diff options
author | Mikulas Patocka <mpatocka@redhat.com> | 2019-04-28 00:09:53 +0200 |
---|---|---|
committer | Helge Deller <deller@gmx.de> | 2019-05-03 23:47:41 +0200 |
commit | b37d1c1898b288c69f3dc9267bc2c41af06f4a4b (patch) | |
tree | d041b4796035a447687ae8b1bc7d904c39f8729b /arch/parisc/kernel/setup.c | |
parent | d19a12906e5e558c0f6b6cfece7b7caf1012ef95 (diff) |
parisc: Use per-pagetable spinlock
PA-RISC uses a global spinlock to protect pagetable updates in the TLB
fault handlers. When multiple cores are taking TLB faults simultaneously,
the cache line containing the spinlock becomes a bottleneck.
This patch embeds the spinlock in the top level page directory, so that
every process has its own lock. It improves performance by 30% when
doing parallel compilations.
At least on the N class systems, only one PxTLB inter processor
broadcast can be active at any one time on the Merced bus. If a Merced
bus is found, this patch serializes the TLB flushes with the
pa_tlb_flush_lock spinlock.
v1: Initial patch by Mikulas
v2: Added Merced detection by Helge
v3: Revised TLB serialization by Dave & Helge
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/kernel/setup.c')
-rw-r--r-- | arch/parisc/kernel/setup.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c index d908058d05c1..e05cb2a5c16d 100644 --- a/arch/parisc/kernel/setup.c +++ b/arch/parisc/kernel/setup.c @@ -343,6 +343,12 @@ static int __init parisc_init(void) boot_cpu_data.cpu_hz / 1000000, boot_cpu_data.cpu_hz % 1000000 ); +#if defined(CONFIG_64BIT) && defined(CONFIG_SMP) + /* Don't serialize TLB flushes if we run on one CPU only. */ + if (num_online_cpus() == 1) + pa_serialize_tlb_flushes = 0; +#endif + apply_alternatives_all(); parisc_setup_cache_timing(); |