From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 092971FF7A5 for ; Tue, 4 Feb 2025 23:10:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738710643; cv=none; b=oYrbU6A7UZQzHIugq20C9VzZSbKSMyUJYEwpECJcfFQeGrZ6FjoJBQicu8kKTb1jOE9yRmur2oSV3TF7uzPQIw2b7eb8OZAiwEgmSj85DiAxOf9Ma3HK4bcsws6Gh+AYzwb0tgRshLcCO8UmlMYtQ0J61bwhdxWSZ9OwX0Q1Rkw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738710643; c=relaxed/simple; bh=GdHA7lLu4VS8qeX7AJ6pbGx/Uc8jEbD6HLfU9CeuGks=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LHlVNSRPSBEZifdBYN4sG+xvXI00/AmL4RgctqOme/z70cIsmviY241wIqsjtyzLF75T4pf0yf5eO1Al6o8BpHh09yOIlFXqRwTLwYFrIR2mxbDvQn85gWKNs0yRvPoiNJCi0h09LNu+HWmK+8bgFTr4X/O7ymQLDipx+3CMtMs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fF049Uud; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fF049Uud" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D267C4CEDF; Tue, 4 Feb 2025 23:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738710642; bh=GdHA7lLu4VS8qeX7AJ6pbGx/Uc8jEbD6HLfU9CeuGks=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fF049Uudk1DH95emQvgW8aS9CzUQrdM36b/gbXBjV5h+DfYQVEmd9q8pmmpHWXpdS Osit0JPvJASMiDxh+JiSJ1QLhhxbA7gL69eSiXp0oiA74sCuXJy0TyHRLvfKqJrVS+ 5vc9xjM8hfq2Hk429kjXvJaT594UNBn5fagIjwHw+TYYj3MzTOJRQpHMWWdzwiakhw HHuGfWMbtwQyipHUZN6xFt2hjC06+k4kBBpwVXKe2pgD1St70sbQ8DWZoykC52WTca 7S/f0lZOnneaNlZ/J9paDfw45qVS1qSKmp5BS0CdqedJuWVwQyZHOynmRT861/WeTH OiAuu+rwPSSKQ== From: SeongJae Park To: Usama Arif Cc: SeongJae Park , akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, hannes@cmpxchg.org, david@redhat.com, kernel-team@meta.com Subject: Re: [PATCH v4 3/6] mm/damon/sysfs-schemes: add files for setting damos_filter->folio_size Date: Tue, 4 Feb 2025 15:10:40 -0800 Message-Id: <20250204231040.2655-1-sj@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250203225604.44742-4-usamaarif642@gmail.com> References: Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Mon, 3 Feb 2025 22:55:30 +0000 Usama Arif wrote: > Add min and max files for damon filters to let the userspace decide > the min/max folio size to operate on. This will be needed to decide > what folio sizes to give pa_stat for. I'd prefer implementing the logic with API interface first, and then implementing sysfs interface on top of the API. > > Signed-off-by: Usama Arif > --- > include/linux/damon.h | 11 +++++++++ > mm/damon/core.c | 3 +++ > mm/damon/sysfs-schemes.c | 53 ++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 67 insertions(+) > > diff --git a/include/linux/damon.h b/include/linux/damon.h > index af525252b853..6f30ceeff215 100644 > --- a/include/linux/damon.h > +++ b/include/linux/damon.h > @@ -35,6 +35,16 @@ struct damon_addr_range { > unsigned long end; > }; > > +/** > + * struct damon_folio_size - Represents size of folio filter on [@min, @max]. > + * @min: Min size of the folio (inclusive). > + * @max: Max size of the folio (inclusive). > + */ > +struct damon_folio_size { > + unsigned long min; > + unsigned long max; > +}; > + I'd suggest giving a more general name, say, damon_size_range, so that we can reuse this for any possible future size range based filters or whatever. > /** > * struct damon_region - Represents a monitoring target region. > * @ar: The address range of the region. > @@ -377,6 +387,7 @@ struct damos_filter { > struct damon_addr_range addr_range; > int target_idx; > }; > + struct damon_folio_size folio_size; As this will be used depending on damos_filter->type, let's add this field in the above union, together with addr_range and target_idx. Also, I'd prefer calling this hugepage_size, as we discussed on the previous version of this patch series. > struct list_head list; > }; > > diff --git a/mm/damon/core.c b/mm/damon/core.c > index c7b981308862..27323e3a800d 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -776,6 +776,9 @@ static void damos_commit_filter_arg( > case DAMOS_FILTER_TYPE_TARGET: > dst->target_idx = src->target_idx; > break; > + case DAMOS_FILTER_TYPE_HUGEPAGE: > + dst->folio_size = src->folio_size; > + break; > default: > break; > } > diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c > index 98f93ae9f59e..bc7ca43ca9c4 100644 > --- a/mm/damon/sysfs-schemes.c > +++ b/mm/damon/sysfs-schemes.c > @@ -316,6 +316,7 @@ struct damon_sysfs_scheme_filter { > bool allow; > char *memcg_path; > struct damon_addr_range addr_range; > + struct damon_folio_size folio_size; Again, I'd prefer calling this hugepage_size. > int target_idx; > }; > > @@ -469,6 +470,43 @@ static ssize_t addr_end_store(struct kobject *kobj, > struct damon_sysfs_scheme_filter *filter = container_of(kobj, > struct damon_sysfs_scheme_filter, kobj); > int err = kstrtoul(buf, 0, &filter->addr_range.end); > + return err ? err : count; > +} Let's keep the blank line before 'return' so that this is not unnecessarily marked as a diff. > + > +static ssize_t min_show(struct kobject *kobj, > + struct kobj_attribute *attr, char *buf) > +{ > + struct damon_sysfs_scheme_filter *filter = container_of(kobj, > + struct damon_sysfs_scheme_filter, kobj); > + > + return sysfs_emit(buf, "%lu\n", filter->folio_size.min); > +} > + > +static ssize_t min_store(struct kobject *kobj, > + struct kobj_attribute *attr, const char *buf, size_t count) > +{ > + struct damon_sysfs_scheme_filter *filter = container_of(kobj, > + struct damon_sysfs_scheme_filter, kobj); > + int err = kstrtoul(buf, 0, &filter->folio_size.min); > + > + return err ? err : count; > +} > + > +static ssize_t max_show(struct kobject *kobj, > + struct kobj_attribute *attr, char *buf) > +{ > + struct damon_sysfs_scheme_filter *filter = container_of(kobj, > + struct damon_sysfs_scheme_filter, kobj); > + > + return sysfs_emit(buf, "%lu\n", filter->folio_size.max); > +} > + > +static ssize_t max_store(struct kobject *kobj, > + struct kobj_attribute *attr, const char *buf, size_t count) > +{ > + struct damon_sysfs_scheme_filter *filter = container_of(kobj, > + struct damon_sysfs_scheme_filter, kobj); > + int err = kstrtoul(buf, 0, &filter->folio_size.max); > > return err ? err : count; > } > @@ -519,6 +557,12 @@ static struct kobj_attribute damon_sysfs_scheme_filter_addr_start_attr = > static struct kobj_attribute damon_sysfs_scheme_filter_addr_end_attr = > __ATTR_RW_MODE(addr_end, 0600); > > +static struct kobj_attribute damon_sysfs_scheme_filter_min_attr = > + __ATTR_RW_MODE(min, 0600); > + > +static struct kobj_attribute damon_sysfs_scheme_filter_max_attr = > + __ATTR_RW_MODE(max, 0600); > + > static struct kobj_attribute damon_sysfs_scheme_filter_damon_target_idx_attr = > __ATTR_RW_MODE(damon_target_idx, 0600); > > @@ -529,6 +573,8 @@ static struct attribute *damon_sysfs_scheme_filter_attrs[] = { > &damon_sysfs_scheme_filter_memcg_path_attr.attr, > &damon_sysfs_scheme_filter_addr_start_attr.attr, > &damon_sysfs_scheme_filter_addr_end_attr.attr, > + &damon_sysfs_scheme_filter_min_attr.attr, > + &damon_sysfs_scheme_filter_max_attr.attr, > &damon_sysfs_scheme_filter_damon_target_idx_attr.attr, > NULL, > }; > @@ -1953,6 +1999,13 @@ static int damon_sysfs_add_scheme_filters(struct damos *scheme, > filter->addr_range = sysfs_filter->addr_range; > } else if (filter->type == DAMOS_FILTER_TYPE_TARGET) { > filter->target_idx = sysfs_filter->target_idx; > + } else if (filter->type == DAMOS_FILTER_TYPE_HUGEPAGE) { > + if (sysfs_filter->folio_size.min > > + sysfs_filter->folio_size.max) { > + damos_destroy_filter(filter); > + return -EINVAL; > + } I don't think letting users set invalid min/max is a real problem, as long as the implementation will handle the case (no memory matches the filter). Let's just allow it, like addr_range case. If we really need to disallow this, it would better to do that from damos_commit_filter() like central point. > + filter->folio_size = sysfs_filter->folio_size; > } > > damos_add_filter(scheme, filter); > -- > 2.43.5 Thanks, SJ