From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AB156423A76 for ; Tue, 20 Jan 2026 13:03:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768914234; cv=none; b=ZptK4dSLWSecCAyKcgvPHapt3MOsrd4rj4QIeutdvm36rS2TPvVT1OrkXIXghE02w+cc1jsQUDC1u5dMGLwguI2Cj9HZy/lJCZYpCXloXhtU2ffefohqbSl4TkAUVHS/PzcVaWqRep3t5iQVU+j8wI0kVG4wpINVumZhRAqjzPY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768914234; c=relaxed/simple; bh=VjNsk+rGW49szc0ZaDC/PxUEhkP0A5D50M/kBU1Njlc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=daD4qYf3VooBM3ku4Bmm2lAn/QRwEON2rSo5kVV5YT9Us1BxUfUeOqbmHICqHnO/u193NKTmoLmDDq2E22huZ6QLUb5ZpYiGXZGDy1HWni1POZqs2ezmwwRn+aSCWQmqClmGrjrC1ZZ7Qfm1hoZhludjWEBoN3KnbLw5uzyMiRo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IjSYQTxZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IjSYQTxZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8C6FC16AAE; Tue, 20 Jan 2026 13:03:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768914234; bh=VjNsk+rGW49szc0ZaDC/PxUEhkP0A5D50M/kBU1Njlc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IjSYQTxZO9zOdD8dgFokigXt6el1iimLLAw18aUnWCJHji5YWJKX+76HBlEkC0+nm shaw36qPYg7q8aymOeUc3lZgVkWU+ZuL3raurQsht2qGETyMlHKnqwl1f/1l2xOSE7 iiEEMdG7DRfOK6PIa5SEklmz+dMki95fKZ3WxKkzgQ9ShoxwBZ4bDZveME7VZL4SoY OgiNyNxxlSRXkBaBmCB5/xXtUVHl/OrU5jFCwY1TWAblP/9hShU2Xm5skNyRpr0Aa9 6aK5NAYPw03LVj7OBXyWXzxMYZ1YG7auxZS7kGxuTX3RoBC9pZ7UpoE/YXaPqlD1pQ aEr2k0DRRsGLg== Date: Tue, 20 Jan 2026 15:03:48 +0200 From: Mike Rapoport To: Pratyush Yadav Cc: Andrew Morton , Alexander Graf , Pasha Tatashin , kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Suren Baghdasaryan Subject: Re: [PATCH v2 1/2] kho: use unsigned long for nr_pages Message-ID: References: <20260116112217.915803-1-pratyush@kernel.org> <20260116112217.915803-2-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260116112217.915803-2-pratyush@kernel.org> On Fri, Jan 16, 2026 at 11:22:14AM +0000, Pratyush Yadav wrote: > With 4k pages, a 32-bit nr_pages can span up to 16 TiB. While it is a > lot, there exist systems with terabytes of RAM. gup is also moving to > using long for nr_pages. Use unsigned long and make KHO future-proof. > > Suggested-by: Pasha Tatashin > Signed-off-by: Pratyush Yadav Reviewed-by: Mike Rapoport (Microsoft) > --- > > Changes in v2: > - New in v2. > > include/linux/kexec_handover.h | 6 +++--- > kernel/liveupdate/kexec_handover.c | 11 ++++++----- > 2 files changed, 9 insertions(+), 8 deletions(-) > > diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h > index 5f7b9de97e8d..81814aa92370 100644 > --- a/include/linux/kexec_handover.h > +++ b/include/linux/kexec_handover.h > @@ -45,15 +45,15 @@ bool is_kho_boot(void); > > int kho_preserve_folio(struct folio *folio); > void kho_unpreserve_folio(struct folio *folio); > -int kho_preserve_pages(struct page *page, unsigned int nr_pages); > -void kho_unpreserve_pages(struct page *page, unsigned int nr_pages); > +int kho_preserve_pages(struct page *page, unsigned long nr_pages); > +void kho_unpreserve_pages(struct page *page, unsigned long nr_pages); > int kho_preserve_vmalloc(void *ptr, struct kho_vmalloc *preservation); > void kho_unpreserve_vmalloc(struct kho_vmalloc *preservation); > void *kho_alloc_preserve(size_t size); > void kho_unpreserve_free(void *mem); > void kho_restore_free(void *mem); > struct folio *kho_restore_folio(phys_addr_t phys); > -struct page *kho_restore_pages(phys_addr_t phys, unsigned int nr_pages); > +struct page *kho_restore_pages(phys_addr_t phys, unsigned long nr_pages); > void *kho_restore_vmalloc(const struct kho_vmalloc *preservation); > int kho_add_subtree(const char *name, void *fdt); > void kho_remove_subtree(void *fdt); > diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c > index 9dc51fab604f..709484fbf9fd 100644 > --- a/kernel/liveupdate/kexec_handover.c > +++ b/kernel/liveupdate/kexec_handover.c > @@ -222,7 +222,8 @@ static int __kho_preserve_order(struct kho_mem_track *track, unsigned long pfn, > static struct page *kho_restore_page(phys_addr_t phys, bool is_folio) > { > struct page *page = pfn_to_online_page(PHYS_PFN(phys)); > - unsigned int nr_pages, ref_cnt; > + unsigned long nr_pages; > + unsigned int ref_cnt; > union kho_page_info info; > > if (!page) > @@ -249,7 +250,7 @@ static struct page *kho_restore_page(phys_addr_t phys, bool is_folio) > * count of 1 > */ > ref_cnt = is_folio ? 0 : 1; > - for (unsigned int i = 1; i < nr_pages; i++) > + for (unsigned long i = 1; i < nr_pages; i++) > set_page_count(page + i, ref_cnt); > > if (is_folio && info.order) > @@ -283,7 +284,7 @@ EXPORT_SYMBOL_GPL(kho_restore_folio); > * > * Return: 0 on success, error code on failure > */ > -struct page *kho_restore_pages(phys_addr_t phys, unsigned int nr_pages) > +struct page *kho_restore_pages(phys_addr_t phys, unsigned long nr_pages) > { > const unsigned long start_pfn = PHYS_PFN(phys); > const unsigned long end_pfn = start_pfn + nr_pages; > @@ -829,7 +830,7 @@ EXPORT_SYMBOL_GPL(kho_unpreserve_folio); > * > * Return: 0 on success, error code on failure > */ > -int kho_preserve_pages(struct page *page, unsigned int nr_pages) > +int kho_preserve_pages(struct page *page, unsigned long nr_pages) > { > struct kho_mem_track *track = &kho_out.track; > const unsigned long start_pfn = page_to_pfn(page); > @@ -873,7 +874,7 @@ EXPORT_SYMBOL_GPL(kho_preserve_pages); > * kho_preserve_pages() call. Unpreserving arbitrary sub-ranges of larger > * preserved blocks is not supported. > */ > -void kho_unpreserve_pages(struct page *page, unsigned int nr_pages) > +void kho_unpreserve_pages(struct page *page, unsigned long nr_pages) > { > struct kho_mem_track *track = &kho_out.track; > const unsigned long start_pfn = page_to_pfn(page); > -- > 2.52.0.457.g6b5491de43-goog > -- Sincerely yours, Mike.