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 EFC2A3204 for ; Tue, 3 May 2022 15:14:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CAF7C385A4; Tue, 3 May 2022 15:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651590842; bh=Sj1vTOeAv+Oacr7lRscJDfSOWLqwBxyp2EyvsqLxJiY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oeuRzFyLU37V1RLJqvymZraTIQhhFq1GvoN08S12FqaVSrewH4Fgx67wpcepZU8/x i4TFI6DQlXjHVXiTFfhykA5Hrrt4cSgcL/zvbZBFcSSxFxQ6s3orwnm8PeyTX9e0kd 67+p12AVbgUDGJeLnR4+1dtafYLlfuEgzCSs5pf0oPA2N1pmH3o6kkEGlzB73h89WP KpKUPs/nWqS2sE3Or90yrVt7SLzhkhebQyqRV1WP0bGMGFqfq8tkhbSFkSTLrzLLbO lfoGRjkUkMQa3KKb3/6ZB77t3kVhKzjdaELlX07zz5ZS/Hzbycp2hcm9hH4+5kRMvo ufSAyTdXWIOtQ== Date: Tue, 3 May 2022 08:14:00 -0700 From: Nathan Chancellor To: "Matthew Wilcox (Oracle)" Cc: akpm@linuxfoundation.org, linux-mm@kvack.org, llvm@lists.linux.dev Subject: Re: [PATCH 00/21] Folio patches for 5.19 Message-ID: References: <20220429192329.3034378-1-willy@infradead.org> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220429192329.3034378-1-willy@infradead.org> On Fri, Apr 29, 2022 at 08:23:08PM +0100, Matthew Wilcox (Oracle) wrote: > Andrew, do you want to include these patches in -mm? > > - Finish the conversion from alloc_pages_vma() to vma_alloc_folio() > - Finish converting shrink_page_list() to folios > - Start converting shmem from pages to folios (alas, not finished, > I have simply run out of time with all the debugging/fixing needed > for 5.18) > > Matthew Wilcox (Oracle) (21): > shmem: Convert shmem_alloc_hugepage() to use vma_alloc_folio() > mm/huge_memory: Convert do_huge_pmd_anonymous_page() to use > vma_alloc_folio() > mm: Remove alloc_pages_vma() > vmscan: Use folio_mapped() in shrink_page_list() > vmscan: Convert the writeback handling in shrink_page_list() to folios > swap: Turn get_swap_page() into folio_alloc_swap() > swap: Convert add_to_swap() to take a folio > vmscan: Convert dirty page handling to folios > vmscan: Convert page buffer handling to use folios > vmscan: Convert lazy freeing to folios > vmscan: Move initialisation of mapping down > vmscan: Convert the activate_locked portion of shrink_page_list to > folios > vmscan: Remove remaining uses of page in shrink_page_list > mm/shmem: Use a folio in shmem_unused_huge_shrink > mm/swap: Add folio_throttle_swaprate > mm/shmem: Convert shmem_add_to_page_cache to take a folio > mm/shmem: Turn shmem_should_replace_page into > shmem_should_replace_folio > mm/shmem: Turn shmem_alloc_page() into shmem_alloc_folio() > mm/shmem: Convert shmem_alloc_and_acct_page to use a folio > mm/shmem: Convert shmem_getpage_gfp to use a folio > mm/shmem: Convert shmem_swapin_page() to shmem_swapin_folio() This series is now in next-20220503 and causes the following clang warnings: mm/shmem.c:1704:7: error: variable 'folio' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] if (!page) { ^~~~~ mm/shmem.c:1761:6: note: uninitialized use occurs here if (folio) { ^~~~~ mm/shmem.c:1704:3: note: remove the 'if' if its condition is always false if (!page) { ^~~~~~~~~~~~ mm/shmem.c:1685:21: note: initialize the variable 'folio' to silence this warning struct folio *folio; ^ = NULL mm/shmem.c:2340:8: error: variable 'page' is uninitialized when used here [-Werror,-Wuninitialized] if (!page) ^~~~ mm/shmem.c:2321:19: note: initialize the variable 'page' to silence this warning struct page *page; ^ = NULL 2 errors generated. The first warning is pretty simple as far as I can tell: diff --git a/mm/shmem.c b/mm/shmem.c index 820fde6c2ef6..6a18641a90ff 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1682,7 +1682,7 @@ static int shmem_swapin_folio(struct inode *inode, pgoff_t index, struct shmem_inode_info *info = SHMEM_I(inode); struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL; struct page *page; - struct folio *folio; + struct folio *folio = NULL; swp_entry_t swap; int error; However, I am not sure about the second one. It appears to be caused by patch 18 in this series. Should it have actually been: diff --git a/mm/shmem.c b/mm/shmem.c index 820fde6c2ef6..9e0bd0cffe30 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2337,6 +2337,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, if (!*pagep) { ret = -ENOMEM; + page = &shmem_alloc_folio(gfp, info, pgoff)->page; if (!page) goto out_unacct_blocks; ? Cheers, Nathan