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Wed, 25 Feb 2026 13:06:46 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 25 Feb 2026 14:06:54 +0100 (CET) Date: Wed, 25 Feb 2026 14:06:45 +0100 From: Oleg Nesterov To: Pavel Tikhomirov Cc: Andrei Vagin , Christian Brauner , Shuah Khan , Kees Cook , Andrew Morton , David Hildenbrand , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Jan Kara , Aleksa Sarai , Andrei Vagin , Kirill Tkhai , Alexander Mikhalitsyn , Adrian Reber , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 2/4] pid: check init is created first after idr alloc Message-ID: References: <20260224164852.306583-1-ptikhomirov@virtuozzo.com> <20260224164852.306583-3-ptikhomirov@virtuozzo.com> <6269de34-203d-47b5-922b-342671573b7f@virtuozzo.com> MIME-Version: 1.0 In-Reply-To: <6269de34-203d-47b5-922b-342671573b7f@virtuozzo.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-MFC-PROC-ID: Py93sD_pugSTCPINLvlzImkCQoY8pebCPmaLTHnufDc_1772024836 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Stat-Signature: ecrm4ah4u83krixfbped8ugc4xnj1azh X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: BB5C01C0010 X-HE-Tag: 1772024849-688446 X-HE-Meta: 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 xmqbABeH 23vdYGxfw8pRP26JzSgu+hHT8ifaSoFsXWvKYnQmoC3K8LbCXsLV2uLOL8oJyeExn/EJp6GwltgcMewKE2TsQsiGeWv9uPiYVX0w1mbdEGD7/CV4V/skpiRylgot7beYGWAsiUzrfLxjUY3r3tTz50ajCtGU8LFR90dE+Dau+fqMW3pkgkONRplfKACaJCFOBH3+Tx8OgImq9NjElj9BOk+DXcPZmgHd8DgWfjPiZkGuuQvrMK0GS0hFCbY3LfZmyt/uns+Q3p2saH3u0MOS5mBdDEPrNna4BRJkULNAZzi0T9yPFGWQfW/FZDKwO9hcvFmyv+bMkGsHnj5w+m4RRIuFPu60OSWLppV6VpDt3dYsw4LWHKHAkPLa+iKqcBfo0kGTXpjQqpVIHcHIFJCP69/ze8g== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 02/25, Pavel Tikhomirov wrote: > > On 2/25/26 10:06, Oleg Nesterov wrote: > > On 02/24, Andrei Vagin wrote: > >> > >> I don't think this is an issue right now, as we only allow one attempt > >> to create the init. If that first attempt fails, free_pid will disable > >> further PID allocations in the target namespace. > > > > Thanks, you are right! > > I guess it means that we should change the commit message a bit, e.g.: replace > "Effectively leading ..." to "Though thanks to PIDNS_ADDING logic, free_pid() > disables further pid allocation in this case and it does not lead to any real > problem.". Agreed, > Please advise if I should resend the whole series (v4) for that? This is a question for Andrew ;) I guess you can just send a single [PATCH v4 2/4] in reply to v3, but it won't hurt if you resend the whole series. Oleg.