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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26B46C433FE for ; Wed, 20 Oct 2021 07:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02D9C60FD8 for ; Wed, 20 Oct 2021 07:21:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229836AbhJTHXo (ORCPT ); Wed, 20 Oct 2021 03:23:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:42888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229817AbhJTHXm (ORCPT ); Wed, 20 Oct 2021 03:23:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DCAAA60F59; Wed, 20 Oct 2021 07:21:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634714488; bh=ezv1SktQ7LD/gDQz+w7ted6/IJ4FUqR/RbIpQzSNSss=; h=From:To:Cc:Subject:Date:In-Reply-To:From; b=nYy80r1lxebC92cZLRYCmlA9rLJBxKP2RkbiPEo0BXfuYu3/+L5zFD/jiWyrgWL7N SsjKjMEzjCt3BNfoWFFP0UA9L4TMpJ37DVi3gGOdD8W/AWb0xvauWdod2FKJ8OVSNW 8jaHFf+rR0me9lrW9rRg36YfAMrngmBjHMM/nH5+yAVAiEhSlbiZZeEk/RVLg6lxq4 KYV4vGXzA1bee2RwK1215rNor1yxcJ1uGGStfnclfEbkuS0PzNyVGfrzYLMYPA+X78 TjD0EKUC557NPYSr007brCyr7FIn+5Pc4OWKe2k2gc+r0dmu9cWbFGneARPq4LvM5w GLB/z9ghN/zaA== From: SeongJae Park To: Xin Hao Cc: sjpark@amazon.de, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] mm/damon/dbgfs: Add adaptive_targets list check before enable monitor_on Date: Wed, 20 Oct 2021 07:21:21 +0000 Message-Id: <20211020072121.17166-1-sj@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 20 Oct 2021 09:42:33 +0800 Xin Hao wrote: > When the ctx->adaptive_targets list is empty, > I did some test on monitor_on interface like this. > > # echo > /sys/kernel/debug/damon/target_ids Thanks for the change, but you missed writing 'on' to 'monitor_on' in the above example. > > Though the ctx->adaptive_targets list is empty, but the > kthread_run still be called, and the kdamond.x thread still > be created, this is meaningless. > > So there adds a judgment in 'dbgfs_monitor_on_write', > if the ctx->adaptive_targets list is empty, return -EINVAL. > > Signed-off-by: Xin Hao Other parts looks good to me. However, seems this commit conflicts with a patch[1] which already merged in -mm tree. Could you please rebase this on it? FYI, all DAMON patches that merged in -mm tree are also applied on DAMON development tree. So, you could get the patch applied tree by: $ git remote add sj git://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git $ git fetch sj $ git checkout 0fa378d04b12 [1] https://lore.kernel.org/linux-mm/20211014073014.35754-1-sj@kernel.org/ Thanks, SJ > --- > include/linux/damon.h | 1 + > mm/damon/core.c | 5 +++++ > mm/damon/dbgfs.c | 13 ++++++++++--- > 3 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/include/linux/damon.h b/include/linux/damon.h > index 715dadd21f7c..4fce5f1f6dad 100644 > --- a/include/linux/damon.h > +++ b/include/linux/damon.h > @@ -316,6 +316,7 @@ void damon_destroy_scheme(struct damos *s); > > struct damon_target *damon_new_target(unsigned long id); > void damon_add_target(struct damon_ctx *ctx, struct damon_target *t); > +bool damon_targets_empty(struct damon_ctx *ctx); > void damon_free_target(struct damon_target *t); > void damon_destroy_target(struct damon_target *t); > unsigned int damon_nr_regions(struct damon_target *t); > diff --git a/mm/damon/core.c b/mm/damon/core.c > index 2f6785737902..c3a1374dbe0b 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -156,6 +156,11 @@ void damon_add_target(struct damon_ctx *ctx, struct damon_target *t) > list_add_tail(&t->list, &ctx->adaptive_targets); > } > > +bool damon_targets_empty(struct damon_ctx *ctx) > +{ > + return list_empty(&ctx->adaptive_targets); > +} > + > static void damon_del_target(struct damon_target *t) > { > list_del(&t->list); > diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c > index 38188347d8ab..9dee29f7d103 100644 > --- a/mm/damon/dbgfs.c > +++ b/mm/damon/dbgfs.c > @@ -865,12 +865,19 @@ static ssize_t dbgfs_monitor_on_write(struct file *file, > return -EINVAL; > } > > - if (!strncmp(kbuf, "on", count)) > + if (!strncmp(kbuf, "on", count)) { > + int i; > + > + for (i = 0; i < dbgfs_nr_ctxs; i++) { > + if (damon_targets_empty(dbgfs_ctxs[i])) > + return -EINVAL; > + } > err = damon_start(dbgfs_ctxs, dbgfs_nr_ctxs); > - else if (!strncmp(kbuf, "off", count)) > + } else if (!strncmp(kbuf, "off", count)) { > err = damon_stop(dbgfs_ctxs, dbgfs_nr_ctxs); > - else > + } else { > err = -EINVAL; > + } > > if (err) > ret = err; > -- > 2.31.0