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 65B4D17BBA; Thu, 22 Feb 2024 23:39:26 +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=1708645166; cv=none; b=mexrVnv1NLzkVzPzZk2QiAqHWVvI/qGNdNFhTavFSkfm95TRbplf7v3l7OYYT7CDP08i7dNzNDUC3S9A/seazcTaGZrFfwf4Lcop54AR7Yt5hk2TypSuhwj0Xylm5WZTthM8seH+SyYyz2jkbxuX5Z6mE5cMaSO0TGkccjXRGwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708645166; c=relaxed/simple; bh=7Zz9N2qREAhZwfH7evuuc/XT4gBx9hbfdzNuiYDkEA0=; h=Date:To:From:Subject:Message-Id; b=VmnYA+L9mmMof43SMoclhnafREeDhDPGGL3JT2EriS11Psz9I+ij7+EvZK3P3HgIwCdm7IfyAkYcVPA4Hzt+eV2VYK5hpdHV1MmI4yXn1ebowyTMM5i/ZJpiTL/CzA81kTRJ+j168G9ucJ6rXCfh8klkT4RWvDT5Z/enFjRHZOY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ItWMVVKO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ItWMVVKO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF575C433F1; Thu, 22 Feb 2024 23:39:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1708645166; bh=7Zz9N2qREAhZwfH7evuuc/XT4gBx9hbfdzNuiYDkEA0=; h=Date:To:From:Subject:From; b=ItWMVVKOVit+9SnGpHLCewpuKWf/LjA1H09pBoLorMKZfNqicV3+deELn3dILvpfq C/8eo431o3QPg1SNbZWX9rLq7CPFmL4N84hXzYpC6LRKwChL409HavMJkdZjV41MAC sSdyudk1fn4QD6CzbewzNhm20zZx8NRoVYmG4UIA= Date: Thu, 22 Feb 2024 15:39:25 -0800 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,riel@surriel.com,peterz@infradead.org,mingo@kernel.org,mgorman@techsingularity.net,willy@infradead.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] bounds-support-non-power-of-two-config_nr_cpus.patch removed from -mm tree Message-Id: <20240222233925.DF575C433F1@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: bounds: support non-power-of-two CONFIG_NR_CPUS has been removed from the -mm tree. Its filename was bounds-support-non-power-of-two-config_nr_cpus.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" Subject: bounds: support non-power-of-two CONFIG_NR_CPUS Date: Tue, 10 Oct 2023 15:55:49 +0100 ilog2() rounds down, so for example when PowerPC 85xx sets CONFIG_NR_CPUS to 24, we will only allocate 4 bits to store the number of CPUs instead of 5. Use bits_per() instead, which rounds up. Found by code inspection. The effect of this would probably be a misaccounting when doing NUMA balancing, so to a user, it would only be a performance penalty. The effects may be more wide-spread; it's hard to tell. Link: https://lkml.kernel.org/r/20231010145549.1244748-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Fixes: 90572890d202 ("mm: numa: Change page last {nid,pid} into {cpu,pid}") Reviewed-by: Rik van Riel Acked-by: Mel Gorman Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Signed-off-by: Andrew Morton --- kernel/bounds.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bounds.c~bounds-support-non-power-of-two-config_nr_cpus +++ a/kernel/bounds.c @@ -19,7 +19,7 @@ int main(void) DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS); DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES); #ifdef CONFIG_SMP - DEFINE(NR_CPUS_BITS, ilog2(CONFIG_NR_CPUS)); + DEFINE(NR_CPUS_BITS, bits_per(CONFIG_NR_CPUS)); #endif DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t)); #ifdef CONFIG_LRU_GEN _ Patches currently in -mm which might be from willy@infradead.org are writeback-remove-a-duplicate-prototype-for-tag_pages_for_writeback.patch writeback-factor-folio_prepare_writeback-out-of-write_cache_pages.patch writeback-factor-writeback_get_batch-out-of-write_cache_pages.patch writeback-simplify-the-loops-in-write_cache_pages.patch pagevec-add-ability-to-iterate-a-queue.patch writeback-use-the-folio_batch-queue-iterator.patch writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch writeback-remove-a-use-of-write_cache_pages-from-do_writepages.patch