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 B4AF23B4E9F; Wed, 1 Jul 2026 07:54:20 +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=1782892461; cv=none; b=to3n6IE41qF/kC3izxfirIkmKHO+DR6AFii/wQaGjI0z2Wa24ykvti3p6y8y1V8VP7JtZc5dm4BufXljOkOD34iHy9EWXTTg5QKZS+LEJJ5biMXzr38gBHDl6dPjySjpOJH6ws3GieqC1YD3RSR4FndfZbEHuEP0MehK5NJBNX0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782892461; c=relaxed/simple; bh=mPD+qRXEfU1wO98S4uDFWeKRFfdhDgOSb9qj5Jo4DYk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Z5vuJMr17TbhrtxAvMAOW4kIRSpaVXU+DFVQ1u6gHRyUvTNxEXoTmEouTmdJguUVcxYEGwaGipHFulW+esEumcRMkNqmNYW2gGiKS3ire4tFn2myjpwSD7HJvKWxjuo94oHSQY2ZToil+19YzxMY+Xa5JM0vFzu+7Qsaq40QY6s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FPMJNrxy; 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="FPMJNrxy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 529261F00A3A; Wed, 1 Jul 2026 07:54:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782892460; bh=OoGwCpoz9l+DaS9yK/T7aMyhiRavJfkssRFkVojsyeU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=FPMJNrxyKsiNwu1e5dvMIa8aiWktThZ4oTvZuWEl/UwLIdXaJMCXh6FKTK4L0516+ sbZagLjisYsO7E5gKG00+R/P5l7U1dAeqLHGieYJo6h0ygrlxD43xFZo3OU3naopx9 Pa61i0hCt1hTvGYqaKVTClH3x9JwNkdC8DWLcNkgjl5V8QU9Dq2gqYPB0pIJhivGWi aqYyw7u1bLhXIbuehVx3el4lmfgeKc7QpxyvtVK2PCBE7YCwomLsKsxcpJMAmhWCLT 2/FGiWnuHPfGyCgHSAh+xg1cAB6d01llOP8lcrDlLKvR73Us9Oo8mEWjIsTbyLi3SF Uul1PhhqAWz5A== Message-ID: Date: Wed, 1 Jul 2026 09:54:13 +0200 Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 13/16] mm: Remove __alloc_pages_node() Content-Language: en-US To: Brendan Jackman , Andrew Morton , Suren Baghdasaryan , Michal Hocko , Johannes Weiner , Zi Yan , Muchun Song , Oscar Salvador , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt Cc: "Harry Yoo (Oracle)" , Gregory Price , Alexei Starovoitov , Matthew Wilcox , Hao Ge , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev References: <20260629-alloc-trylock-v3-0-57bef0eadbc2@google.com> <20260629-alloc-trylock-v3-13-57bef0eadbc2@google.com> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <20260629-alloc-trylock-v3-13-57bef0eadbc2@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/29/26 15:12, Brendan Jackman wrote: > There were only a few users, which have been removed. The only advantage > of this API over alloc_pages_node() is avoiding a single conditional > branch. The disadvantages are: > > 1. More API surface, more sources of confusion, more maintenance. > > 2. Worse impact of CPU hotplug bugs: most users of __alloc_pages_node() > were using the result of cpu_to_node(); if the CPU gets hotplugged > out this will return NUMA_NO_NODE. If one of these paths fails to > protect against a concurrent hotplug then page_alloc.c will use > NUMA_NO_NODE as an index into NODE_DATA() and cause some horrible > memory corruption or other. With alloc_pages_node(), the code might > just work fine. > > Ulterior motive: this frees up the __* variants of the allocator APIs to > serve specifically for use as mm-internal API. > > Reviewed-by: Suren Baghdasaryan > Signed-off-by: Brendan Jackman Reviewed-by: Vlastimil Babka (SUSE) > --- > include/linux/gfp.h | 20 ++++---------------- > 1 file changed, 4 insertions(+), 16 deletions(-) > > diff --git a/include/linux/gfp.h b/include/linux/gfp.h > index 01d6d2591f49e..3bf55a5f9143e 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -256,21 +256,6 @@ static inline void warn_if_node_offline(int this_node, gfp_t gfp_mask) > dump_stack(); > } > > -/* > - * Allocate pages, preferring the node given as nid. The node must be valid and > - * online. For more general interface, see alloc_pages_node(). > - */ > -static inline struct page * > -__alloc_pages_node_noprof(int nid, gfp_t gfp_mask, unsigned int order) > -{ > - VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES); > - warn_if_node_offline(nid, gfp_mask); > - > - return __alloc_pages_noprof(gfp_mask, order, nid, NULL); > -} > - > -#define __alloc_pages_node(...) alloc_hooks(__alloc_pages_node_noprof(__VA_ARGS__)) > - > static inline > struct folio *__folio_alloc_node_noprof(gfp_t gfp, unsigned int order, int nid) > { > @@ -293,7 +278,10 @@ static inline struct page *alloc_pages_node_noprof(int nid, gfp_t gfp_mask, > if (nid == NUMA_NO_NODE) > nid = numa_mem_id(); > > - return __alloc_pages_node_noprof(nid, gfp_mask, order); > + VM_BUG_ON(nid < 0 || nid >= MAX_NUMNODES); > + warn_if_node_offline(nid, gfp_mask); > + > + return __alloc_pages_noprof(gfp_mask, order, nid, NULL); > } > > #define alloc_pages_node(...) alloc_hooks(alloc_pages_node_noprof(__VA_ARGS__)) >