From ba0c04104082ca211e108dd8eec6db2ad7676528 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Sun, 8 May 2022 19:55:13 +0200
Subject: [PATCH] Revert "parisc: Increase parisc_cache_flush_threshold
setting"
This reverts commit a58e9d0984e8dad53f17ec73ae3c1cc7f8d88151.
Triggers segfaults with 32-bit kernels on PA8500 machines.
Signed-off-by: Helge Deller <deller@gmx.de>
---
arch/parisc/kernel/cache.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 23348199f3f80..e7911225a4f89 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -403,7 +403,7 @@ void __init parisc_setup_cache_timing(void)
{
unsigned long rangetime, alltime;
unsigned long size;
- unsigned long threshold, threshold2;
+ unsigned long threshold;
alltime = mfctl(16);
flush_data_cache();
@@ -418,20 +418,8 @@ void __init parisc_setup_cache_timing(void)
alltime, size, rangetime);
threshold = L1_CACHE_ALIGN(size * alltime / rangetime);
-
- /*
- * The threshold computed above isn't very reliable since the
- * flush times depend greatly on the percentage of dirty lines
- * in the flush range. Further, the whole cache time doesn't
- * include the time to refill lines that aren't in the mm/vma
- * being flushed. By timing glibc build and checks on mako cpus,
- * the following formula seems to work reasonably well. The
- * value from the timing calculation is too small, and increases
- * build and check times by almost a factor two.
- */
- threshold2 = cache_info.dc_size * num_online_cpus();
- if (threshold2 > threshold)
- threshold = threshold2;
+ if (threshold > cache_info.dc_size)
+ threshold = cache_info.dc_size;
if (threshold)
parisc_cache_flush_threshold = threshold;
printk(KERN_INFO "Cache flush threshold set to %lu KiB\n",
--
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