From owner-svn-src-head@FreeBSD.ORG Sat Jun 23 09:33:07 2012 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2D9EE106566B; Sat, 23 Jun 2012 09:33:07 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c]) by mx1.freebsd.org (Postfix) with ESMTP id 16E268FC17; Sat, 23 Jun 2012 09:33:07 +0000 (UTC) Received: from svn.freebsd.org (localhost [127.0.0.1]) by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q5N9X6Bl032385; Sat, 23 Jun 2012 09:33:06 GMT (envelope-from kib@svn.freebsd.org) Received: (from kib@localhost) by svn.freebsd.org (8.14.4/8.14.4/Submit) id q5N9X6gr032380; Sat, 23 Jun 2012 09:33:06 GMT (envelope-from kib@svn.freebsd.org) Message-Id: <201206230933.q5N9X6gr032380@svn.freebsd.org> From: Konstantin Belousov Date: Sat, 23 Jun 2012 09:33:06 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Subject: svn commit: r237474 - in head/sys: kern sys X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 23 Jun 2012 09:33:07 -0000 Author: kib Date: Sat Jun 23 09:33:06 2012 New Revision: 237474 URL: http://svn.freebsd.org/changeset/base/237474 Log: Stop updating the struct vdso_timehands from even handler executed in the scheduled task from tc_windup(). Do it directly from tc_windup in interrupt context [1]. Establish the permanent mapping of the shared page into the kernel address space, avoiding the potential need to sleep waiting for allocation of sf buffer during vdso_timehands update. As a consequence, shared_page_write_start() and shared_page_write_end() functions are not needed anymore. Guess and memorize the pointers to native host and compat32 sysentvec during initialization, to avoid the need to get shared_page_alloc_sx lock during the update. In tc_fill_vdso_timehands(), do not loop waiting for timehands generation to stabilize, since vdso_timehands is written in the same interrupt context which wrote timehands. Requested by: mav [1] MFC after: 29 days Modified: head/sys/kern/kern_exec.c head/sys/kern/kern_tc.c head/sys/sys/sysent.h head/sys/sys/vdso.h Modified: head/sys/kern/kern_exec.c ============================================================================== --- head/sys/kern/kern_exec.c Sat Jun 23 08:36:49 2012 (r237473) +++ head/sys/kern/kern_exec.c Sat Jun 23 09:33:06 2012 (r237474) @@ -1517,42 +1517,13 @@ exec_unregister(execsw_arg) static struct sx shared_page_alloc_sx; static vm_object_t shared_page_obj; static int shared_page_free; - -struct sf_buf * -shared_page_write_start(int base) -{ - vm_page_t m; - struct sf_buf *s; - - VM_OBJECT_LOCK(shared_page_obj); - m = vm_page_grab(shared_page_obj, OFF_TO_IDX(base), VM_ALLOC_RETRY); - VM_OBJECT_UNLOCK(shared_page_obj); - s = sf_buf_alloc(m, SFB_DEFAULT); - return (s); -} - -void -shared_page_write_end(struct sf_buf *sf) -{ - vm_page_t m; - - m = sf_buf_page(sf); - sf_buf_free(sf); - VM_OBJECT_LOCK(shared_page_obj); - vm_page_wakeup(m); - VM_OBJECT_UNLOCK(shared_page_obj); -} +char *shared_page_mapping; void shared_page_write(int base, int size, const void *data) { - struct sf_buf *sf; - vm_offset_t sk; - sf = shared_page_write_start(base); - sk = sf_buf_kva(sf); - bcopy(data, (void *)(sk + (base & PAGE_MASK)), size); - shared_page_write_end(sf); + bcopy(data, shared_page_mapping + base, size); } static int @@ -1596,6 +1567,7 @@ static void shared_page_init(void *dummy __unused) { vm_page_t m; + vm_offset_t addr; sx_init(&shared_page_alloc_sx, "shpsx"); shared_page_obj = vm_pager_allocate(OBJT_PHYS, 0, PAGE_SIZE, @@ -1605,25 +1577,24 @@ shared_page_init(void *dummy __unused) VM_ALLOC_ZERO); m->valid = VM_PAGE_BITS_ALL; VM_OBJECT_UNLOCK(shared_page_obj); + addr = kmem_alloc_nofault(kernel_map, PAGE_SIZE); + pmap_qenter(addr, &m, 1); + shared_page_mapping = (char *)addr; } SYSINIT(shp, SI_SUB_EXEC, SI_ORDER_FIRST, (sysinit_cfunc_t)shared_page_init, NULL); static void -timehands_update(void *arg) +timehands_update(struct sysentvec *sv) { - struct sysentvec *sv; - struct sf_buf *sf; struct vdso_timehands th; struct vdso_timekeep *tk; uint32_t enabled, idx; - sv = arg; - sx_xlock(&shared_page_alloc_sx); enabled = tc_fill_vdso_timehands(&th); - sf = shared_page_write_start(sv->sv_timekeep_off); - tk = (void *)(sf_buf_kva(sf) + (sv->sv_timekeep_off & PAGE_MASK)); + tk = (struct vdso_timekeep *)(shared_page_mapping + + sv->sv_timekeep_off); idx = sv->sv_timekeep_curr; atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); if (++idx >= VDSO_TH_NUM) @@ -1637,25 +1608,19 @@ timehands_update(void *arg) tk->tk_enabled = enabled; atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); tk->tk_current = idx; - shared_page_write_end(sf); - sx_xunlock(&shared_page_alloc_sx); } #ifdef COMPAT_FREEBSD32 static void -timehands_update32(void *arg) +timehands_update32(struct sysentvec *sv) { - struct sysentvec *sv; - struct sf_buf *sf; struct vdso_timekeep32 *tk; struct vdso_timehands32 th; uint32_t enabled, idx; - sv = arg; - sx_xlock(&shared_page_alloc_sx); enabled = tc_fill_vdso_timehands32(&th); - sf = shared_page_write_start(sv->sv_timekeep_off); - tk = (void *)(sf_buf_kva(sf) + (sv->sv_timekeep_off & PAGE_MASK)); + tk = (struct vdso_timekeep32 *)(shared_page_mapping + + sv->sv_timekeep_off); idx = sv->sv_timekeep_curr; atomic_store_rel_32(&tk->tk_th[idx].th_gen, 0); if (++idx >= VDSO_TH_NUM) @@ -1669,11 +1634,32 @@ timehands_update32(void *arg) tk->tk_enabled = enabled; atomic_store_rel_32(&tk->tk_th[idx].th_gen, sv->sv_timekeep_gen); tk->tk_current = idx; - shared_page_write_end(sf); - sx_xunlock(&shared_page_alloc_sx); } #endif +/* + * This is hackish, but easiest way to avoid creating list structures + * that needs to be iterated over from the hardclock interrupt + * context. + */ +static struct sysentvec *host_sysentvec; +#ifdef COMPAT_FREEBSD32 +static struct sysentvec *compat32_sysentvec; +#endif + +void +timekeep_push_vdso(void) +{ + + if (host_sysentvec != NULL && host_sysentvec->sv_timekeep_base != 0) + timehands_update(host_sysentvec); +#ifdef COMPAT_FREEBSD32 + if (compat32_sysentvec != NULL && + compat32_sysentvec->sv_timekeep_base != 0) + timehands_update32(compat32_sysentvec); +#endif +} + void exec_sysvec_init(void *param) { @@ -1688,29 +1674,32 @@ exec_sysvec_init(void *param) sv->sv_shared_page_obj = shared_page_obj; sv->sv_sigcode_base = sv->sv_shared_page_base + shared_page_fill(*(sv->sv_szsigcode), 16, sv->sv_sigcode); + if ((sv->sv_flags & SV_ABI_MASK) != SV_ABI_FREEBSD) + return; tk_ver = VDSO_TK_VER_CURR; #ifdef COMPAT_FREEBSD32 if ((sv->sv_flags & SV_ILP32) != 0) { tk_base = shared_page_alloc(sizeof(struct vdso_timekeep32) + sizeof(struct vdso_timehands32) * VDSO_TH_NUM, 16); KASSERT(tk_base != -1, ("tk_base -1 for 32bit")); - EVENTHANDLER_REGISTER(tc_windup, timehands_update32, sv, - EVENTHANDLER_PRI_ANY); shared_page_write(tk_base + offsetof(struct vdso_timekeep32, tk_ver), sizeof(uint32_t), &tk_ver); + KASSERT(compat32_sysentvec == 0, + ("Native compat32 already registered")); + compat32_sysentvec = sv; } else { #endif tk_base = shared_page_alloc(sizeof(struct vdso_timekeep) + sizeof(struct vdso_timehands) * VDSO_TH_NUM, 16); KASSERT(tk_base != -1, ("tk_base -1 for native")); - EVENTHANDLER_REGISTER(tc_windup, timehands_update, sv, - EVENTHANDLER_PRI_ANY); shared_page_write(tk_base + offsetof(struct vdso_timekeep, tk_ver), sizeof(uint32_t), &tk_ver); + KASSERT(host_sysentvec == 0, ("Native already registered")); + host_sysentvec = sv; #ifdef COMPAT_FREEBSD32 } #endif sv->sv_timekeep_base = sv->sv_shared_page_base + tk_base; sv->sv_timekeep_off = tk_base; - EVENTHANDLER_INVOKE(tc_windup); + timekeep_push_vdso(); } Modified: head/sys/kern/kern_tc.c ============================================================================== --- head/sys/kern/kern_tc.c Sat Jun 23 08:36:49 2012 (r237473) +++ head/sys/kern/kern_tc.c Sat Jun 23 09:33:06 2012 (r237474) @@ -31,7 +31,6 @@ __FBSDID("$FreeBSD$"); #include #include #include -#include #include #include #include @@ -121,12 +120,8 @@ SYSCTL_INT(_kern_timecounter, OID_AUTO, ×tepwarnings, 0, "Log time steps"); static void tc_windup(void); -static void tc_windup_push_vdso(void *ctx, int pending); static void cpu_tick_calibrate(int); -static struct task tc_windup_push_vdso_task = TASK_INITIALIZER(0, - tc_windup_push_vdso, 0); - static int sysctl_kern_boottime(SYSCTL_HANDLER_ARGS) { @@ -1367,7 +1362,7 @@ tc_windup(void) #endif timehands = th; - taskqueue_enqueue_fast(taskqueue_fast, &tc_windup_push_vdso_task); + timekeep_push_vdso(); } /* Report or change the active timecounter hardware. */ @@ -1394,7 +1389,7 @@ sysctl_kern_timecounter_hardware(SYSCTL_ (void)newtc->tc_get_timecount(newtc); timecounter = newtc; - EVENTHANDLER_INVOKE(tc_windup); + timekeep_push_vdso(); return (0); } return (EINVAL); @@ -1865,7 +1860,7 @@ sysctl_fast_gettime(SYSCTL_HANDLER_ARGS) if (error != 0) return (error); vdso_th_enable = old_vdso_th_enable; - EVENTHANDLER_INVOKE(tc_windup); + timekeep_push_vdso(); return (0); } SYSCTL_PROC(_kern_timecounter, OID_AUTO, fast_gettime, @@ -1877,19 +1872,15 @@ tc_fill_vdso_timehands(struct vdso_timeh { struct timehands *th; uint32_t enabled; - int gen; - do { - th = timehands; - gen = th->th_generation; - vdso_th->th_algo = VDSO_TH_ALGO_1; - vdso_th->th_scale = th->th_scale; - vdso_th->th_offset_count = th->th_offset_count; - vdso_th->th_counter_mask = th->th_counter->tc_counter_mask; - vdso_th->th_offset = th->th_offset; - vdso_th->th_boottime = boottimebin; - enabled = cpu_fill_vdso_timehands(vdso_th); - } while (gen == 0 || timehands->th_generation != gen); + th = timehands; + vdso_th->th_algo = VDSO_TH_ALGO_1; + vdso_th->th_scale = th->th_scale; + vdso_th->th_offset_count = th->th_offset_count; + vdso_th->th_counter_mask = th->th_counter->tc_counter_mask; + vdso_th->th_offset = th->th_offset; + vdso_th->th_boottime = boottimebin; + enabled = cpu_fill_vdso_timehands(vdso_th); if (!vdso_th_enable) enabled = 0; return (enabled); @@ -1901,30 +1892,19 @@ tc_fill_vdso_timehands32(struct vdso_tim { struct timehands *th; uint32_t enabled; - int gen; - do { - th = timehands; - gen = th->th_generation; - vdso_th32->th_algo = VDSO_TH_ALGO_1; - *(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale; - vdso_th32->th_offset_count = th->th_offset_count; - vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask; - vdso_th32->th_offset.sec = th->th_offset.sec; - *(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac; - vdso_th32->th_boottime.sec = boottimebin.sec; - *(uint64_t *)&vdso_th32->th_boottime.frac[0] = boottimebin.frac; - enabled = cpu_fill_vdso_timehands32(vdso_th32); - } while (gen == 0 || timehands->th_generation != gen); + th = timehands; + vdso_th32->th_algo = VDSO_TH_ALGO_1; + *(uint64_t *)&vdso_th32->th_scale[0] = th->th_scale; + vdso_th32->th_offset_count = th->th_offset_count; + vdso_th32->th_counter_mask = th->th_counter->tc_counter_mask; + vdso_th32->th_offset.sec = th->th_offset.sec; + *(uint64_t *)&vdso_th32->th_offset.frac[0] = th->th_offset.frac; + vdso_th32->th_boottime.sec = boottimebin.sec; + *(uint64_t *)&vdso_th32->th_boottime.frac[0] = boottimebin.frac; + enabled = cpu_fill_vdso_timehands32(vdso_th32); if (!vdso_th_enable) enabled = 0; return (enabled); } #endif - -static void -tc_windup_push_vdso(void *ctx, int pending) -{ - - EVENTHANDLER_INVOKE(tc_windup); -} Modified: head/sys/sys/sysent.h ============================================================================== --- head/sys/sys/sysent.h Sat Jun 23 08:36:49 2012 (r237473) +++ head/sys/sys/sysent.h Sat Jun 23 09:33:06 2012 (r237474) @@ -265,8 +265,6 @@ int shared_page_alloc(int size, int alig int shared_page_fill(int size, int align, const void *data); void shared_page_write(int base, int size, const void *data); void exec_sysvec_init(void *param); -struct sf_buf *shared_page_write_start(int base); -void shared_page_write_end(struct sf_buf *sf); #define INIT_SYSENTVEC(name, sv) \ SYSINIT(name, SI_SUB_EXEC, SI_ORDER_ANY, \ Modified: head/sys/sys/vdso.h ============================================================================== --- head/sys/sys/vdso.h Sat Jun 23 08:36:49 2012 (r237473) +++ head/sys/sys/vdso.h Sat Jun 23 09:33:06 2012 (r237474) @@ -29,7 +29,6 @@ #define _SYS_VDSO_H #include -#include #include struct vdso_timehands { @@ -74,6 +73,8 @@ u_int __vdso_gettc(const struct vdso_tim #ifdef _KERNEL +void timekeep_push_vdso(void); + uint32_t tc_fill_vdso_timehands(struct vdso_timehands *vdso_th); /* @@ -86,9 +87,6 @@ uint32_t tc_fill_vdso_timehands(struct v */ uint32_t cpu_fill_vdso_timehands(struct vdso_timehands *vdso_th); -typedef void (*tc_windup_fn)(void *); -EVENTHANDLER_DECLARE(tc_windup, tc_windup_fn); - #define VDSO_TH_NUM 4 #ifdef COMPAT_FREEBSD32