]> git.ipfire.org Git - thirdparty/kernel/stable-queue.git/commitdiff
4.19-stable patches
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Mar 2024 15:57:21 +0000 (16:57 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 29 Mar 2024 15:57:21 +0000 (16:57 +0100)
added patches:
bounds-support-non-power-of-two-config_nr_cpus.patch

queue-4.19/bounds-support-non-power-of-two-config_nr_cpus.patch [new file with mode: 0644]
queue-4.19/series

diff --git a/queue-4.19/bounds-support-non-power-of-two-config_nr_cpus.patch b/queue-4.19/bounds-support-non-power-of-two-config_nr_cpus.patch
new file mode 100644 (file)
index 0000000..b14d762
--- /dev/null
@@ -0,0 +1,41 @@
+From f2d5dcb48f7ba9e3ff249d58fc1fa963d374e66a Mon Sep 17 00:00:00 2001
+From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
+Date: Tue, 10 Oct 2023 15:55:49 +0100
+Subject: bounds: support non-power-of-two CONFIG_NR_CPUS
+
+From: Matthew Wilcox (Oracle) <willy@infradead.org>
+
+commit f2d5dcb48f7ba9e3ff249d58fc1fa963d374e66a upstream.
+
+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) <willy@infradead.org>
+Fixes: 90572890d202 ("mm: numa: Change page last {nid,pid} into {cpu,pid}")
+Reviewed-by: Rik van Riel <riel@surriel.com>
+Acked-by: Mel Gorman <mgorman@techsingularity.net>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Ingo Molnar <mingo@kernel.org>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/bounds.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/kernel/bounds.c
++++ b/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));
+       /* End of constants */
index 93161d6faef2849fecd31098f0b48ca5dd287e1c..7fb0841216ac16763449affd39881b7d6c42c6d4 100644 (file)
@@ -88,6 +88,7 @@ loop-properly-observe-rotational-flag-of-underlying-device.patch
 perf-core-fix-reentry-problem-in-perf_output_read_group.patch
 efivarfs-request-at-most-512-bytes-for-variable-names.patch
 powerpc-xor_vmx-add-mhard-float-to-cflags.patch
+bounds-support-non-power-of-two-config_nr_cpus.patch
 loop-factor-out-configuring-loop-from-status.patch
 loop-check-for-overflow-while-configuring-loop.patch
 loop-loop_set_status_from_info-check-before-assignment.patch