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bh=7gpeX2+OCbIxc12i2mYZPsdcMfJTSqmx3ZrRkkdCM+4=; b=zF1c8QGbLY/0E7FLUJ3jbKfeMDEyyD4ksmTkCBOGYKU1/pvdxb7BQzlBlOwYIufmMsTeBT IaAlRdA6jFdmV/xfc6nAQ4niumgJsWBu42fuuEYTgyAJkH08UI97x9V4I1Nj3HYo1hB4Tz HLJ5p22lZH1p95Rh0aAUoLZHno4ODBM= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=LCvUZwNn; spf=pass (imf19.hostedemail.com: domain of akpm@linux-foundation.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id CF75D601CA; Thu, 2 Jul 2026 22:03:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BEE41F000E9; Thu, 2 Jul 2026 22:03:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783029830; bh=7gpeX2+OCbIxc12i2mYZPsdcMfJTSqmx3ZrRkkdCM+4=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=LCvUZwNnVrM2HNgsSPkoUmu830cGdvN7ppa4NBCYDDqZ/QdSrKlIm2Q5Hx3LKfZ7T 84W0oQPg+pqDk9ZTIzx0YN+n8abBhwe5AStbXHu54vtFuicY3XpNwqNEN1mCycx/D4 xKshI9yvWQg+6sD1VsWKkpX5wEn4Z+KtYLvuVJp0= Date: Thu, 2 Jul 2026 15:03:49 -0700 From: Andrew Morton To: ackerleytng@google.com Cc: Ackerley Tng via B4 Relay , Muchun Song , Oscar Salvador , David Hildenbrand , fvdl@google.com, jiaqiyan@google.com, joshua.hahnjy@gmail.com, jthoughton@google.com, mhocko@kernel.org, michael.roth@amd.com, pasha.tatashin@soleen.com, pbonzini@redhat.com, peterx@redhat.com, pratyush@kernel.org, rick.p.edgecombe@intel.com, rientjes@google.com, roman.gushchin@linux.dev, seanjc@google.com, shakeel.butt@linux.dev, shivankg@amd.com, vannapurve@google.com, yan.y.zhao@intel.com, Zi Yan , Matthew Brost , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Dan Williams , Jason Gunthorpe , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 5/6] mm: hugetlb: Move mem_cgroup_charge_hugetlb() earlier in allocation Message-Id: <20260702150349.1aa99d5a0ecca8fecc07ffdf@linux-foundation.org> In-Reply-To: <20260702-hugetlb-open-up-v4-5-d53cefcccf34@google.com> References: <20260702-hugetlb-open-up-v4-0-d53cefcccf34@google.com> <20260702-hugetlb-open-up-v4-5-d53cefcccf34@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: BD77A1A0006 X-Stat-Signature: ert83e1t9mrenydfctcbfnstfz5osgdh X-Rspam-User: X-HE-Tag: 1783029837-466211 X-HE-Meta: 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 Iy8MI/hU hEyq3rFVW0+IC3GxwZ83+oe3xHKo7evsN+QLBQTON7AOrqKC90WmKNdNNsWQyS9mqmCD7t1RYwMpVDv8n4/f4l5Qf+b2EiYExxI/dNoXUxUFvszRBN36sR1b50XybBNGyAXm0I5inIyqdOd/vZUdeGPfxYiFKIBEFkAuEkuTCk6s1VYG7gBpSFdXTDaUc4RbYahLX1TKq+guSX3slAZIDaojtsQfJZKJbqMUDQHiP3Sl2N50obggghoYDXcGQWgPN6bk3HnLI2hbS0+P/TfcZvRcmY0AWXsy6Z6NFqW8vIiXOsuItRmclG0B3bsp5WaZQEhgTzWlYQz5gAcuyWEQHJuRHDx9rqR1uIxDOZAbL9dS5C1JMtpEUecqM4cYJ9ClheOwOlShyM3RLYn9sYJ+BLi20L/AKcK3E2wJHdvH3Mn1258VZeMqtvQNZY3QcIrKA/w+suEIXrr9FW+Q= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 02 Jul 2026 09:21:49 -0700 Ackerley Tng via B4 Relay wrote: > Move mem_cgroup_charge_hugetlb() earlier in the folio allocation > process. This change draws a cleaner line between memcg charging and the > subsequent hugetlb-specific reservation logic for VMAs and subpools. > > While it would be ideal to make all accounting and reservations perfectly > symmetric, mem_cgroup_charge_hugetlb() is a complex operation that cannot > be performed under the hugetlb_lock. Moving the charge to this earlier > point ensures that memcg charging is handled before the code begins > manipulating subpool and VMA-specific state. These two types of accounting > will be separated in a future patch. > > If mem_cgroup_charge_hugetlb() fails, the code now branches to > out_subpool_put to ensure the folio is freed and the subpool references are > handled correctly. Is this patch also "No functional change intended"?