From: Pavel Begunkov <asml.silence@gmail.com>
To: Byungchul Park <byungchul@sk.com>
Cc: Mina Almasry <almasrymina@google.com>,
linux-mm@kvack.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel_team@skhynix.com,
harry.yoo@oracle.com, ast@kernel.org, daniel@iogearbox.net,
davem@davemloft.net, kuba@kernel.org, hawk@kernel.org,
john.fastabend@gmail.com, sdf@fomichev.me, saeedm@nvidia.com,
leon@kernel.org, tariqt@nvidia.com, mbloch@nvidia.com,
andrew+netdev@lunn.ch, edumazet@google.com, pabeni@redhat.com,
akpm@linux-foundation.org, david@redhat.com,
lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com,
vbabka@suse.cz, rppt@kernel.org, surenb@google.com,
mhocko@suse.com, horms@kernel.org, jackmanb@google.com,
hannes@cmpxchg.org, ziy@nvidia.com, ilias.apalodimas@linaro.org,
willy@infradead.org, brauner@kernel.org, kas@kernel.org,
yuzhao@google.com, usamaarif642@gmail.com,
baolin.wang@linux.alibaba.com, toke@redhat.com,
bpf@vger.kernel.org, linux-rdma@vger.kernel.org
Subject: Re: [PATCH v2] mm, page_pool: introduce a new page type for page pool in page type
Date: Tue, 29 Jul 2025 09:53:31 +0100 [thread overview]
Message-ID: <7d7eb3cd-db7e-4a9e-8671-4185b716bbc8@gmail.com> (raw)
In-Reply-To: <20250729010410.GC56089@system.software.com>
On 7/29/25 02:04, Byungchul Park wrote:
> On Mon, Jul 28, 2025 at 07:49:30PM +0100, Pavel Begunkov wrote:
>> On 7/28/25 19:39, Mina Almasry wrote:
>>> On Mon, Jul 28, 2025 at 11:35 AM Pavel Begunkov <asml.silence@gmail.com> wrote:
...>>> This may be my bad since I said we should check if it's 0 initialized.
>>>
>>> It looks like on the devmem side as well we kvmalloc_array the niovs,
>>> and if I'm checking through the helpers right, kvmalloc_array does
>>> 0-initialize indeed.
>>
>> I wouldn't rely on that, it's just for zcrx I do:
>>
>> kvmalloc_array(..., GFP_KERNEL | __GFP_ZERO);
>
> For net_devmem_bind_dmabuf(), __GFP_ZERO will add bigger overhead than
> just assignment, 'niov->pp = NULL'.
That's not a place where you should care about zeroing overhead.
> I'd like to ask you if you are still good with __GFP_ZERO overhead
> before going ahead.
However, it might be easier for you to just assign it directly
for devmem and let Mina add GFP_ZERO if he fancy the idea.
--
Pavel Begunkov
next prev parent reply other threads:[~2025-07-29 8:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-28 5:27 [PATCH v2] mm, page_pool: introduce a new page type for page pool in page type Byungchul Park
2025-07-28 8:20 ` [PATCH v2 rebase as of Jul 28] " Byungchul Park
2025-07-28 17:50 ` Mina Almasry
2025-07-28 8:45 ` [PATCH v2] " David Hildenbrand
2025-07-28 10:57 ` Byungchul Park
2025-07-28 18:36 ` Pavel Begunkov
2025-07-28 18:39 ` Mina Almasry
2025-07-28 18:49 ` Pavel Begunkov
2025-07-29 1:04 ` Byungchul Park
2025-07-29 8:53 ` Pavel Begunkov [this message]
2025-07-29 0:53 ` Byungchul Park
2025-07-29 0:51 ` Byungchul Park
2025-07-29 1:19 ` Byungchul Park
2025-07-29 9:22 ` Pavel Begunkov
2025-07-29 10:22 ` Byungchul Park
2025-07-31 6:13 ` Byungchul Park
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=7d7eb3cd-db7e-4a9e-8671-4185b716bbc8@gmail.com \
--to=asml.silence@gmail.com \
--cc=Liam.Howlett@oracle.com \
--cc=akpm@linux-foundation.org \
--cc=almasrymina@google.com \
--cc=andrew+netdev@lunn.ch \
--cc=ast@kernel.org \
--cc=baolin.wang@linux.alibaba.com \
--cc=bpf@vger.kernel.org \
--cc=brauner@kernel.org \
--cc=byungchul@sk.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=david@redhat.com \
--cc=edumazet@google.com \
--cc=hannes@cmpxchg.org \
--cc=harry.yoo@oracle.com \
--cc=hawk@kernel.org \
--cc=horms@kernel.org \
--cc=ilias.apalodimas@linaro.org \
--cc=jackmanb@google.com \
--cc=john.fastabend@gmail.com \
--cc=kas@kernel.org \
--cc=kernel_team@skhynix.com \
--cc=kuba@kernel.org \
--cc=leon@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-rdma@vger.kernel.org \
--cc=lorenzo.stoakes@oracle.com \
--cc=mbloch@nvidia.com \
--cc=mhocko@suse.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=rppt@kernel.org \
--cc=saeedm@nvidia.com \
--cc=sdf@fomichev.me \
--cc=surenb@google.com \
--cc=tariqt@nvidia.com \
--cc=toke@redhat.com \
--cc=usamaarif642@gmail.com \
--cc=vbabka@suse.cz \
--cc=willy@infradead.org \
--cc=yuzhao@google.com \
--cc=ziy@nvidia.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).