Received-SPF: pass (google.com: domain of linux-kernel+bounces-66930-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Precedence: bulk
MIME-Version: 1.0
References: <20240214170157.17530-1-osalvador@suse.de> <20240214170157.17530-4-osalvador@suse.de>
 <08a08ea2-6764-48af-8883-84639c732ce5@suse.cz>
In-Reply-To: <08a08ea2-6764-48af-8883-84639c732ce5@suse.cz>
From: Marco Elver <elver@google.com>
Date: Thu, 15 Feb 2024 13:52:16 +0100
Message-ID: <CANpmjNNuZQi4dc2eDaCZASBaHz98Qd+1663_Qhwru_5ZBAmXjg@mail.gmail.com>
Subject: Re: [PATCH v9 3/7] mm,page_owner: Maintain own list of stack_records structs
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>, Andrew Morton <akpm@linux-foundation.org>, 
	linux-kernel@vger.kernel.org, linux-mm@kvack.org, 
	Michal Hocko <mhocko@suse.com>, Andrey Konovalov <andreyknvl@gmail.com>, 
	Alexander Potapenko <glider@google.com>
Content-Type: text/plain; charset="UTF-8"

On Thu, 15 Feb 2024 at 11:55, Vlastimil Babka <vbabka@suse.cz> wrote:
>
> On 2/14/24 18:01, Oscar Salvador wrote:
> > page_owner needs to increment a stack_record refcount when a new allocation
> > occurs, and decrement it on a free operation.
> > In order to do that, we need to have a way to get a stack_record from a
> > handle.
> > Implement __stack_depot_get_stack_record() which just does that, and make
> > it public so page_owner can use it.
> >
> > Also, traversing all stackdepot buckets comes with its own complexity,
> > plus we would have to implement a way to mark only those stack_records
> > that were originated from page_owner, as those are the ones we are
> > interested in.
> > For that reason, page_owner maintains its own list of stack_records,
> > because traversing that list is faster than traversing all buckets
> > while keeping at the same time a low complexity.
> >
> > For now, add to stack_list only the stack_records of dummy_handle and
> > failure_handle, and set their refcount of 1.
> >
> > Further patches will add code to increment or decrement stack_records
> > count on allocation and free operation.
> >
> > Signed-off-by: Oscar Salvador <osalvador@suse.de>
>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
>

+1

Reviewed-by: Marco Elver <elver@google.com>