[src/trunk]: src/sys/arch/alpha/include Shuffle fields in cpu_info for better...

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

details:   https://anonhg.NetBSD.org/src/rev/3907d7839f80
branches:  trunk
changeset: 938194:3907d7839f80
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Sep 04 01:57:29 2020 +0000

description:
Shuffle fields in cpu_info for better cache behavior.
XXX More changes to come after curlwp is overhauled.

diffstat:

 sys/arch/alpha/include/cpu.h |  64 ++++++++++++++++++++++++-------------------
 1 files changed, 35 insertions(+), 29 deletions(-)

diffs (105 lines):

diff -r 0e6bfe7e6cd7 -r 3907d7839f80 sys/arch/alpha/include/cpu.h
--- a/sys/arch/alpha/include/cpu.h      Fri Sep 04 01:56:29 2020 +0000
+++ b/sys/arch/alpha/include/cpu.h      Fri Sep 04 01:57:29 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: cpu.h,v 1.91 2020/09/03 14:27:47 thorpej Exp $ */
+/* $NetBSD: cpu.h,v 1.92 2020/09/04 01:57:29 thorpej Exp $ */
 
 /*-
  * Copyright (c) 1998, 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -84,10 +84,8 @@
 
 #if defined(_KERNEL) || defined(_KMEMUSER)
 #include <sys/cpu_data.h>
-#ifndef _KMEMUSER
 #include <sys/cctr.h>
 #include <machine/frame.h>
-#endif
 
 /*
  * Machine check information.
@@ -97,42 +95,51 @@
        volatile int mc_received;       /* machine check was received */
 };
 
+/*
+ * Per-cpu information.  Data accessed by MI code is marked [MI].
+ */
 struct cpu_info {
-       /*
-        * Public members.
-        */
-       struct lwp *ci_curlwp;          /* current owner of the processor */
-       struct lwp *ci_onproc;          /* current user LWP / kthread */
-       struct cpu_data ci_data;        /* MI per-cpu data */
-#if !defined(_KMEMUSER)
-       struct cctr_state ci_cc;        /* cycle counter state */
-       struct cpu_info *ci_next;       /* next cpu_info structure */
-       int ci_mtx_count;
-       int ci_mtx_oldspl;
+       struct lwp *ci_curlwp;          /* [MI] current owner of the cpu */
+       struct lwp *ci_onproc;          /* [MI] current user LWP / kthread */
+       struct cpu_data ci_data;        /* [MI] general per-cpu data */
+       struct cctr_state ci_cc;        /* [MI] cycle counter state */
 
-       /*
-        * Private members.
-        */
-       struct mchkinfo ci_mcinfo;      /* machine check info */
-       cpuid_t ci_cpuid;               /* our CPU ID */
+       volatile int ci_mtx_count;      /* [MI] neg count of spin mutexes */
+       volatile int ci_mtx_oldspl;     /* [MI] for spin mutex splx() */
+
+       u_long ci_intrdepth;            /* interrupt trap depth */
        struct cpu_softc *ci_softc;     /* pointer to our device */
-       u_int ci_want_resched;          /* preempt current process */
-       u_int ci_unused;                /* unused */
-       u_long ci_intrdepth;            /* interrupt trap depth */
-       struct trapframe *ci_db_regs;   /* registers for debuggers */
-       uint64_t ci_pcc_freq;           /* cpu cycles/second */
 
        struct pmap *ci_pmap;           /* currently-activated pmap */
        u_int ci_next_asn;              /* next ASN to assign */
        u_long ci_asn_gen;              /* current ASN generation */
 
-#if defined(MULTIPROCESSOR)
+       struct mchkinfo ci_mcinfo;      /* machine check info */
+
+       /*
+        * The following must be in their own cache line, as they are
+        * stored to regularly by remote CPUs.
+        */
+       volatile u_long ci_ipis         /* interprocessor interrupts pending */
+                       __aligned(64);
+       u_int   ci_want_resched;        /* [MI] preempt current process */
+
+       /*
+        * These are largely static, and will frequently be fetched
+        * by other CPUs.  For that reason, they get their own cache
+        * line, too.
+        */
+       struct cpu_info *ci_next        /* next cpu_info structure */
+                       __aligned(64);
+       cpuid_t ci_cpuid;               /* [MI] our CPU ID */
        volatile u_long ci_flags;       /* flags; see below */
-       volatile u_long ci_ipis;        /* interprocessor interrupts pending */
-#endif
-#endif /* !_KMEMUSER */
+       uint64_t ci_pcc_freq;           /* cpu cycles/second */
+       struct trapframe *ci_db_regs;   /* registers for debuggers */
 };
 
+/* Ensure cpu_info::ci_curlwp is within the signed 16-bit displacement. */
+__CTASSERT(offsetof(struct cpu_info, ci_curlwp) <= 0x7ff0);
+
 #endif /* _KERNEL || _KMEMUSER */
 
 #if defined(_KERNEL)
@@ -141,7 +148,6 @@
 #define        CPUF_PRESENT    0x02            /* CPU is present */
 #define        CPUF_RUNNING    0x04            /* CPU is running */
 #define        CPUF_PAUSED     0x08            /* CPU is paused */
-#define        CPUF_FPUSAVE    0x10            /* CPU is currently in fpusave_cpu() */
 
 extern struct cpu_info cpu_info_primary;
 extern struct cpu_info *cpu_info_list;