[PATCH] powerpc: get rid of per_cpu EEH counters

242-eeh-no-percpu-counters.patch

Remove per-cpu counters from the EEH code.  These statistics counters
are incremented at a very low frequency, and the performance gains of
per-cpu variables are negligable.  By contrast, the counters weren't
safe against cpu off/online operations, and its not worth the effort
to make them so (other than to turn them into plain globals).

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
(cherry picked from be3b5d1be053ccb41e91fa5a6f43ef5db301357d commit)

1 files changed, 23 insertions, 37 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 9e597cb7e659..136365c1f8e1 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -97,14 +97,14 @@ static DEFINE_SPINLOCK(slot_errbuf_lock);
 static int eeh_error_buf_size;
 
 /* System monitoring statistics */
-static DEFINE_PER_CPU(unsigned long, no_device);
-static DEFINE_PER_CPU(unsigned long, no_dn);
-static DEFINE_PER_CPU(unsigned long, no_cfg_addr);
-static DEFINE_PER_CPU(unsigned long, ignored_check);
-static DEFINE_PER_CPU(unsigned long, total_mmio_ffs);
-static DEFINE_PER_CPU(unsigned long, false_positives);
-static DEFINE_PER_CPU(unsigned long, ignored_failures);
-static DEFINE_PER_CPU(unsigned long, slot_resets);
+static unsigned long no_device;
+static unsigned long no_dn;
+static unsigned long no_cfg_addr;
+static unsigned long ignored_check;
+static unsigned long total_mmio_ffs;
+static unsigned long false_positives;
+static unsigned long ignored_failures;
+static unsigned long slot_resets;
 
 #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE)
 
@@ -288,13 +288,13 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         enum pci_channel_state state;
         int rc = 0;
 
-        __get_cpu_var(total_mmio_ffs)++;
+        total_mmio_ffs++;
 
         if (!eeh_subsystem_enabled)
                 return 0;
 
         if (!dn) {
-                __get_cpu_var(no_dn)++;
+                no_dn++;
                 return 0;
         }
         pdn = PCI_DN(dn);
@@ -302,7 +302,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         /* Access to IO BARs might get this far and still not want checking. */
         if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) ||
             pdn->eeh_mode & EEH_MODE_NOCHECK) {
-                __get_cpu_var(ignored_check)++;
+                ignored_check++;
 #ifdef DEBUG
                 printk ("EEH:ignored check (%x) for %s %s\n", 
                         pdn->eeh_mode, pci_name (dev), dn->full_name);
@@ -311,7 +311,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         }
 
         if (!pdn->eeh_config_addr && !pdn->eeh_pe_config_addr) {
-                __get_cpu_var(no_cfg_addr)++;
+                no_cfg_addr++;
                 return 0;
         }
 
@@ -353,7 +353,7 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         if (ret != 0) {
                 printk(KERN_WARNING "EEH: read_slot_reset_state() failed; rc=%d dn=%s\n",
                        ret, dn->full_name);
-                __get_cpu_var(false_positives)++;
+                false_positives++;
                 rc = 0;
                 goto dn_unlock;
         }
@@ -362,14 +362,14 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         if (rets[1] != 1) {
                 printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n",
                        ret, dn->full_name);
-                __get_cpu_var(false_positives)++;
+                false_positives++;
                 rc = 0;
                 goto dn_unlock;
         }
 
         /* If not the kind of error we know about, punt. */
         if (rets[0] != 2 && rets[0] != 4 && rets[0] != 5) {
-                __get_cpu_var(false_positives)++;
+                false_positives++;
                 rc = 0;
                 goto dn_unlock;
         }
@@ -377,12 +377,12 @@ int eeh_dn_check_failure(struct device_node *dn, struct pci_dev *dev)
         /* Note that config-io to empty slots may fail;
          * we recognize empty because they don't have children. */
         if ((rets[0] == 5) && (dn->child == NULL)) {
-                __get_cpu_var(false_positives)++;
+                false_positives++;
                 rc = 0;
                 goto dn_unlock;
         }
 
-        __get_cpu_var(slot_resets)++;
+        slot_resets++;
  
         /* Avoid repeated reports of this failure, including problems
          * with other functions on this device, and functions under
@@ -432,7 +432,7 @@ unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned lon
         addr = eeh_token_to_phys((unsigned long __force) token);
         dev = pci_get_device_by_addr(addr);
         if (!dev) {
-                __get_cpu_var(no_device)++;
+                no_device++;
                 return val;
         }
 
@@ -963,25 +963,9 @@ EXPORT_SYMBOL_GPL(eeh_remove_bus_device);
 
 static int proc_eeh_show(struct seq_file *m, void *v)
 {
-        unsigned int cpu;
-        unsigned long ffs = 0, positives = 0, failures = 0;
-        unsigned long resets = 0;
-        unsigned long no_dev = 0, no_dn = 0, no_cfg = 0, no_check = 0;
-
-        for_each_cpu(cpu) {
-                ffs += per_cpu(total_mmio_ffs, cpu);
-                positives += per_cpu(false_positives, cpu);
-                failures += per_cpu(ignored_failures, cpu);
-                resets += per_cpu(slot_resets, cpu);
-                no_dev += per_cpu(no_device, cpu);
-                no_dn += per_cpu(no_dn, cpu);
-                no_cfg += per_cpu(no_cfg_addr, cpu);
-                no_check += per_cpu(ignored_check, cpu);
-        }
-
         if (0 == eeh_subsystem_enabled) {
                 seq_printf(m, "EEH Subsystem is globally disabled\n");
-                seq_printf(m, "eeh_total_mmio_ffs=%ld\n", ffs);
+                seq_printf(m, "eeh_total_mmio_ffs=%ld\n", total_mmio_ffs);
         } else {
                 seq_printf(m, "EEH Subsystem is enabled\n");
                 seq_printf(m,
@@ -993,8 +977,10 @@ static int proc_eeh_show(struct seq_file *m, void *v)
                                 "eeh_false_positives=%ld\n"
                                 "eeh_ignored_failures=%ld\n"
                                 "eeh_slot_resets=%ld\n",
-                                no_dev, no_dn, no_cfg, no_check,
-                                ffs, positives, failures, resets);
+                                no_device, no_dn, no_cfg_addr, 
+                                ignored_check, total_mmio_ffs, 
+                                false_positives, ignored_failures, 
+                                slot_resets);
         }
 
         return 0;