 2020 07:27:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="WnzST6NS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727938AbgFDH1G (ORCPT ); Thu, 4 Jun 2020 03:27:06 -0400 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:39602 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727916AbgFDH1F (ORCPT ); Thu, 4 Jun 2020 03:27:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1591255624; x=1622791624; h=from:to:cc:subject:date:message-id:in-reply-to: mime-version; bh=+aJnrbUqvIFf7ohzedUN3gFIX2zz4KmsEL9w8+oGKN4=; b=WnzST6NSZtPmoQZ4DcOQPA7mnUK2a7XFRjYsi/mRneofh6PyBWGbhxOt d+36W7kEEZmx4ed7s/ex0uKD2THxzb+212VahwvGxIinthhJZdnF7JpVB v1aCxPlBi1esF1TKDzFOlEKXzgmMDrePuwnVMwD+2Osc2D9u6kAOct+Cz U=; IronPort-SDR: J426QVX8oEfi7sc+ZPTlCCdn2WttshPkHh3eyOgQx47XJSmAizil8O2vjaFySFbrmJzpkfYb28 Pt2T5fDVQU2Q== X-IronPort-AV: E=Sophos;i="5.73,471,1583193600"; d="scan'208";a="34436999" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2a-e7be2041.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 04 Jun 2020 07:26:47 +0000 Received: from EX13MTAUEA002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2a-e7be2041.us-west-2.amazon.com (Postfix) with ESMTPS id 9A103A25A5; Thu, 4 Jun 2020 07:26:44 +0000 (UTC) Received: from EX13D31EUA001.ant.amazon.com (10.43.165.15) by EX13MTAUEA002.ant.amazon.com (10.43.61.77) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Jun 2020 07:26:44 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.162.53) by EX13D31EUA001.ant.amazon.com (10.43.165.15) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Jun 2020 07:26:26 +0000 From: SeongJae Park To: David Hildenbrand CC: SeongJae Park , , "SeongJae Park" , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: Re: [RFC v2 7/9] mm/damon: Implement callbacks for physical memory monitoring Date: Thu, 4 Jun 2020 09:26:11 +0200 Message-ID: <20200604072611.11049-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: (raw) MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.43.162.53] X-ClientProxiedBy: EX13D10UWA002.ant.amazon.com (10.43.160.228) To EX13D31EUA001.ant.amazon.com (10.43.165.15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 3 Jun 2020 18:09:21 +0200 David Hildenbrand wrote: > On 03.06.20 16:11, SeongJae Park wrote: > > From: SeongJae Park > > > > This commit implements the four callbacks (->init_target_regions, > > ->update_target_regions, ->prepare_access_check, and ->check_accesses) > > for the basic access monitoring of the physical memory address space. > > By setting the callback pointers to point those, users can easily > > monitor the accesses to the physical memory. > > > > Internally, it uses the PTE Accessed bit, as similar to that of the > > virtual memory support. Also, it supports only page frames that > > supported by idle page tracking. Acutally, most of the code is stollen > > from idle page tracking. Users who want to use other access check > > primitives and monitor the frames that not supported with this > > implementation could implement their own callbacks on their own. > > > > Signed-off-by: SeongJae Park > > --- > > include/linux/damon.h | 5 ++ > > mm/damon.c | 184 ++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 189 insertions(+) > > > > diff --git a/include/linux/damon.h b/include/linux/damon.h > > index 1a788bfd1b4e..f96503a532ea 100644 > > --- a/include/linux/damon.h > > +++ b/include/linux/damon.h > > @@ -216,6 +216,11 @@ void kdamond_update_vm_regions(struct damon_ctx *ctx); > > void kdamond_prepare_vm_access_checks(struct damon_ctx *ctx); > > unsigned int kdamond_check_vm_accesses(struct damon_ctx *ctx); > > > > +void kdamond_init_phys_regions(struct damon_ctx *ctx); > > +void kdamond_update_phys_regions(struct damon_ctx *ctx); > > +void kdamond_prepare_phys_access_checks(struct damon_ctx *ctx); > > +unsigned int kdamond_check_phys_accesses(struct damon_ctx *ctx); > > + > > int damon_set_pids(struct damon_ctx *ctx, int *pids, ssize_t nr_pids); > > int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int, > > unsigned long aggr_int, unsigned long regions_update_int, > > diff --git a/mm/damon.c b/mm/damon.c > > index f5cbc97a3bbc..6a5c6d540580 100644 > > --- a/mm/damon.c > > +++ b/mm/damon.c > > @@ -19,7 +19,9 @@ > > #include > > #include > > #include > > +#include > > #include > > +#include > > #include > > #include > > #include > > @@ -480,6 +482,11 @@ void kdamond_init_vm_regions(struct damon_ctx *ctx) > > } > > } > > > > +/* Do nothing. Users should set the initial regions by themselves */ > > +void kdamond_init_phys_regions(struct damon_ctx *ctx) > > +{ > > +} > > + > > static void damon_mkold(struct mm_struct *mm, unsigned long addr) > > { > > pte_t *pte = NULL; > > @@ -611,6 +618,178 @@ unsigned int kdamond_check_vm_accesses(struct damon_ctx *ctx) > > return max_nr_accesses; > > } > > > > +/* access check functions for physical address based regions */ > > + > > +/* This code is stollen from page_idle.c */ > > +static struct page *damon_phys_get_page(unsigned long pfn) > > +{ > > + struct page *page; > > + pg_data_t *pgdat; > > + > > + if (!pfn_valid(pfn)) > > + return NULL; > > + > > Who provides these pfns? Can these be random pfns, supplied unchecked by > user space? Or are they at least mapped into some user space process? Your guess is right, users can give random physical address and that will be translated into pfn. > > IOW, do we need a pfn_to_online_page() to make sure the memmap even was > initialized? Thank you for pointing out this! I will use it in the next spin. Also, this code is stollen from page_idle_get_page(). Seems like it should also be modified to use it. I will send the patch for it, either. Thanks, SeongJae Park > > -- > Thanks, > > David / dhildenb