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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 302EFC18E5B for ; Tue, 10 Mar 2020 09:00:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E6DDF2467F for ; Tue, 10 Mar 2020 09:00:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6DDF2467F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=Huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 81DEE6B0005; Tue, 10 Mar 2020 05:00:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7F4386B0006; Tue, 10 Mar 2020 05:00:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 70B336B0007; Tue, 10 Mar 2020 05:00:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 58B1B6B0005 for ; Tue, 10 Mar 2020 05:00:30 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 1376D181AEF00 for ; Tue, 10 Mar 2020 09:00:30 +0000 (UTC) X-FDA: 76578856620.26.beef94_78bb91d659131 X-HE-Tag: beef94_78bb91d659131 X-Filterd-Recvd-Size: 8340 Received: from huawei.com (lhrrgout.huawei.com [185.176.76.210]) by imf14.hostedemail.com (Postfix) with ESMTP for ; Tue, 10 Mar 2020 09:00:29 +0000 (UTC) Received: from lhreml709-cah.china.huawei.com (unknown [172.18.7.106]) by Forcepoint Email with ESMTP id 7486EDCB405AD658A72E; Tue, 10 Mar 2020 09:00:28 +0000 (GMT) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by lhreml709-cah.china.huawei.com (10.201.108.32) with Microsoft SMTP Server (TLS) id 14.3.408.0; Tue, 10 Mar 2020 09:00:27 +0000 Received: from localhost (10.202.226.57) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Tue, 10 Mar 2020 09:00:27 +0000 Date: Tue, 10 Mar 2020 09:00:26 +0000 From: Jonathan Cameron To: SeongJae Park CC: , SeongJae Park , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v6 04/14] mm/damon: Apply dynamic memory mapping changes Message-ID: <20200310090026.00005ea9@Huawei.com> In-Reply-To: <20200224123047.32506-5-sjpark@amazon.com> References: <20200224123047.32506-1-sjpark@amazon.com> <20200224123047.32506-5-sjpark@amazon.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.226.57] X-ClientProxiedBy: lhreml715-chm.china.huawei.com (10.201.108.66) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 24 Feb 2020 13:30:37 +0100 SeongJae Park wrote: > From: SeongJae Park > > Only a number of parts in the virtual address space of the processes is > mapped to physical memory and accessed. Thus, tracking the unmapped > address regions is just wasteful. However, tracking every memory > mapping change might incur an overhead. For the reason, DAMON applies > the dynamic memory mapping changes to the tracking regions only for each > of a user-specified time interval (``regions update interval``). > > Signed-off-by: SeongJae Park Trivial inline. Otherwise makes sense to me. > --- > mm/damon.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 95 insertions(+), 4 deletions(-) > > diff --git a/mm/damon.c b/mm/damon.c > index 1c8bb71bbce9..6a17408e83c2 100644 > --- a/mm/damon.c > +++ b/mm/damon.c > @@ -59,17 +59,22 @@ struct damon_task { > /* > * For each 'sample_interval', DAMON checks whether each region is accessed or > * not. It aggregates and keeps the access information (number of accesses to > - * each region) for each 'aggr_interval' time. > + * each region) for each 'aggr_interval' time. And for each > + * 'regions_update_interval', damon checks whether the memory mapping of the > + * target tasks has changed (e.g., by mmap() calls from the applications) and > + * applies the changes. > * > * All time intervals are in micro-seconds. > */ > struct damon_ctx { > unsigned long sample_interval; > unsigned long aggr_interval; > + unsigned long regions_update_interval; > unsigned long min_nr_regions; > unsigned long max_nr_regions; > > struct timespec64 last_aggregation; > + struct timespec64 last_regions_update; > > struct task_struct *kdamond; > bool kdamond_stop; > @@ -671,6 +676,87 @@ static void kdamond_split_regions(struct damon_ctx *ctx) > damon_split_regions_of(ctx, t); > } > > +/* > + * Check whether it is time to check and apply the dynamic mmap changes > + * > + * Returns true if it is. > + */ > +static bool kdamond_need_update_regions(struct damon_ctx *ctx) > +{ > + return damon_check_reset_time_interval(&ctx->last_regions_update, > + ctx->regions_update_interval); > +} > + > +static bool damon_intersect(struct damon_region *r, struct region *re) > +{ > + return !(r->vm_end <= re->start || re->end <= r->vm_start); > +} > + > +/* > + * Update damon regions for the three big regions of the given task > + * > + * t the given task > + * bregions the three big regions of the task > + */ > +static void damon_apply_three_regions(struct damon_ctx *ctx, > + struct damon_task *t, struct region bregions[3]) > +{ > + struct damon_region *r, *next; > + unsigned int i = 0; > + > + /* Remove regions which isn't in the three big regions now */ > + damon_for_each_region_safe(r, next, t) { > + for (i = 0; i < 3; i++) { > + if (damon_intersect(r, &bregions[i])) > + break; > + } > + if (i == 3) > + damon_destroy_region(r); > + } > + > + /* Adjust intersecting regions to fit with the threee big regions */ three > + for (i = 0; i < 3; i++) { > + struct damon_region *first = NULL, *last; > + struct damon_region *newr; > + struct region *br; > + > + br = &bregions[i]; > + /* Get the first and last regions which intersects with br */ > + damon_for_each_region(r, t) { > + if (damon_intersect(r, br)) { > + if (!first) > + first = r; > + last = r; > + } > + if (r->vm_start >= br->end) > + break; > + } > + if (!first) { > + /* no damon_region intersects with this big region */ > + newr = damon_new_region(ctx, br->start, br->end); > + damon_add_region(newr, damon_prev_region(r), r); > + } else { > + first->vm_start = br->start; > + last->vm_end = br->end; > + } > + } > +} > + > +/* > + * Update regions for current memory mappings > + */ > +static void kdamond_update_regions(struct damon_ctx *ctx) > +{ > + struct region three_regions[3]; > + struct damon_task *t; > + > + damon_for_each_task(ctx, t) { > + if (damon_three_regions_of(t, three_regions)) > + continue; > + damon_apply_three_regions(ctx, t, three_regions); > + } > +} > + > /* > * Check whether current monitoring should be stopped > * > @@ -735,6 +821,9 @@ static int kdamond_fn(void *data) > kdamond_split_regions(ctx); > } > > + if (kdamond_need_update_regions(ctx)) > + kdamond_update_regions(ctx); > + > usleep_range(ctx->sample_interval, ctx->sample_interval + 1); > } > damon_for_each_task(ctx, t) { > @@ -820,6 +909,7 @@ static int damon_set_pids(struct damon_ctx *ctx, > * > * sample_int time interval between samplings > * aggr_int time interval between aggregations > + * regions_update_int time interval between vma update checks > * min_nr_reg minimal number of regions > * max_nr_reg maximum number of regions > * > @@ -828,9 +918,9 @@ static int damon_set_pids(struct damon_ctx *ctx, > * > * Returns 0 on success, negative error code otherwise. > */ > -static int damon_set_attrs(struct damon_ctx *ctx, > - unsigned long sample_int, unsigned long aggr_int, > - unsigned long min_nr_reg, unsigned long max_nr_reg) > +static int damon_set_attrs(struct damon_ctx *ctx, unsigned long sample_int, > + unsigned long aggr_int, unsigned long regions_update_int, > + unsigned long min_nr_reg, unsigned long max_nr_reg) > { > if (min_nr_reg < 3) { > pr_err("min_nr_regions (%lu) should be bigger than 2\n", > @@ -845,6 +935,7 @@ static int damon_set_attrs(struct damon_ctx *ctx, > > ctx->sample_interval = sample_int; > ctx->aggr_interval = aggr_int; > + ctx->regions_update_interval = regions_update_int; > ctx->min_nr_regions = min_nr_reg; > ctx->max_nr_regions = max_nr_reg; > return 0;