[IA64] __per_cpu_idtrs[] is a memory hog

__per_cpu_idtrs is statically allocated ... on CONFIG_NR_CPUS=4096
systems it hogs 16MB of memory. This is way too much for a quite
probably unused facility (only KVM uses dynamic TR registers).

Change to an array of pointers, and allocate entries as needed on
a per cpu basis.  Change the name too as the __per_cpu_ prefix is
confusing (this isn't a classic <linux/percpu.h> type object).

Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h
index 85d965c..23cce99 100644 (file)
--- a/arch/ia64/include/asm/tlb.h
+++ b/arch/ia64/include/asm/tlb.h
@@ -74,7 +74,7 @@ struct ia64_tr_entry {
 extern int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size);
 extern void ia64_ptr_entry(u64 target_mask, int slot);
 
-extern struct ia64_tr_entry __per_cpu_idtrs[NR_CPUS][2][IA64_TR_ALLOC_MAX];
+extern struct ia64_tr_entry *ia64_idtrs[NR_CPUS];
 
 /*
  region register macros

diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index 32f2639..378b483 100644 (file)
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -1225,9 +1225,12 @@ static void mca_insert_tr(u64 iord)
        unsigned long psr;
        int cpu = smp_processor_id();
 
+       if (!ia64_idtrs[cpu])
+               return;
+
        psr = ia64_clear_ic();
        for (i = IA64_TR_ALLOC_BASE; i < IA64_TR_ALLOC_MAX; i++) {
-               p = &__per_cpu_idtrs[cpu][iord-1][i];
+               p = ia64_idtrs[cpu] + (iord - 1) * IA64_TR_ALLOC_MAX;
                if (p->pte & 0x1) {
                        old_rr = ia64_get_rr(p->ifa);
                        if (old_rr != p->rr) {

diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index ee09d26..f3de9d7 100644 (file)
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -48,7 +48,7 @@ DEFINE_PER_CPU(u8, ia64_need_tlb_flush);
 DEFINE_PER_CPU(u8, ia64_tr_num);  /*Number of TR slots in current processor*/
 DEFINE_PER_CPU(u8, ia64_tr_used); /*Max Slot number used by kernel*/
 
-struct ia64_tr_entry __per_cpu_idtrs[NR_CPUS][2][IA64_TR_ALLOC_MAX];
+struct ia64_tr_entry *ia64_idtrs[NR_CPUS];
 
 /*
  * Initializes the ia64_ctx.bitmap array based on max_ctx+1.
@@ -429,10 +429,16 @@ int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size)
        struct ia64_tr_entry *p;
        int cpu = smp_processor_id();
 
+       if (!ia64_idtrs[cpu]) {
+               ia64_idtrs[cpu] = kmalloc(2 * IA64_TR_ALLOC_MAX *
+                               sizeof (struct ia64_tr_entry), GFP_KERNEL);
+               if (!ia64_idtrs[cpu])
+                       return -ENOMEM;
+       }
        r = -EINVAL;
        /*Check overlap with existing TR entries*/
        if (target_mask & 0x1) {
-               p = &__per_cpu_idtrs[cpu][0][0];
+               p = ia64_idtrs[cpu];
                for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu);
                                                                i++, p++) {
                        if (p->pte & 0x1)
@@ -444,7 +450,7 @@ int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size)
                }
        }
        if (target_mask & 0x2) {
-               p = &__per_cpu_idtrs[cpu][1][0];
+               p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX;
                for (i = IA64_TR_ALLOC_BASE; i <= per_cpu(ia64_tr_used, cpu);
                                                                i++, p++) {
                        if (p->pte & 0x1)
@@ -459,16 +465,16 @@ int ia64_itr_entry(u64 target_mask, u64 va, u64 pte, u64 log_size)
        for (i = IA64_TR_ALLOC_BASE; i < per_cpu(ia64_tr_num, cpu); i++) {
                switch (target_mask & 0x3) {
                case 1:
-                       if (!(__per_cpu_idtrs[cpu][0][i].pte & 0x1))
+                       if (!((ia64_idtrs[cpu] + i)->pte & 0x1))
                                goto found;
                        continue;
                case 2:
-                       if (!(__per_cpu_idtrs[cpu][1][i].pte & 0x1))
+                       if (!((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1))
                                goto found;
                        continue;
                case 3:
-                       if (!(__per_cpu_idtrs[cpu][0][i].pte & 0x1) &&
-                               !(__per_cpu_idtrs[cpu][1][i].pte & 0x1))
+                       if (!((ia64_idtrs[cpu] + i)->pte & 0x1) &&
+                           !((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1))
                                goto found;
                        continue;
                default:
@@ -488,7 +494,7 @@ found:
        if (target_mask & 0x1) {
                ia64_itr(0x1, i, va, pte, log_size);
                ia64_srlz_i();
-               p = &__per_cpu_idtrs[cpu][0][i];
+               p = ia64_idtrs[cpu] + i;
                p->ifa = va;
                p->pte = pte;
                p->itir = log_size << 2;
@@ -497,7 +503,7 @@ found:
        if (target_mask & 0x2) {
                ia64_itr(0x2, i, va, pte, log_size);
                ia64_srlz_i();
-               p = &__per_cpu_idtrs[cpu][1][i];
+               p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i;
                p->ifa = va;
                p->pte = pte;
                p->itir = log_size << 2;
@@ -528,7 +534,7 @@ void ia64_ptr_entry(u64 target_mask, int slot)
                return;
 
        if (target_mask & 0x1) {
-               p = &__per_cpu_idtrs[cpu][0][slot];
+               p = ia64_idtrs[cpu] + slot;
                if ((p->pte&0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) {
                        p->pte = 0;
                        ia64_ptr(0x1, p->ifa, p->itir>>2);
@@ -537,7 +543,7 @@ void ia64_ptr_entry(u64 target_mask, int slot)
        }
 
        if (target_mask & 0x2) {
-               p = &__per_cpu_idtrs[cpu][1][slot];
+               p = ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + slot;
                if ((p->pte & 0x1) && is_tr_overlap(p, p->ifa, p->itir>>2)) {
                        p->pte = 0;
                        ia64_ptr(0x2, p->ifa, p->itir>>2);
@@ -546,8 +552,8 @@ void ia64_ptr_entry(u64 target_mask, int slot)
        }
 
        for (i = per_cpu(ia64_tr_used, cpu); i >= IA64_TR_ALLOC_BASE; i--) {
-               if ((__per_cpu_idtrs[cpu][0][i].pte & 0x1) ||
-                               (__per_cpu_idtrs[cpu][1][i].pte & 0x1))
+               if (((ia64_idtrs[cpu] + i)->pte & 0x1) ||
+                   ((ia64_idtrs[cpu] + IA64_TR_ALLOC_MAX + i)->pte & 0x1))
                        break;
        }
        per_cpu(ia64_tr_used, cpu) = i;