From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f73.google.com (mail-ej1-f73.google.com [209.85.218.73]) (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 BD9DF3A254A for ; Mon, 22 Jun 2026 10:01:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782122508; cv=none; b=lrkzMKscG7PE6VkUqvymm5BFARI6A4K8sNGD9nTYye0ZwreJevpE1lc/aDTV3D8ciH5xnoMnKnzjnfD1ZBNNJsT9HzjOc+nUNn3+KQBxZWFpgjcrHnPzDrjCF4pqDoW+Ye7/pO8KlJHIagx03Mj9LKmF72+jFYWFn9hktZCWr/Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782122508; c=relaxed/simple; bh=kv7GTwDm/5n35EceFdwQWo0vB+5W6ET2TxIaDEmzekc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=I1a8C4zpl10X9Rkh0iTViD6v7zH1HbVOgwOrNV5l3tJus78cQSo0WgGAOhbjLwaO6TXLqBqC4NXREdQ2xN1TF6BY9zDFE5naOa+QjXqmyPvI81JACiHj/irK6Dj8NgzzLPDpqkOEvdF6LP7M4IgnQbe4BJYNlVObBWOXcotUn5Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=aEovy7Xk; arc=none smtp.client-ip=209.85.218.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--jackmanb.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="aEovy7Xk" Received: by mail-ej1-f73.google.com with SMTP id a640c23a62f3a-c0774fb9eddso305106966b.1 for ; Mon, 22 Jun 2026 03:01:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782122504; x=1782727304; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=u1/cP6vHwWuZGO/mgc7SKKRNMY8A0RgkRxhrS8s00BQ=; b=aEovy7XkxO7UyJ2cS9MzUKgisSAg8NV3TiHymla6bu/4AUW/LaJU7c5x7bbYFSVDXT WiRmWllg8Pi9vsfAES7tUr9cenLtGBiDcMEOGqGjXmHQE3oZ0dBvSUYpq5d8GFbWXDOu i9/BeBJwpOafTDIw+hILNmFGCI8crRE8F+nPgwyx9FNXTXN1PSM3su/mIuPuoW8JeiLL rej1F0PLw4BslTbLanoJi9Fkw2ijGj/5I9mhDFoXejFnMXDcyTvtfWTvn29j7tPJak6O yeoLW7M6KBd51MdLE6vI9tU2JBg22xVIX8O96z3z2Q1Z5j8bczoBO5PZBYM8JSCaa8Fr f+Mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782122504; x=1782727304; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=u1/cP6vHwWuZGO/mgc7SKKRNMY8A0RgkRxhrS8s00BQ=; b=HgL2qQq6PQL4IGobmxz5Wrwy1lHTDILO/72TxIhI32tYzsJQF2vOv0BH5pFAovddUH SUvtxCATj5FgWtaJGnnDoAeb52qMn6z0nBYNf0Tnd/+/LA0LT7v0VBTYDgekszzYFZ4P 8WBj2GQu6EUFzudroaWJXWUx4DjrWiFEPUNkMqlRNk4FzB5Nec6Rk7nJHpvk6hMW7qsP HqXcG4oA2aIrmb22DQHUcvEVuhX/to39UkvOMX1a6gCgyJLUp6dVp6Vp0hmQuYgUqQdx WQBpC1ECGorcCBgIsHvS/q4WUZXOmid0NAvoJ2Fw3Xc4UsX7LcLyCoBz02lY+6ibgHy/ uANg== X-Forwarded-Encrypted: i=1; AFNElJ+GaGSDc1Y4wAiFfLBaELXWeJu82rNL+CI9sFcx1gH/FLLRM+jP2eyTWWzC6RwmSEYrs9+7gxJLuw7D3wKvJw==@lists.linux.dev X-Gm-Message-State: AOJu0YwZ6hMmeGCHtTKnMabbGk8/U2JU6Nc9PSyhI1MjJjQ5j6t4Zlg4 hnHXA2yQtvLyATLR5hNCv0PQINllbHjDfYnCOqxYv7bKhOuLAyzt6Skj88EU7cRXp7iTWZwh5uI qbBmOaVAQ+WsSjw== X-Received: from ejbyz10.prod.google.com ([2002:a17:906:dc4a:b0:c07:7108:ccd2]) (user=jackmanb job=prod-delivery.src-stubby-dispatcher) by 2002:a17:907:c01c:b0:bee:bbaa:f19d with SMTP id a640c23a62f3a-c0b61132b41mr553875566b.14.1782122503188; Mon, 22 Jun 2026 03:01:43 -0700 (PDT) Date: Mon, 22 Jun 2026 10:01:29 +0000 In-Reply-To: <20260622-alloc-trylock-v2-0-31f31367d420@google.com> Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260622-alloc-trylock-v2-0-31f31367d420@google.com> X-Mailer: b4 0.15.2 Message-ID: <20260622-alloc-trylock-v2-2-31f31367d420@google.com> Subject: [PATCH v2 02/13] mm/page_alloc: some renames to clarify alloc_flags scopes From: Brendan Jackman To: Andrew Morton , Vlastimil Babka , 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 , Johannes Weiner , Alexei Starovoitov , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Brendan Jackman Content-Type: text/plain; charset="utf-8" It's pretty confusing that: - The slowpath and fastpath have a totally distinct set of alloc_flags. - gfp_to_alloc_flags() sounds generic but it only influences the slowpath. - prepare_alloc_pages() is generic in that it sets up the alloc_context, but the alloc_flags it generates are only used for the fastpath. Rename some variables to highlight which alloc_flags are fastpath-specific. Rename gfp_to_alloc_flags() to highlight that it's slowpath-specific. gfp_to_alloc_flags_cma()'s current name is actually fine, but rename it anyway, just for consistency. Signed-off-by: Brendan Jackman --- mm/page_alloc.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6c4eb6908bd95..bc05d75a41627 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3771,8 +3771,8 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) } /* Must be called after current_gfp_context() which can change gfp_mask */ -static inline unsigned int gfp_to_alloc_flags_cma(gfp_t gfp_mask, - unsigned int alloc_flags) +static inline unsigned int cma_alloc_flags(gfp_t gfp_mask, + unsigned int alloc_flags) { #ifdef CONFIG_CMA if (gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) @@ -4471,7 +4471,7 @@ static void wake_all_kswapds(unsigned int order, gfp_t gfp_mask, } static inline unsigned int -gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order) +slowpath_alloc_flags(gfp_t gfp_mask, unsigned int order) { unsigned int alloc_flags = ALLOC_WMARK_MIN | ALLOC_CPUSET; @@ -4508,7 +4508,7 @@ gfp_to_alloc_flags(gfp_t gfp_mask, unsigned int order) } else if (unlikely(rt_or_dl_task(current)) && in_task()) alloc_flags |= ALLOC_MIN_RESERVE; - alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags); + alloc_flags = cma_alloc_flags(gfp_mask, alloc_flags); if (defrag_mode) alloc_flags |= ALLOC_NOFRAGMENT; @@ -4774,7 +4774,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, * kswapd needs to be woken up, and to avoid the cost of setting up * alloc_flags precisely. So we do that now. */ - alloc_flags = gfp_to_alloc_flags(gfp_mask, order); + alloc_flags = slowpath_alloc_flags(gfp_mask, order); /* * We need to recalculate the starting point for the zonelist iterator @@ -4815,7 +4815,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); if (reserve_flags) - alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags) | + alloc_flags = cma_alloc_flags(gfp_mask, reserve_flags) | (alloc_flags & ALLOC_KSWAPD); /* @@ -5017,7 +5017,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, int preferred_nid, nodemask_t *nodemask, struct alloc_context *ac, gfp_t *alloc_gfp, - unsigned int *alloc_flags) + unsigned int *fastpath_alloc_flags) { ac->highest_zoneidx = gfp_zone(gfp_mask); ac->zonelist = node_zonelist(preferred_nid, gfp_mask); @@ -5033,7 +5033,7 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, if (in_task() && !ac->nodemask) ac->nodemask = &cpuset_current_mems_allowed; else - *alloc_flags |= ALLOC_CPUSET; + *fastpath_alloc_flags |= ALLOC_CPUSET; } might_alloc(gfp_mask); @@ -5042,11 +5042,11 @@ static inline bool prepare_alloc_pages(gfp_t gfp_mask, unsigned int order, * Don't invoke should_fail logic, since it may call * get_random_u32() and printk() which need to spin_lock. */ - if (!(*alloc_flags & ALLOC_NOLOCK) && + if (!(*fastpath_alloc_flags & ALLOC_NOLOCK) && should_fail_alloc_page(gfp_mask, order)) return false; - *alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, *alloc_flags); + *fastpath_alloc_flags = cma_alloc_flags(gfp_mask, *fastpath_alloc_flags); /* Dirty zone balancing only done in the fast path */ ac->spread_dirty_pages = (gfp_mask & __GFP_WRITE); @@ -5260,7 +5260,7 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order, int preferred_nid, nodemask_t *nodemask) { struct page *page; - unsigned int alloc_flags = ALLOC_WMARK_LOW; + unsigned int fastpath_alloc_flags = ALLOC_WMARK_LOW; gfp_t alloc_gfp; /* The gfp_t that was actually used for allocation */ struct alloc_context ac = { }; @@ -5282,17 +5282,17 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order, gfp = current_gfp_context(gfp); alloc_gfp = gfp; if (!prepare_alloc_pages(gfp, order, preferred_nid, nodemask, &ac, - &alloc_gfp, &alloc_flags)) + &alloc_gfp, &fastpath_alloc_flags)) return NULL; /* * Forbid the first pass from falling back to types that fragment * memory until all local zones are considered. */ - alloc_flags |= alloc_flags_nofragment(zonelist_zone(ac.preferred_zoneref), gfp); + fastpath_alloc_flags |= alloc_flags_nofragment(zonelist_zone(ac.preferred_zoneref), gfp); /* First allocation attempt */ - page = get_page_from_freelist(alloc_gfp, order, alloc_flags, &ac); + page = get_page_from_freelist(alloc_gfp, order, fastpath_alloc_flags, &ac); if (likely(page)) goto out; -- 2.54.0