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 EB1C52C682 for ; Thu, 14 Dec 2023 22:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ohGVsv2G" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2797EC433C8; Thu, 14 Dec 2023 22:23:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1702592623; bh=qoi++B/TUWpnt2s6cs0eC4yVK4yKyIHerUy36lFyG8s=; h=Date:To:From:Subject:From; b=ohGVsv2G7nPqL0RoXtWRPyqrNECKgPTN8UvLSIWZWNaxV7ooNo8OKNdWFIdSwbyvC xhKiCaeQ0JRGkRaL/tb90PUM8r47AZsfkGnLB+zqWj/uMFaeRnm/+GRFzzqToeR17I jAeInTkaTBTPMk/PD/yUCgZkVYSdwp5/YSsVK/WE= Date: Thu, 14 Dec 2023 14:23:42 -0800 To: mm-commits@vger.kernel.org,zhouchengming@bytedance.com,yosryahmed@google.com,vitaly.wool@konsulko.com,sjenning@redhat.com,nphamcs@gmail.com,hannes@cmpxchg.org,ddstreet@ieee.org,chriscli@google.com,akpm@linux-foundation.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-zswap-cleanup-zswap_reclaim_entry-fix.patch added to mm-unstable branch Message-Id: <20231214222343.2797EC433C8@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm-zswap-cleanup-zswap_reclaim_entry-fix has been added to the -mm mm-unstable branch. Its filename is mm-zswap-cleanup-zswap_reclaim_entry-fix.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-cleanup-zswap_reclaim_entry-fix.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Andrew Morton Subject: mm-zswap-cleanup-zswap_reclaim_entry-fix Date: Thu Dec 14 02:21:39 PM PST 2023 retain comment, per Yosry Cc: Chengming Zhou Cc: Chris Li Cc: Dan Streetman Cc: Johannes Weiner Cc: Nhat Pham Cc: Seth Jennings Cc: Vitaly Wool Cc: Yosry Ahmed Signed-off-by: Andrew Morton --- mm/zswap.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/mm/zswap.c~mm-zswap-cleanup-zswap_reclaim_entry-fix +++ a/mm/zswap.c @@ -1457,8 +1457,14 @@ static int zswap_writeback_entry(struct mpol = get_task_policy(current); page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol, NO_INTERLEAVE_INDEX, &page_was_allocated, true); - if (!page) + if (!page) { + /* + * If we get here because the page is already in swapcache, a + * load may be happening concurrently. It is safe and okay to + * not free the entry. It is also okay to return !0. + */ return -ENOMEM; + } /* Found an existing page, we raced with load/swapin */ if (!page_was_allocated) { _ Patches currently in -mm which might be from akpm@linux-foundation.org are lib-maple_treec-fix-build-error-due-to-hotfix-alteration.patch mm-list_lruc-remove-unused-list_lru_from_kmem.patch mm-memcg-restore-subtree-stats-flushing-fix.patch mm-zswap-cleanup-zswap_reclaim_entry-fix.patch mips-fix-r3k_cache_init-build-regression-fix.patch