From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ADD302E7F25 for ; Tue, 26 May 2026 11:34:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779795293; cv=none; b=aZMhlhkZzV8FKfRNlf0E4n1w4n13W8f14+zkHxP7BF/Xw4ZHNO3f3AH87aycezweoQWjnlRRaXoGgGpt2OPgj/69l0eID/nNAEN00HI3zP/s/7UjBL18D4Ya4Y0ns3LW9MgV60WLCzvsK5wCeVmEqEjO6qH2/6K0DXrJtHjcwDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779795293; c=relaxed/simple; bh=dSas+2sdmRSh4smh7JG0UpTQkzxeSHa3nIcPtP/Wrts=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=j7/NBDqHQ8dpjBn18CyW1ln/zLjGsm+ePUh2v7jTLmB99CwqzLW2AYNsDwv5S1qXc2J0sMo1Ucgxq0R/q+nSchR/YBk1EJ6fN1ik29MU2JIUqQDSQBJB9hSzqro2uYdHoYx2e19eu2SjFVEXkAq72kzUu+gOSDMxPlUl7B0vFhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AuC8Ormn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AuC8Ormn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAFB71F00A3E; Tue, 26 May 2026 11:34:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779795292; bh=CYlCxqGn9eyAHsyJU/x1r418fe4eHyS6ad58vkdZw5c=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=AuC8OrmnkCS5GBts4i+afa7uSm8tobKvKBFSaLJnZqsdc6fnoquQIyLqzSyDqD9mL z9oQ5une4pGQforxy2zsV6Jl2QbjlCkmAmejphngaHc8VPBu+D/j/JhG6mRgR0fJ2U cTeAJzaBKhWMY7R+TmFkvjdix3Yf/h/1WKgl+FpwKgRbn4Wng7ZmdXetuvIGFr9ZPP odA/d4n9RB9HMVlQtPL7xXeRlcJv7W/onG//mAvvpTs7DZ6uILnQrCLVFV2fdEi8k2 Yfe4vAAFAnMGIydKy7orC/h8UcWKCgWyQ/Z49nmv7yAG6tovEzWBzzpCPkgmypITG2 DGeNrEbQtRhPA== Message-ID: Date: Tue, 26 May 2026 13:34:48 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/page_alloc: remove VM_BUG_ON()s from pindex helpers To: Brendan Jackman , Andrew Morton , Suren Baghdasaryan , Michal Hocko , Johannes Weiner , Zi Yan Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260526-page_alloc-unmapped-prep-v2-1-412f4d486115@google.com> From: "Vlastimil Babka (SUSE)" Content-Language: en-US In-Reply-To: <20260526-page_alloc-unmapped-prep-v2-1-412f4d486115@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/26/26 1:28 PM, Brendan Jackman wrote: > Vlastimil pointed out that the VM_BUG_ON()s have fallen out of > favour, so remove them. > > Suggested-by: Vlastimil Babka (SUSE) > Link: https://lore.kernel.org/all/4074a816-9e75-45a6-8141-25459bcc106b@kernel.org/ > Signed-off-by: Brendan Jackman Reviewed-by: Vlastimil Babka (SUSE) Thanks. > --- > Changes in v2: > - Rebased onto mm-new, removed VM_BUG_ON()s > - Link to v1: https://lore.kernel.org/r/20260513-page_alloc-unmapped-prep-v1-0-dacdf5402be8@google.com > --- > mm/page_alloc.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 1b5b1e556f76feadf21f3f44a9440fe883fb7651..e47679e7a9dbc772aa27f550a10aa8c0e95af55a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -653,13 +653,8 @@ static inline unsigned int order_to_pindex(int migratetype, int order) > if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { > bool movable = migratetype == MIGRATE_MOVABLE; > > - if (order > PAGE_ALLOC_COSTLY_ORDER) { > - VM_BUG_ON(!is_pmd_order(order)); > - > + if (order > PAGE_ALLOC_COSTLY_ORDER) > return NR_LOWORDER_PCP_LISTS + movable; > - } > - } else { > - VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); > } > > return (MIGRATE_PCPTYPES * order) + migratetype; > @@ -672,8 +667,6 @@ static inline int pindex_to_order(unsigned int pindex) > if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { > if (pindex >= NR_LOWORDER_PCP_LISTS) > order = HPAGE_PMD_ORDER; > - } else { > - VM_BUG_ON(order > PAGE_ALLOC_COSTLY_ORDER); > } > > return order; > > --- > base-commit: da0a06486ac3ce47c6ffb603d2fd332229d41592 > change-id: 20260512-page_alloc-unmapped-prep-c3ae0381d58b > > Best regards,