From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.238 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793695471; b=SEoT7p+93lzgLyQc+mdchH2TRNtynKD8PDjBLQYkAID33leKtrbuA/9ukRJiMZgNWjeP zC7xACJW40CUkuRqVcxHtISQCvGN3F4B+oHE35kBFJY8ZHCbvnE1CSilI+5pcLO52ONtM qMWEwH58RbeZqW6VK1QhoEDwO4j5UR4kUIDsUYTnfn/qZWJgcA/57FQR7nPyXlDqQAyq8 DgwWR4cR/U5jJW5SL8c7ZXc27LLid6Rvemdi1IuIb8wTFigVaRTQP17QzM0hwkrRoH5sv ShjuxnYEaXddNtpfky1Z37ob8vjjtfz41TBMpPpXJvHRMSABzgZM3wFeA2VWK/OosLA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793695471; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=ilisxbvbd8NSl3FqfuStr292wszm0PcMcOarGjNhaDU=; b=WC+DExJJipWCclA7q2WhxwpNUr7jUDGC74uPvBOu7HACf2xuU+9L+O4HDVzAQOmo7O9E tltb1HiOVrZyB5YAHZOqcplhaXptknS0vPiQ/E10sRU3/4LjLMF5srwWi642kNTxpXTuE kseit6qf8bSAZaJDhEkxn9Umt8YukysENHCDUq7AGSSTKWxS+sLdin4jTpHU7rGfkTcXQ 5N2c/PyNZ8A0nTVprOHoAHG9eVmT5sGvu3WLO1WIG7wKe8Kh5qK97ZssvTOQbS7lwn18L V0dYBvSPYGdqWbB00fBgBeSZfeDpV2KOjslD9vRQYFzQYOzmsSsfK+RWVENsfv2tdQQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=VgvQYUgS; arc=none smtp.remote-ip=91.218.175.238 Received: from mta0.migadu.com (out-238.mta0.migadu.com [91.218.175.238]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7FCA606D809 for ; Tue, 3 Nov 2026 08:44:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org D7FCA606D809 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=VgvQYUgS X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=XmvDp6Uab0sh7g6VkNQVO5JWlnHOPAP3vSfwuAggiUg=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793695468; v=1; x=1794300268; b=VgvQYUgSn9rJvn63grV0lQbWiRySyysEa4lJGYRUTt6r9Zr0ReglDaey6g/xwQgDVXtitFWJ KGKgRsrVEz28nKdTCWTFQnLaN6sKYUuoOkPgnanbmeqIrlrnvJAaD/VoVcI14T51pZ7tCeUn8xn seEDw49OCAJY7j2ukth3duxI= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 90c7e1b874827c5c; Tue, 03 Nov 2026 08:44:28 +0000 X-Mizu-Trace-ID: 90c7e1b874827c5c X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3901.200.71.1.16\)) Subject: Re: [PATCH 2/4] mm: hugetlb: skip CMA allocations under PF_MEMALLOC_PIN From: Muchun Song In-Reply-To: <5bc00742fe249cf09a3095abccf8889d5fa71116.1793692578.git.zhengqi.arch@bytedance.com> Date: Tue, 3 Nov 2026 16:44:10 +0800 Cc: osalvador@suse.de, david@kernel.org, akpm@linux-foundation.org, azpijr@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Qi Zheng , stable@vger.kernel.org Content-Transfer-Encoding: 7bit Message-Id: References: <5bc00742fe249cf09a3095abccf8889d5fa71116.1793692578.git.zhengqi.arch@bytedance.com> To: Qi Zheng X-Mailer: Apple Mail (2.3901.200.71.1.16) > On Nov 3, 2026, at 16:01, Qi Zheng wrote: > > From: Qi Zheng > > With gigantic overcommit enabled, a fault during long-term pinning > can allocate a fresh HugeTLB folio from CMA despite PF_MEMALLOC_PIN. > > The folio must then be migrated before it can be pinned. However, > fresh gigantic migration targets are not supported, so pinning fails > when the HugeTLB pool has no suitable target, even if the original > fault could have allocated pinnable memory outside CMA. > > Honor PF_MEMALLOC_PIN in the HugeTLB CMA allocator so the fault can > try the non-CMA fallback, or fail when allocation is restricted to CMA. > > Fixes: eb02f14c4a2b ("mm/hugetlb: allow overcommitting gigantic hugepages") > Cc: stable@vger.kernel.org > Signed-off-by: Qi Zheng LGTM. Acked-by: Muchun Song Thanks.