From owner-p4-projects@FreeBSD.ORG Fri Jan 25 01:34:30 2008 Return-Path: Delivered-To: p4-projects@freebsd.org Received: by hub.freebsd.org (Postfix, from userid 32767) id B988016A41B; Fri, 25 Jan 2008 01:34:30 +0000 (UTC) Delivered-To: perforce@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6605A16A419 for ; Fri, 25 Jan 2008 01:34:30 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from repoman.freebsd.org (repoman.freebsd.org [IPv6:2001:4f8:fff6::29]) by mx1.freebsd.org (Postfix) with ESMTP id 5126813C45D for ; Fri, 25 Jan 2008 01:34:30 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from repoman.freebsd.org (localhost [127.0.0.1]) by repoman.freebsd.org (8.14.1/8.14.1) with ESMTP id m0P1YUe5048088 for ; Fri, 25 Jan 2008 01:34:30 GMT (envelope-from jhb@freebsd.org) Received: (from perforce@localhost) by repoman.freebsd.org (8.14.1/8.14.1/Submit) id m0P1YUoX048085 for perforce@freebsd.org; Fri, 25 Jan 2008 01:34:30 GMT (envelope-from jhb@freebsd.org) Date: Fri, 25 Jan 2008 01:34:30 GMT Message-Id: <200801250134.m0P1YUoX048085@repoman.freebsd.org> X-Authentication-Warning: repoman.freebsd.org: perforce set sender to jhb@freebsd.org using -f From: John Baldwin To: Perforce Change Reviews Cc: Subject: PERFORCE change 134047 for review X-BeenThere: p4-projects@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: p4 projects tree changes List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Jan 2008 01:34:31 -0000 http://perforce.freebsd.org/chv.cgi?CH=134047 Change 134047 by jhb@jhb_mutex on 2008/01/25 01:33:43 - Compile (catch up to kdb_enter() API change). - Add a test for the tsleep/pause race. Affected files ... .. //depot/projects/smpng/sys/modules/crash/crash.c#42 edit Differences ... ==== //depot/projects/smpng/sys/modules/crash/crash.c#42 (text+ko) ==== @@ -52,11 +52,14 @@ #include #include #include +#include #include #include #include #include +#define KDB_WHY_CRASH "crash" + struct crash_event { const char *ev_name; void (*ev_handler)(void); @@ -86,6 +89,48 @@ /* Events. */ +static int race_wchan; + +static void +tsleep_race_fallback(void *dummy) +{ + + wakeup(&race_wchan); +} + +static void +exercise_tsleep_race(void) +{ + struct callout c; + struct bintime start, finish; + struct timeval elapsed; + int rval; + + /* + * Inline copy of tsleep() with a long DELAY() to open up the + * race window where the thread lock is dropped in between + * sleepq_add() and sleepq_*wait*(). + */ + callout_init(&c, CALLOUT_MPSAFE); + callout_reset(&c, 5 * hz, tsleep_race_fallback, NULL); + getbinuptime(&start); + sleepq_lock(&race_wchan); + DROP_GIANT(); + sleepq_add(&race_wchan, NULL, "race", SLEEPQ_SLEEP, 0); + sleepq_set_timeout(&race_wchan, 1); + DELAY(2 * 1000 * 1000); + rval = sleepq_timedwait(&race_wchan); + getbinuptime(&finish); + PICKUP_GIANT(); + printf("crash: sleepq_timedwait() returned %d\n", rval); + bintime_sub(&finish, &start); + bintime2timeval(&finish, &elapsed); + printf("crash: slept for %d.%04ld sec\n", elapsed.tv_sec, + elapsed.tv_usec / 1000); + callout_drain(&c); +} +CRASH_EVENT("exercise tsleep() race", exercise_tsleep_race); + static void sx_recurse(void) { @@ -93,7 +138,7 @@ sx_init_flags(&qux, "qux", SX_RECURSE); sx_xlock(&qux); sx_xlock(&qux); - kdb_enter("qux should be recursed"); + kdb_enter(KDB_WHY_CRASH, "qux should be recursed"); sx_xunlock(&qux); if (sx_try_xlock(&qux) == 0) panic("try_xlock failed!"); @@ -200,9 +245,9 @@ sx_init(&qux, "qux"); sx_destroy(&qux); - kdb_enter("examine qux"); + kdb_enter(KDB_WHY_CRASH, "examine qux"); sx_xlock(&qux); - kdb_enter("examine again"); + kdb_enter(KDB_WHY_CRASH, "examine again"); } CRASH_EVENT("lock destroyed sx", lock_destroyed_sx); @@ -212,9 +257,9 @@ rw_init(&baz, "baz"); rw_destroy(&baz); - kdb_enter("examine baz"); + kdb_enter(KDB_WHY_CRASH, "examine baz"); rw_wlock(&baz); - kdb_enter("examine again"); + kdb_enter(KDB_WHY_CRASH, "examine again"); } CRASH_EVENT("lock destroyed rwlock", lock_destroyed_rw); @@ -226,9 +271,9 @@ mtx_init(&test1_mtx, "test1", NULL, MTX_DEF | MTX_RECURSE); mtx_lock(&test1_mtx); mtx_destroy(&test1_mtx); - kdb_enter("examine test1"); + kdb_enter(KDB_WHY_CRASH, "examine test1"); mtx_lock(&test1_mtx); - kdb_enter("examine again"); + kdb_enter(KDB_WHY_CRASH, "examine again"); } CRASH_EVENT("lock destroyed mutex", lock_destroyed_mtx); @@ -408,11 +453,11 @@ { rw_init(&baz, "baz"); - kdb_enter("baz exists"); + kdb_enter(KDB_WHY_CRASH, "baz exists"); rw_wlock(&baz); - kdb_enter("baz has a writer"); + kdb_enter(KDB_WHY_CRASH, "baz has a writer"); rw_wunlock(&baz); - kdb_enter("baz is unlocked"); + kdb_enter(KDB_WHY_CRASH, "baz is unlocked"); rw_destroy(&baz); } CRASH_EVENT("rw_wlock", rwlock_wlock); @@ -422,11 +467,11 @@ { rw_init(&baz, "baz"); - kdb_enter("baz exists"); + kdb_enter(KDB_WHY_CRASH, "baz exists"); rw_rlock(&baz); - kdb_enter("baz has a reader"); + kdb_enter(KDB_WHY_CRASH, "baz has a reader"); rw_runlock(&baz); - kdb_enter("baz is unlocked"); + kdb_enter(KDB_WHY_CRASH, "baz is unlocked"); rw_destroy(&baz); } CRASH_EVENT("rw_rlock", rwlock_rlock); @@ -448,11 +493,11 @@ mtx_lock_spin(&test1_mtx); error = msleep_spin(&test1_mtx, &test1_mtx, "spincr", 5); printf("msleep_spin returned %d\n", error); - kdb_enter("timed out"); + kdb_enter(KDB_WHY_CRASH, "timed out"); timeout(msleep_spin_callout, NULL, 5); error = msleep_spin(&test1_mtx, &test1_mtx, "spincr2", 0); printf("msleep_spin returned %d\n", error); - kdb_enter("awoke from spin"); + kdb_enter(KDB_WHY_CRASH, "awoke from spin"); mtx_unlock_spin(&test1_mtx); mtx_destroy(&test1_mtx); } @@ -463,18 +508,18 @@ { mtx_lock(&Giant); - kdb_enter("Giant locked"); + kdb_enter(KDB_WHY_CRASH, "Giant locked"); mtx_lock(&Giant); - kdb_enter("Giant recursed"); + kdb_enter(KDB_WHY_CRASH, "Giant recursed"); mtx_unlock(&Giant); mtx_unlock(&Giant); sx_slock(&foo); - kdb_enter("foo slocked"); + kdb_enter(KDB_WHY_CRASH, "foo slocked"); sx_sunlock(&foo); sx_xlock(&foo); - kdb_enter("foo xlocked"); + kdb_enter(KDB_WHY_CRASH, "foo xlocked"); sx_xunlock(&foo); - kdb_enter("both unlocked"); + kdb_enter(KDB_WHY_CRASH, "both unlocked"); } CRASH_EVENT("ddb lock commands", ddblock_test); @@ -620,9 +665,9 @@ static void double_mtx_init(void) { - kdb_enter("about to init again"); + kdb_enter(KDB_WHY_CRASH, "about to init again"); mtx_init(&test_mtx, "test", NULL, MTX_DEF); - kdb_enter("if we haven't panic'd by now, ouch. :("); + kdb_enter(KDB_WHY_CRASH, "if we haven't panic'd by now, ouch. :("); mtx_destroy(&test_mtx); } CRASH_EVENT("re-init of test_mtx", double_mtx_init); @@ -664,18 +709,19 @@ bzero(&test2_mtx, sizeof(test2_mtx)); mtx_init(&test1_mtx, "test1", NULL, MTX_DEF); mtx_init(&test2_mtx, "test2", NULL, MTX_DEF); - kdb_enter("no order yet"); + kdb_enter(KDB_WHY_CRASH, "no order yet"); mtx_lock(&Giant); mtx_lock(&test1_mtx); mtx_lock(&test2_mtx); mtx_unlock(&test2_mtx); mtx_unlock(&test1_mtx); mtx_unlock(&Giant); - kdb_enter("test1 and test2 should be ordered"); + kdb_enter(KDB_WHY_CRASH, "test1 and test2 should be ordered"); mtx_destroy(&test1_mtx); - kdb_enter("test1 should be gone, test2 should be after Giant"); + kdb_enter(KDB_WHY_CRASH, + "test1 should be gone, test2 should be after Giant"); mtx_destroy(&test2_mtx); - kdb_enter("test1 and test2 should be gone"); + kdb_enter(KDB_WHY_CRASH, "test1 and test2 should be gone"); } CRASH_EVENT("use test1 and test2 mutexes to test witness removal", test_witness_removal); @@ -721,10 +767,10 @@ bzero(&test2_mtx, sizeof(test2_mtx)); mtx_init(&test1_mtx, "test1", NULL, MTX_DEF); mtx_init(&test2_mtx, "test2", NULL, MTX_DEF); - kdb_enter("no order yet"); + kdb_enter(KDB_WHY_CRASH, "no order yet"); status = WITNESS_DEFINEORDER(&test1_mtx, &test2_mtx); printf("Status of test1 -> test2 set order should be 0: %d\n", status); - kdb_enter("order should be test1 then test2"); + kdb_enter(KDB_WHY_CRASH, "order should be test1 then test2"); printf("Check order of test1 -> test2 should succeed.\n"); mtx_lock(&test1_mtx); witness_check(&test2_mtx); @@ -786,7 +832,7 @@ if (depth == 20) { kdb_backtrace(); - kdb_enter(__func__); + kdb_enter(KDB_WHY_CRASH, __func__); } else recurse_deep(depth + 1); }