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 29F7D4692 for ; Mon, 11 Dec 2023 00:55:11 +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="iVjaP15x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9EF3C433C7; Mon, 11 Dec 2023 00:55:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1702256111; bh=FRD4jaWJiSd65svfzpx+fKz3elQ6x66AYjJUGV9bINg=; h=Date:To:From:Subject:From; b=iVjaP15xsqjD1plFp2J3f9lqRQuqDCu6VnsxIqAbHJEbVTzvP7NPPKRfLsmsqomvQ HaORmzxKAjvOBBSNAjqRmqW8Zi/xXB4Zpc44PDYTxKmo1/5d9VeElYvGDATf2JsFhH Sn9hEwadZBfijFYYD7964fMKN9zepqOHWZxfvx+Y= Date: Sun, 10 Dec 2023 16:55:10 -0800 To: mm-commits@vger.kernel.org,ira.weiny@intel.com,fabio.maria.de.francesco@linux.intel.com,fabio.maria.de.francesco@intel.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-ksm-use-kmap_local_page-in-calc_checksum.patch removed from -mm tree Message-Id: <20231211005510.E9EF3C433C7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/ksm: use kmap_local_page() in calc_checksum() has been removed from the -mm tree. Its filename was mm-ksm-use-kmap_local_page-in-calc_checksum.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Fabio M. De Francesco" Subject: mm/ksm: use kmap_local_page() in calc_checksum() Date: Mon, 20 Nov 2023 15:18:44 +0100 kmap_atomic() has been deprecated in favor of kmap_local_page(). Therefore, replace kmap_atomic() with kmap_local_page() in calc_checksum(). kmap_atomic() is implemented like a kmap_local_page() which also disables page-faults and preemption (the latter only in !PREEMPT_RT kernels). The kernel virtual addresses returned by these two API are only valid in the context of the callers (i.e., they cannot be handed to other threads). With kmap_local_page() the mappings are per thread and CPU local like in kmap_atomic(); however, they can handle page-faults and can be called from any context (including interrupts). The tasks that call kmap_local_page() can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. In calc_checksum(), the block of code between the mapping and un-mapping does not depend on the above-mentioned side effects of kmap_aatomic(), so that a mere replacements of the old API with the new one is all that is required (i.e., there is no need to explicitly call pagefault_disable() and/or preempt_disable()). Link: https://lkml.kernel.org/r/20231120141855.6761-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Cc: Ira Weiny Signed-off-by: Andrew Morton --- mm/ksm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/ksm.c~mm-ksm-use-kmap_local_page-in-calc_checksum +++ a/mm/ksm.c @@ -1099,9 +1099,9 @@ error: static u32 calc_checksum(struct page *page) { u32 checksum; - void *addr = kmap_atomic(page); + void *addr = kmap_local_page(page); checksum = xxhash(addr, PAGE_SIZE, 0); - kunmap_atomic(addr); + kunmap_local(addr); return checksum; } _ Patches currently in -mm which might be from fabio.maria.de.francesco@intel.com are