From nobody Tue Apr 7 14:03:40 2026 Received: from mail-ed1-f74.google.com (mail-ed1-f74.google.com [209.85.208.74]) (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 49BB13E8C68 for ; Wed, 25 Feb 2026 15:40:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772034008; cv=none; b=XIxGTTUXZriLDs4P19fXjYraV8VkXKkHEq8BA9B8Ji1TK+nuhbnZs0cXYBbrbOLyxX1Nl9ZQzgghrd+XYBZNolEcwCX2BnJikgPdHXJmZuEUl24p5v92sluoa9tyHyfzlhhfXaWKy/B1fDHvwIbV1m1L0Sc2EgR/JxhZM2vHMGI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772034008; c=relaxed/simple; bh=9dnP3Kplei6Wvy5lZCCybShSS/eX737SSWZf8GOKF0s=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=tg1SUas6aDksn+WyN9TmOuYEslqm0NMTVGZc9PpYwc6RybwmQK1IDttYq0E80Dd23GXu3nCFmFAQUqaSB/bLXRG0Oe1gzf41YCcTuKznfF8VxyZ6DTlblF8cvxu3dRDDiY+NwA9rzOgAj4ryZhSSraAgidT1oOciQsF+4RIsP2E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--mclapinski.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Fb/bh5XX; arc=none smtp.client-ip=209.85.208.74 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--mclapinski.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Fb/bh5XX" Received: by mail-ed1-f74.google.com with SMTP id 4fb4d7f45d1cf-65b26363923so8688934a12.0 for ; Wed, 25 Feb 2026 07:40:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772034005; x=1772638805; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ipTaz++qTtdDCBjKXU7vNcSleKIn31kyDo4+ZfAiimU=; b=Fb/bh5XXeVIc39NxAkAA1PwmxflJCtbAl7mIdqJu7mJqD/XOIqhNk9Q+c/rqJz3ltk SouJJXJ2Aj2OUHBbIHUGQ1b/oCwVl6xDYtIABn8UXEHia0oVZZDsgJtYhR6DiMsfDmqV fJj9O9np6SVwEQjBaXZl/fBwC57tgwZqXmiKCFH2OXiMl0qZxdeddjN5wFz5L7OYficf ZVWUjL9bWK5qLcN02UD1V1zmGbIlEiOg4gm1bocgNvA2E6suVvDzOqrauQhqGq37L3BD k9WgXgrZEbcCEoMUIarWgNoUAPbS8ijHR92YrVRSUzUbWVcu4/+NW166ZGzj1uoQUSWe 6IOA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772034005; x=1772638805; 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=ipTaz++qTtdDCBjKXU7vNcSleKIn31kyDo4+ZfAiimU=; b=eleyAIXcFjulYlQQOKdhBcRpB+4xE8U+njjvbczohHcsihe326S+EitG0i9ItYleA6 os2WV2L5TOkAJ+p0YU9MOeh7W+lxahbwY1FK2UoJwHi6gm896xEiRqveB7IDqR/Xsg8S rlxKCvVvj6c/LJDnfKIwKL3Vb4RvavV1MLFniyFGqXggVi7R9vo2jUPZfLSp05QUaRvj X6oMVq6BH3gnRawZu3Eqg/3XBk+y7jDt8zNau5RJous8sBwag7B3cWDkOUesbagfYOlP TNEQOOANnZz4KMpE2nHnp1ynsLBz74+eeVfn14WnYKrIPnSYPoiuIGI0CLrGnUeuq7HW IFQg== X-Gm-Message-State: AOJu0Yx8pzs85lmAxeKza1Ee+JSQcbPo0ts/wIB82TMGuTwi+YWBUgWq Bar+3KSVh7hsquWdv0drfL2ZXtKjwInx7JkOQR9OLHJzbip0DNYdVJ+Crx8KB01INbgdLRaCD2K 6IzP0txCq8RdSrWTgJ1FSaA== X-Received: from edsu1.prod.google.com ([2002:aa7:d981:0:b0:65a:1eb4:60db]) (user=mclapinski job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:360e:b0:65f:7000:928f with SMTP id 4fb4d7f45d1cf-65f700095a8mr3689412a12.0.1772034005339; Wed, 25 Feb 2026 07:40:05 -0800 (PST) Date: Wed, 25 Feb 2026 16:39:54 +0100 In-Reply-To: <20260225153955.1006649-1-mclapinski@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260225153955.1006649-1-mclapinski@google.com> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog Message-ID: <20260225153955.1006649-2-mclapinski@google.com> Subject: [PATCH v5 1/2] kho: fix deferred init of kho scratch From: Michal Clapinski To: Evangelos Petrongonas , Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Alexander Graf , kexec@lists.infradead.org, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , Michal Clapinski Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Currently, mm_core_init calls kho_memory_init, which calls kho_release_scratch. If DEFERRED is enabled, kho_release_scratch will first initialize the struct pages of kho scratch. This is not needed. We can just let page_alloc_init_late init it. Next, kho_release_scratch will mark scratch as MIGRATE_CMA. If DEFERRED is enabled, this will be overwritten later in deferred_free_pages. To fix this, I removed the whole kho_release_scratch. Marking the pageblocks as MIGRATE_CMA now happens in kho_init, which runs after deferred_free_pages. Signed-off-by: Michal Clapinski Reviewed-by: Mike Rapoport (Microsoft) --- include/linux/memblock.h | 2 -- kernel/liveupdate/kexec_handover.c | 43 ++++++++---------------------- mm/memblock.c | 22 --------------- 3 files changed, 11 insertions(+), 56 deletions(-) diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 6ec5e9ac0699..3e217414e12d 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -614,11 +614,9 @@ static inline void memtest_report_meminfo(struct seq_f= ile *m) { } #ifdef CONFIG_MEMBLOCK_KHO_SCRATCH void memblock_set_kho_scratch_only(void); void memblock_clear_kho_scratch_only(void); -void memmap_init_kho_scratch_pages(void); #else static inline void memblock_set_kho_scratch_only(void) { } static inline void memblock_clear_kho_scratch_only(void) { } -static inline void memmap_init_kho_scratch_pages(void) {} #endif =20 #endif /* _LINUX_MEMBLOCK_H */ diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_h= andover.c index 410098bae0bf..1e1f69b10457 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -1388,11 +1388,6 @@ static __init int kho_init(void) if (err) goto err_free_fdt; =20 - if (fdt) { - kho_in_debugfs_init(&kho_in.dbg, fdt); - return 0; - } - for (int i =3D 0; i < kho_scratch_cnt; i++) { unsigned long base_pfn =3D PHYS_PFN(kho_scratch[i].addr); unsigned long count =3D kho_scratch[i].size >> PAGE_SHIFT; @@ -1408,8 +1403,17 @@ static __init int kho_init(void) */ kmemleak_ignore_phys(kho_scratch[i].addr); for (pfn =3D base_pfn; pfn < base_pfn + count; - pfn +=3D pageblock_nr_pages) - init_cma_reserved_pageblock(pfn_to_page(pfn)); + pfn +=3D pageblock_nr_pages) { + if (fdt) + init_cma_pageblock(pfn_to_page(pfn)); + else + init_cma_reserved_pageblock(pfn_to_page(pfn)); + } + } + + if (fdt) { + kho_in_debugfs_init(&kho_in.dbg, fdt); + return 0; } =20 WARN_ON_ONCE(kho_debugfs_fdt_add(&kho_out.dbg, "fdt", @@ -1435,35 +1439,10 @@ static __init int kho_init(void) } fs_initcall(kho_init); =20 -static void __init kho_release_scratch(void) -{ - phys_addr_t start, end; - u64 i; - - memmap_init_kho_scratch_pages(); - - /* - * Mark scratch mem as CMA before we return it. That way we - * ensure that no kernel allocations happen on it. That means - * we can reuse it as scratch memory again later. - */ - __for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, - MEMBLOCK_KHO_SCRATCH, &start, &end, NULL) { - ulong start_pfn =3D pageblock_start_pfn(PFN_DOWN(start)); - ulong end_pfn =3D pageblock_align(PFN_UP(end)); - ulong pfn; - - for (pfn =3D start_pfn; pfn < end_pfn; pfn +=3D pageblock_nr_pages) - init_pageblock_migratetype(pfn_to_page(pfn), - MIGRATE_CMA, false); - } -} - void __init kho_memory_init(void) { if (kho_in.scratch_phys) { kho_scratch =3D phys_to_virt(kho_in.scratch_phys); - kho_release_scratch(); =20 if (kho_mem_retrieve(kho_get_fdt())) kho_in.fdt_phys =3D 0; diff --git a/mm/memblock.c b/mm/memblock.c index b3ddfdec7a80..ae6a5af46bd7 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -959,28 +959,6 @@ __init void memblock_clear_kho_scratch_only(void) { kho_scratch_only =3D false; } - -__init void memmap_init_kho_scratch_pages(void) -{ - phys_addr_t start, end; - unsigned long pfn; - int nid; - u64 i; - - if (!IS_ENABLED(CONFIG_DEFERRED_STRUCT_PAGE_INIT)) - return; - - /* - * Initialize struct pages for free scratch memory. - * The struct pages for reserved scratch memory will be set up in - * reserve_bootmem_region() - */ - __for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, - MEMBLOCK_KHO_SCRATCH, &start, &end, &nid) { - for (pfn =3D PFN_UP(start); pfn < PFN_DOWN(end); pfn++) - init_deferred_page(pfn, nid); - } -} #endif =20 /** --=20 2.53.0.414.gf7e9f6c205-goog