From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f175.google.com (mail-pl1-f175.google.com [209.85.214.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E549C2EDD52 for ; Tue, 9 Sep 2025 14:16:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757427413; cv=none; b=Z8XqAp22VvmpT87WR6qfjmp/BoB/nLmj/z1t84rCGTfnWKL0/Tgilmr3mbZr453vD5r9SfsK4Rv37QPHSSG9vWZuwdPOjmizTgk/CaNT6vLjVgX63ofeLdtMAukwOX1fOdiaGj7KSlPDKIcfhDD8eNDqfVJuPQeDj8/wpQYKaN8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757427413; c=relaxed/simple; bh=o+VqiFi1ZuJKXK/R+K8Ffj0lVMmVJnNeQeEd17w/NPI=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=MipHS0eMZPB7O5VHlM/1fOzfg+K8Sz/+zcff8cyHA8P8zR4VjBe+U6Nc317R+McYqvtqTN2r46kNW5g1Sa59BnNGyQHFhlcIr1FqccYtxm9RWP5hv41hBMJ1/YTce/pu+sXOtkIvVUv5O4w9ucpYcGyjHzdnTGbMTkZitc8dOes= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ZZSLIy9Z; arc=none smtp.client-ip=209.85.214.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZZSLIy9Z" Received: by mail-pl1-f175.google.com with SMTP id d9443c01a7336-2518a38e7e4so35307055ad.1 for ; Tue, 09 Sep 2025 07:16:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1757427411; x=1758032211; darn=vger.kernel.org; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=TBPCbx1t1DtRFy/Qmvoz+7PpnPwODyvsfSiVPNyKvTQ=; b=ZZSLIy9ZcrR8UT488nV34k2lWSG2XAWhYoWMBQ4umwLUfSGZZoHPb0Oql7o0PRb/MR lwTexgiJSbpJS3Bi+PlPJExiAAE5Z3HkoL9a49cXFLDy6JUp3LWUO45u63f15jtNuIFH azKEZ6giBniPrJ4x7mHARtkx/+bIcfdITJ++YOp7tcd0SHExTKaX2l4hU0RXzu+32YJ3 4hNc45fQHxqqsrCH3FZAsodArEXEVDw3ct3do9jjhYyoDrQXPJZXKFB1FmxnGx+mtlps w9llkZ4CXVDLLh/1Mpxbaua/joOmEg0rQ0ucXdmSd309sGTvFR+rGVmKmMEBkesATcdZ F/KQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757427411; x=1758032211; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TBPCbx1t1DtRFy/Qmvoz+7PpnPwODyvsfSiVPNyKvTQ=; b=lpaySn6ooZRv7Es5BkZ+XStiSemUkNkP4N0xARDBBxXSAqnEk0ILLwgbw3HCNcGo5U EJHQoePF3Mo1/ECy3AGLazDbaiikP2elhXN2NI0NelcJZ3CtZMZd+EmYcoxVUFOMMNH7 cQKrD75jF3OHYeBNxBmB/ushYSyd9SvCpcE0s6J2ad1cq8VrhqsK34tWYx9t64O1oaat KyK8Uu8GgZSD8osDhs1H1rxTRxMs386mWlc+531hjYNvA5IoKi+rKJ/YGzXASqinL3HU o4vjeoqXnbmO8kM3VVfLXfKJaI8rAhsxLWHCH99mEkDmB/CgNmsVz20powUoJg5v3wlx pKGg== X-Forwarded-Encrypted: i=1; AJvYcCUIxNB1nS3rxjC4EoeKeHIdxWu2o7TusYkaq0jmWNiXp17Lex5RvqHHheh6rUr0A0JzOKQArfaJg3uelQg=@vger.kernel.org X-Gm-Message-State: AOJu0YwgHJZs+CkPWNp/I+Ll6telTQZPQga6tAZap9AZ6gOV1VUs74Gt F7WKWQjqRvA7j05ZEjf0aJ7G5tF0xVCCjxoKQBNkh/zsEGxoCBKAobFk X-Gm-Gg: ASbGncteZo/aC1ItVWQcIaA/ahaKWZ6dOyqH2g/XZzjo3qYqp1JrQZERiKdvpSMq+8Y 3JWWPPF8vaiMzb5Zwz9ASRRrZe0Q53aNZpf3sTmqLQeQ9N892jKjoxBR+hT64KNkBKf7bbQHWmb tEsR84D4PgMmzJZCsguyIDjUxGdwEz5PlDC/7syrWy6Pdm/CXzfRoiG6mXpOyzpAZzmWVQ3AQA/ CdCIJbm/RYf4zRIUSYejdMT9pH9kr9TjNfvKfyLLNo6D+PWSOuTwQPZCVLaEJYYNWMmEPYQy4K+ 9VIxi9kXHDZbF279l4RuDRVexBFKnjKYE5C8R8wdhRG7VanxtYWnaaHLixvzcJeUD9rX37lmIgh a/I2krxQkSBAciZQKNTgSaOkb7Uc8k4BCohrqDNYIIUobXmZCd7Q= X-Google-Smtp-Source: AGHT+IEnAyzLMxqnxsLrvjbSykcpJDqbEB5tk3wlxNjto04xhv0xpGQJTdUpv/FS+YKjD89GTMMNpQ== X-Received: by 2002:a17:902:f70f:b0:24d:34:b9e7 with SMTP id d9443c01a7336-24d0034be6cmr205718095ad.29.1757427410945; Tue, 09 Sep 2025 07:16:50 -0700 (PDT) Received: from smtpclient.apple ([39.144.103.165]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-24c9c2b12f9sm171757705ad.101.2025.09.09.07.16.47 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Sep 2025 07:16:50 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.700.81\)) Subject: Re: [PATCH] mm: shmem: fix too little space for tmpfs only fallback 4KB From: Vernon Yang In-Reply-To: <20250908162220.480d7014cc6c6ad2e14748c5@linux-foundation.org> Date: Tue, 9 Sep 2025 22:16:34 +0800 Cc: Vernon Yang , hughd@google.com, baolin.wang@linux.alibaba.com, da.gomez@samsung.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vernon Yang Content-Transfer-Encoding: 7bit Message-Id: <441CA7B5-4D1C-4334-AC1A-2CDA87530478@gmail.com> References: <20250908123128.900254-1-vernon2gm@gmail.com> <20250908162220.480d7014cc6c6ad2e14748c5@linux-foundation.org> To: Andrew Morton X-Mailer: Apple Mail (2.3826.700.81) > On Sep 9, 2025, at 07:22, Andrew Morton wrote: > > On Mon, 8 Sep 2025 20:31:28 +0800 Vernon Yang wrote: > >> From: Vernon Yang >> >> When the system memory is sufficient, allocating memory is always >> successful, but when tmpfs size is low (e.g. 1MB), it falls back >> directly from 2MB to 4KB, and other small granularity (8KB ~ 1024KB) >> will not be tried. >> >> Therefore add check whether the remaining space of tmpfs is sufficient >> for allocation. If there is too little space left, try smaller large >> folio. > > Thanks. > > What are the effects of this change? I'm assuming it's an > *improvement*, rather than a fix for some misbehavior? > When we use tmpfs and the tmpfs space is getting smaller and smaller (e.g. less than 2MB), it can still allocate 8KB~1MB large folio. Thank you for your feedback.