From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f43.google.com (mail-ed1-f43.google.com [209.85.208.43]) (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 717ED36F915 for ; Thu, 27 Aug 2026 17:38:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=209.85.208.43 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787852281; cv=pass; b=JeI7+7vSCH+iOrNN/vL8zJRV9TQ02Qhahm0vhAr1OJGNKn7VpaVTm/h86w+PsMbGRws8GnoJvlp01kgD8WHFa6WV/qNedExdw7jEqfW/S/vgxTo1PlkDspjvBv4z9G8SIcxoq4EQ+TQtMNjJoIaFOoE5S0LVGzaA9gPoK56WEhw= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787852281; c=relaxed/simple; bh=6ex3kovo0uNMrsiAnnka/VhNOgHQ4ndsnxBahUyagcY=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=pwY9hTTUHES00lbHu2o5gvMKudwQGW64lXuf4uWy1jmwFESG1V0gnabEwXl32YqpWpTtQ8xo3YQphHg9Djobq80IRXBOU9CnCO3Odwu/kX9QjOkemVgbk74PjX4qaYcusNT4gq/shzMmWNHJ47J4kXCUnlrKmyGecDajwaMGK2k= ARC-Authentication-Results:i=2; 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=dmDlnspH; arc=pass smtp.client-ip=209.85.208.43 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="dmDlnspH" Received: by mail-ed1-f43.google.com with SMTP id 4fb4d7f45d1cf-6a38098734bso94889a12.1 for ; Thu, 27 Aug 2026 10:38:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1787852279; cv=none; d=google.com; s=arc-20260327; b=KSs+GfecpBp5iEj9PGY20XrszuUzGYqP4vzV5/UBPgMqT3QyuX3qkG0Sm80Hmqbe7k H4cw30Netj03cPvN43oGlnU1Ign6moeACb2tVy/8Rt/olKn8rSOOm6z4CYNLeYr17yCj udcJthtscKWzIf7QO0EHFiL2lPkya4bFMNzSEGxBDuja8j9y3Ah12rBZJaMChMxN5cyS RF3rA852wZMcw7yP2oFc5mlKazQ/kxUI/K0VOWfnG3XDcG6lW2ERkmB9u0rBJc700Mqx 2fjCzuOft/K0OVSEx60D0+22aooeCaTsTVCgZwzviDKH/DBqHWtIxwzoR4SHp4/arGB3 KmAg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20260327; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=kPHaEe57cuLcNj926FYE8F74J4KSg+lREB21aJh7hOA=; fh=Jk1DGrn6N74RlzinPvp0SiiCqa1pQlF4M96bNraEG5Y=; b=U64QwfaH+fGJ0JsWutJFIrj/LIkNc+lQti+2OjAHaozdq285sXzaxEgJaJ2CfIXP/y bpFcOQoQbOoCJXNTm9HF8TLP0k9+Lqwd1yQROfSfLTtt3H80t7vlQriBxGdnrnx5K6T0 aWpiFk3tPJM8LbjhsVtVsynAr2sL4EEkFZh9+AVgugUQfTGicfpv1TX2cXjuIIN8mb0d 8blyk7unsRVx6+a1iq7HdBuGkA1m6OqmF4Mk0j7b7fVec1OwVIorHsMGEK7OHI/KAZS0 YY3hufnKJvG48ctarJQnFbNPIoC96ktDGJPQyexAoDY41/P0j+ZtE+F0gj8riXWK1/yA efYA==; darn=vger.kernel.org ARC-Authentication-Results: i=1; mx.google.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1787852279; x=1788457079; darn=vger.kernel.org; h=content-transfer-encoding:content-type:cc:to:subject:message-id :date:from:in-reply-to:references:mime-version:from:to:cc:subject :date:message-id:reply-to:content-type; bh=kPHaEe57cuLcNj926FYE8F74J4KSg+lREB21aJh7hOA=; b=dmDlnspHSxVU9eFYABJs3fIjmj691zdfgRpAJbFMWaQF6LSBBPoq9LytqeunL+0chC BtYmWwwdvf15E4d0vzS4/XUt2NBitwTl4+RiTAC7pSgLGKb6mIAZ7R61blvj1tEl3ekO mIbZwQkkH043nlkr6St0uYjbZTKvchY1qa0Cvhn6s7MzPSCzPGJg4zmdZZRh6ElyRNK/ CrIuUiKQ69kR4wiiIT25tCdMnfJSYhjDnytMNBGz8X7JoHGTmDItBZ2YtrXORhAIPHtd RW3htk5KL4+vW/6L74cSH3Bn0sPmydQ9kFvyXuKl8cE8WRt1U+S1KXGZaXZDwxrCoG33 rq/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787852279; x=1788457079; h=content-transfer-encoding:content-type:cc:to:subject:message-id :date:from:in-reply-to:references:mime-version:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=kPHaEe57cuLcNj926FYE8F74J4KSg+lREB21aJh7hOA=; b=eUjpIL/Vv2XTGp6s+n/UBhSJjx5W/qcwP4tbazuXWFqGQhXIqwvYCoV/eGEQbJPlcu ABVV3AwA5U+B+tMJD/+0q2adlWHdisy1eN83lJWDU0+XvL3h0Bx0Qc0nuLAH0NNyK9sG PfT/dwokm8NiLx7EdqVZjOHKY4sz50TLF6DJYQ2n84N5Q/RFJPQ2fP/85VZLXRnmGPd8 nNHKrcCl9W2lIE0X3vYA7z2t6bj6bYB11ON242Dq6o59Ar//+MTo2CyVpUWojgVaXwiH geKqMlN3GDEIn/iYxuHnvUPPFXTL6AXB9PxmCFph2UzyCiPpYrsULKL5XZ6VSaotYvdL XaZg== X-Forwarded-Encrypted: i=1; AHgh+Rp4fEFHQzLo2TmEFf2u9TLVoddani2gjwskmg43LbI/oO3yxCWaXb6HJy0adB2FWrDnt3pUf2gQpQ3djLU=@vger.kernel.org X-Gm-Message-State: AFuF++n1pI7SQGX8Q5z5Nc04Xx6aQmu+JdLODkWKwMgeq4d+BK9nRR9M HhdfceyjA6kEpC2KOiCf7rgKYBmZA9vZQlZQB91Cog8lo4WqbJXBPg4D0Vli3gon67Ubpqz/nUm g74kS7MS0WX2iWd+POJ6ScOox5UYRNys= X-Gm-Gg: AR+sD10tVzTx8l9lwHBn3JcyKWTeBcxDuGktq3HzLgjLAOSTMmr3cboVnfujFMYN+Wn PcY7YEF/dCAmM9HnldD2Ku+rYYAgj9GZWLuXPGWsHHHgiNcOkZJEFHyjFubgUpsbFoQQIqIjRMG ZhJ8fNpPjt9W0wXp9WOaz1xFtJQaHSl4vXczpWMeUiOFuPqQtx2JxJ9dhNTLLRCS/g65baY4oBT NfyEdZx+UlkIKeTdgtrFTueIHS2Gg1as72l1LJCbRkDAMTf1/qw4ChLAiHUbg3fJXPGpHh1rAil aBY2Ebi4Vf3gwfQPWMBVD0BtdUUB+vhL9zE774HADG2jNk/nicVcZIRYT/YCRCVYjmws0XnQeh7 +atmkRY2Zt5o= X-Received: by 2002:a17:907:6d05:b0:c25:5a7:87f with SMTP id a640c23a62f3a-c25566499e8mr34430266b.0.1787852278645; Thu, 27 Aug 2026 10:37:58 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20260821-swap-thp-cleanup-v3-0-9b43f5163238@tencent.com> <20260821-swap-thp-cleanup-v3-9-9b43f5163238@tencent.com> In-Reply-To: From: Kairui Song Date: Fri, 28 Aug 2026 01:37:20 +0800 X-Gm-Features: AcwNN1XusF7KPTBCbFIorg-MpoUYcu7AsrCOyjMNN0VFuVbYt9OK7HHTzHSMN6Q Message-ID: Subject: Re: [PATCH v3 09/18] mm/huge_memory: move anon_vma and filemap management into split helpers To: "David Hildenbrand (Arm)" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Chris Li , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Shivam Kalra Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Aug 28, 2026 at 12:36=E2=80=AFAM David Hildenbrand (Arm) wrote: > > On 8/20/26 20:55, Kairui Song via B4 Relay wrote: > > From: Kairui Song > > > > Only anon split needs vma info, and only file split needs the filemap > > handling. Move the related code into separate helpers so they are > > genuinely more self-contained. > > This patch seems to do more than that, like relocating the > folio_expected_ref_count check (and duplicating it, which is not so nice)= . > > > > > Reviewed-by: Zi Yan > > Signed-off-by: Kairui Song > > --- > > [...] > > > - /* > > - * Racy check if we can split the page, before unmap_folio() will > > - * split PMDs > > - */ > > - if (folio_expected_ref_count(folio) !=3D folio_ref_count(folio) -= 1) { > > - ret =3D -EAGAIN; > > - goto out_unlock; > > - } > > - > > - if (!is_anon) { > > - ret =3D __folio_split_unmap_and_freeze_file(folio, new_or= der, split_at, &xas, mapping, > > - true, list, spl= it_type); > > - } else { > > + if (is_anon) > > ret =3D __folio_split_unmap_and_freeze_anon(folio, new_or= der, split_at, true, > > true, list, spl= it_type); > > - } > > Inverting the conditional seems to produce unnecessary noise in this patc= h. Will try to make this look nicer.