[src/trunk]: src/sys/arch Move xpq_idx into cpu_info, to prevent false sharin...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/2889a903ee4a
branches:  trunk
changeset: 356304:2889a903ee4a
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sat Sep 16 09:28:38 2017 +0000

description:
Move xpq_idx into cpu_info, to prevent false sharing between CPUs. Saves
10s when doing a './build.sh -j 3 kernel=GENERIC' on xen-amd64-domU.

diffstat:

 sys/arch/x86/include/cpu.h   |   6 +++++-
 sys/arch/xen/x86/x86_xpmap.c |  22 ++++++++++------------
 2 files changed, 15 insertions(+), 13 deletions(-)

diffs (111 lines):

diff -r 006dea8079f9 -r 2889a903ee4a sys/arch/x86/include/cpu.h
--- a/sys/arch/x86/include/cpu.h        Sat Sep 16 09:04:50 2017 +0000
+++ b/sys/arch/x86/include/cpu.h        Sat Sep 16 09:28:38 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cpu.h,v 1.78 2017/08/27 09:32:13 maxv Exp $    */
+/*     $NetBSD: cpu.h,v 1.79 2017/09/16 09:28:38 maxv Exp $    */
 
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
@@ -205,6 +205,10 @@
 #endif /* __x86_64__ */
 #endif /* XEN et.al */
 
+#ifdef XEN
+       size_t          ci_xpq_idx;
+#endif
+
 #ifndef XEN
        struct evcnt ci_ipi_events[X86_NIPI];
 #else   /* XEN */
diff -r 006dea8079f9 -r 2889a903ee4a sys/arch/xen/x86/x86_xpmap.c
--- a/sys/arch/xen/x86/x86_xpmap.c      Sat Sep 16 09:04:50 2017 +0000
+++ b/sys/arch/xen/x86/x86_xpmap.c      Sat Sep 16 09:28:38 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: x86_xpmap.c,v 1.73 2017/03/18 13:35:57 maxv Exp $      */
+/*     $NetBSD: x86_xpmap.c,v 1.74 2017/09/16 09:28:38 maxv Exp $      */
 
 /*
  * Copyright (c) 2017 The NetBSD Foundation, Inc.
@@ -95,7 +95,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.73 2017/03/18 13:35:57 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: x86_xpmap.c,v 1.74 2017/09/16 09:28:38 maxv Exp $");
 
 #include "opt_xen.h"
 #include "opt_ddb.h"
@@ -134,7 +134,6 @@
 
 #define XPQUEUE_SIZE 2048
 static mmu_update_t xpq_queue_array[MAXCPUS][XPQUEUE_SIZE];
-static int xpq_idx_array[MAXCPUS];
 
 void xen_failsafe_handler(void);
 
@@ -196,16 +195,17 @@
 xpq_flush_queue(void)
 {
        mmu_update_t *xpq_queue;
-       int done = 0, ret, xpq_idx;
+       int done = 0, ret;
+       size_t xpq_idx;
 
-       xpq_idx = xpq_idx_array[curcpu()->ci_cpuid];
+       xpq_idx = curcpu()->ci_xpq_idx;
        xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
 
 retry:
        ret = HYPERVISOR_mmu_update(xpq_queue, xpq_idx, &done, DOMID_SELF);
 
        if (ret < 0 && xpq_idx != 0) {
-               printf("xpq_flush_queue: %d entries (%d successful) on "
+               printf("xpq_flush_queue: %zu entries (%d successful) on "
                    "cpu%d (%ld)\n",
                    xpq_idx, done, curcpu()->ci_index, curcpu()->ci_cpuid);
 
@@ -218,14 +218,14 @@
 
                panic("HYPERVISOR_mmu_update failed, ret: %d\n", ret);
        }
-       xpq_idx_array[curcpu()->ci_cpuid] = 0;
+       curcpu()->ci_xpq_idx = 0;
 }
 
 static inline void
 xpq_increment_idx(void)
 {
 
-       if (__predict_false(++xpq_idx_array[curcpu()->ci_cpuid] == XPQUEUE_SIZE))
+       if (__predict_false(++curcpu()->ci_xpq_idx == XPQUEUE_SIZE))
                xpq_flush_queue();
 }
 
@@ -233,7 +233,7 @@
 xpq_queue_machphys_update(paddr_t ma, paddr_t pa)
 {
        mmu_update_t *xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
-       int xpq_idx = xpq_idx_array[curcpu()->ci_cpuid];
+       size_t xpq_idx = curcpu()->ci_xpq_idx;
 
        xpq_queue[xpq_idx].ptr = ma | MMU_MACHPHYS_UPDATE;
        xpq_queue[xpq_idx].val = pa >> PAGE_SHIFT;
@@ -244,7 +244,7 @@
 xpq_queue_pte_update(paddr_t ptr, pt_entry_t val)
 {
        mmu_update_t *xpq_queue = xpq_queue_array[curcpu()->ci_cpuid];
-       int xpq_idx = xpq_idx_array[curcpu()->ci_cpuid];
+       size_t xpq_idx = curcpu()->ci_xpq_idx;
 
        xpq_queue[xpq_idx].ptr = ptr | MMU_NORMAL_PT_UPDATE;
        xpq_queue[xpq_idx].val = val;
@@ -490,8 +490,6 @@
 
        xen_init_features();
 
-       memset(xpq_idx_array, 0, sizeof(xpq_idx_array));
-
        xpmap_phys_to_machine_mapping =
            (unsigned long *)xen_start_info.mfn_list;