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Revert "parisc: Increase parisc_cache_flush_threshold setting"
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This reverts commit a58e9d0.

Triggers segfaults with 32-bit kernels on PA8500 machines.

Signed-off-by: Helge Deller <deller@gmx.de>
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Helge Deller committed May 8, 2022
1 parent 340233d commit ba0c041
Showing 1 changed file with 3 additions and 15 deletions.
18 changes: 3 additions & 15 deletions arch/parisc/kernel/cache.c
Original file line number Diff line number Diff line change
Expand Up @@ -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();
Expand All @@ -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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