From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 64E5B606A326 for ; Thu, 29 Oct 2026 13:15:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=P1s8x4XE; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MmZFJDiu DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=lqh2h9OdAhEsv8R7JgV92DMgdxSdmNya/U3mKn63VeQ=; b=P1s8x4XEaR+bPWsHEvzH9JYqZQ mSvlTFHaolvIP+PV/gMyQVcbpN30V7igfe9N209CzlbZ7bLemerN8usl9JjquikE15Hgx+10tqoNE t0BwLbydvmX7Kz+XUSt5v853rf3COO75Y+hRLiiNefV87ayLRN/Mu4zMJ8ALZ23YjN1ZZtH4d9k4B JKUXVeutiCj61e5oo5lIVhHvGaxSGRAs2IcZRepcqRgxsMGhq9FiAyOERR2NlEY0xwp1kelKpTJmE WmAYhtePhevTR9OsIYMJjqaoP9vhR9/RjsLw4NRevR9FxJH/iQNNWOScciq+iku/4fCFg7oHwmdF3 FtFnA+mw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMPyu-00000009JxJ-3CUH; Thu, 29 Oct 2026 13:15:48 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMPys-00000009Jwz-3AKI for kexec@lists.infradead.org; Thu, 29 Oct 2026 13:15:46 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id DF0D6600D1; Thu, 29 Oct 2026 13:15:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A98C01F01825; Thu, 29 Oct 2026 13:15:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793279745; bh=lqh2h9OdAhEsv8R7JgV92DMgdxSdmNya/U3mKn63VeQ=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=MmZFJDiu5p0O+/D6H9EcM1bWgs2P1sLao6pof6JMiCUbkuDuhoUnWvIYq6wdOTfbm BpcdU9h8weFSI7YLOAuJPhsKw4Gi4YRQO5cUZN10fGi7ReIbYh9hagBT+jrYElX2YH +ih3xGMrA3kLoEpG35T95VY9VY8CZ9PitTQpY1G0Ri8tbgIY4OEyb5lujXrodMB0ht 9mq4mqJBN5iSIEzqMYOWBi7auC6ctfTuZZc8lG2Ic63rca7gBPiLKOXjhv0fOpMgDy ZaqKgfNBg3F6hiO66BQ6fFngZ+rT7A9j651kIkx8sefoDuBSSHj73PbusVG/D+GcyR U4/gnsox7yWQw== From: Pratyush Yadav To: Pasha Tatashin Cc: Pratyush Yadav , Alexander Viro , Christian Brauner , Jan Kara , "Matthew Wilcox (Oracle)" , Hugh Dickins , Baolin Wang , Andrew Morton , David Hildenbrand , Zi Yan , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Mike Rapoport , Matthew Brost , Joshua Hahn , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Kairui Song , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Johannes Weiner , Michal Hocko , Lorenzo Stoakes , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kexec@lists.infradead.org Subject: Re: [PATCH 1/3] mm/memfd_luo: don't use memfd_pin_folios() In-Reply-To: (Pasha Tatashin's message of "Wed, 28 Oct 2026 20:01:59 -0400") References: <20261027173031.763213-1-pratyush@kernel.org> <20261027173031.763213-2-pratyush@kernel.org> <179321872100.1775665.6881420026761127422.b4-review@b4> <2vxz4ie5o2ak.fsf@kernel.org> Date: Thu, 29 Oct 2026 14:15:38 +0100 Message-ID: <2vxzv76kmyv9.fsf@kernel.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" X-Spam-Status: No, score=-12.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Oct 28 2026, Pasha Tatashin wrote: > On 10-29 00:04, Pratyush Yadav wrote: >> > Nit: >> > >> > I would suggest adding another helper, memfd_luo_get_folio(inode, index, >> > &folio), that wraps: >> > >> > - shmem_get_folio() >> > - The !folio_is_longterm_pinnable() migration retry loop logic >> > >> > I think this would make the final code a bit more manageable. >> >> Sounds good, will do. >> >> > >> > Other than that the patch looks alright, feel free to add >> > Acked-by: Pasha Tatashin >> > Once the nit is addressed. >> >> Thanks! >> >> I think the MM side might take some time to gather reviews so I will >> send this out as part of a liveupdate-only series. This patch is useful >> on its own anyway. > > Sounds good. Could you also consider adding a patch to that live > update-only series to extend the memfd freeze from retrieve to finish()? > That would close another gap that does not affect us yet, but will once > other session fds depend on the memfd mapping. > > See: > https://lore.kernel.org/r/20261022225035.377445-8-dmatlack@google.com Hmm, right. That's a useful fix. I think I'll do that in a separate series, since it can go independently. -- Regards, Pratyush Yadav