Date: Thu, 18 Oct 2012 14:57:11 +0000 (UTC) From: Marius Strobl <marius@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r241690 - in stable/8/sys: kern sparc64/include sparc64/sparc64 Message-ID: <201210181457.q9IEvBSC061299@svn.freebsd.org>
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Author: marius Date: Thu Oct 18 14:57:11 2012 New Revision: 241690 URL: http://svn.freebsd.org/changeset/base/241690 Log: MFC: r239864 - Unlike cache invalidation and TLB demapping IPIs, reading registers from other CPUs doesn't require locking so get rid of it. As the latter is used for the timecounter on certain machine models, using a spin lock in this case can lead to a deadlock with the upcoming callout(9) rework. - Merge r134227/r167250 from x86: Avoid cross-IPI SMP deadlock by using the smp_ipi_mtx spin lock not only for smp_rendezvous_cpus() but also for the MD cache invalidation and TLB demapping IPIs. - Mark some unused function arguments as such. Modified: stable/8/sys/kern/subr_witness.c stable/8/sys/sparc64/include/smp.h stable/8/sys/sparc64/sparc64/mp_machdep.c stable/8/sys/sparc64/sparc64/tick.c Directory Properties: stable/8/sys/ (props changed) stable/8/sys/kern/ (props changed) stable/8/sys/sparc64/ (props changed) Modified: stable/8/sys/kern/subr_witness.c ============================================================================== --- stable/8/sys/kern/subr_witness.c Thu Oct 18 14:25:33 2012 (r241689) +++ stable/8/sys/kern/subr_witness.c Thu Oct 18 14:57:11 2012 (r241690) @@ -663,9 +663,6 @@ static struct witness_order_list_entry o */ { "intrcnt", &lock_class_mtx_spin }, { "icu", &lock_class_mtx_spin }, -#if defined(SMP) && defined(__sparc64__) - { "ipi", &lock_class_mtx_spin }, -#endif #ifdef __i386__ { "allpmaps", &lock_class_mtx_spin }, { "descriptor tables", &lock_class_mtx_spin }, Modified: stable/8/sys/sparc64/include/smp.h ============================================================================== --- stable/8/sys/sparc64/include/smp.h Thu Oct 18 14:25:33 2012 (r241689) +++ stable/8/sys/sparc64/include/smp.h Thu Oct 18 14:57:11 2012 (r241690) @@ -107,7 +107,6 @@ extern cpu_ipi_single_t *cpu_ipi_single; void mp_init(u_int cpu_impl); -extern struct mtx ipi_mtx; extern struct ipi_cache_args ipi_cache_args; extern struct ipi_rd_args ipi_rd_args; extern struct ipi_tlb_args ipi_tlb_args; @@ -164,7 +163,7 @@ ipi_dcache_page_inval(void *func, vm_pad return (NULL); sched_pin(); ica = &ipi_cache_args; - mtx_lock_spin(&ipi_mtx); + mtx_lock_spin(&smp_ipi_mtx); ica->ica_mask = PCPU_GET(other_cpus); ica->ica_pa = pa; cpu_ipi_selected(ica->ica_mask, 0, (u_long)func, (u_long)ica); @@ -180,7 +179,7 @@ ipi_icache_page_inval(void *func, vm_pad return (NULL); sched_pin(); ica = &ipi_cache_args; - mtx_lock_spin(&ipi_mtx); + mtx_lock_spin(&smp_ipi_mtx); ica->ica_mask = PCPU_GET(other_cpus); ica->ica_pa = pa; cpu_ipi_selected(ica->ica_mask, 0, (u_long)func, (u_long)ica); @@ -196,7 +195,6 @@ ipi_rd(u_int cpu, void *func, u_long *va return (NULL); sched_pin(); ira = &ipi_rd_args; - mtx_lock_spin(&ipi_mtx); ira->ira_mask = 1 << cpu; ira->ira_val = val; cpu_ipi_single(cpu, 0, (u_long)func, (u_long)ira); @@ -217,7 +215,7 @@ ipi_tlb_context_demap(struct pmap *pm) return (NULL); } ita = &ipi_tlb_args; - mtx_lock_spin(&ipi_mtx); + mtx_lock_spin(&smp_ipi_mtx); ita->ita_mask = cpus; ita->ita_pmap = pm; cpu_ipi_selected(cpus, 0, (u_long)tl_ipi_tlb_context_demap, @@ -239,7 +237,7 @@ ipi_tlb_page_demap(struct pmap *pm, vm_o return (NULL); } ita = &ipi_tlb_args; - mtx_lock_spin(&ipi_mtx); + mtx_lock_spin(&smp_ipi_mtx); ita->ita_mask = cpus; ita->ita_pmap = pm; ita->ita_va = va; @@ -261,7 +259,7 @@ ipi_tlb_range_demap(struct pmap *pm, vm_ return (NULL); } ita = &ipi_tlb_args; - mtx_lock_spin(&ipi_mtx); + mtx_lock_spin(&smp_ipi_mtx); ita->ita_mask = cpus; ita->ita_pmap = pm; ita->ita_start = start; @@ -279,7 +277,19 @@ ipi_wait(void *cookie) if ((mask = cookie) != NULL) { while (*mask != 0) ; - mtx_unlock_spin(&ipi_mtx); + mtx_unlock_spin(&smp_ipi_mtx); + sched_unpin(); + } +} + +static __inline void +ipi_wait_unlocked(void *cookie) +{ + volatile cpumask_t *mask; + + if ((mask = cookie) != NULL) { + while (*mask != 0) + ; sched_unpin(); } } @@ -336,7 +346,13 @@ ipi_tlb_range_demap(struct pmap *pm __un } static __inline void -ipi_wait(void *cookie) +ipi_wait(void *cookie __unused) +{ + +} + +static __inline void +ipi_wait_unlocked(void *cookie __unused) { } Modified: stable/8/sys/sparc64/sparc64/mp_machdep.c ============================================================================== --- stable/8/sys/sparc64/sparc64/mp_machdep.c Thu Oct 18 14:25:33 2012 (r241689) +++ stable/8/sys/sparc64/sparc64/mp_machdep.c Thu Oct 18 14:57:11 2012 (r241690) @@ -112,8 +112,6 @@ struct ipi_rd_args ipi_rd_args; struct ipi_tlb_args ipi_tlb_args; struct pcb stoppcbs[MAXCPU]; -struct mtx ipi_mtx; - cpu_ipi_selected_t *cpu_ipi_selected; cpu_ipi_single_t *cpu_ipi_single; @@ -283,8 +281,6 @@ void cpu_mp_start(void) { - mtx_init(&ipi_mtx, "ipi", NULL, MTX_SPIN); - intr_setup(PIL_AST, cpu_ipi_ast, -1, NULL, NULL); intr_setup(PIL_RENDEZVOUS, (ih_func_t *)smp_rendezvous_action, -1, NULL, NULL); @@ -498,13 +494,13 @@ cpu_mp_shutdown(void) } static void -cpu_ipi_ast(struct trapframe *tf) +cpu_ipi_ast(struct trapframe *tf __unused) { } static void -cpu_ipi_stop(struct trapframe *tf) +cpu_ipi_stop(struct trapframe *tf __unused) { CTR2(KTR_SMP, "%s: stopped %d", __func__, curcpu); Modified: stable/8/sys/sparc64/sparc64/tick.c ============================================================================== --- stable/8/sys/sparc64/sparc64/tick.c Thu Oct 18 14:25:33 2012 (r241689) +++ stable/8/sys/sparc64/sparc64/tick.c Thu Oct 18 14:57:11 2012 (r241690) @@ -314,7 +314,7 @@ stick_get_timecount_mp(struct timecounte if (curcpu == 0) stick = rdstick(); else - ipi_wait(ipi_rd(0, tl_ipi_stick_rd, &stick)); + ipi_wait_unlocked(ipi_rd(0, tl_ipi_stick_rd, &stick)); sched_unpin(); return (stick); } @@ -328,7 +328,7 @@ tick_get_timecount_mp(struct timecounter if (curcpu == 0) tick = rd(tick); else - ipi_wait(ipi_rd(0, tl_ipi_tick_rd, &tick)); + ipi_wait_unlocked(ipi_rd(0, tl_ipi_tick_rd, &tick)); sched_unpin(); return (tick); }
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