From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from picard.linux.it (picard.linux.it [213.254.12.146]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D47B4C43217 for ; Fri, 4 Nov 2022 12:10:23 +0000 (UTC) Received: from picard.linux.it (localhost [IPv6:::1]) by picard.linux.it (Postfix) with ESMTP id 4E55B3CAEDD for ; Fri, 4 Nov 2022 13:10:22 +0100 (CET) Received: from in-2.smtp.seeweb.it (in-2.smtp.seeweb.it [217.194.8.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by picard.linux.it (Postfix) with ESMTPS id 075A03CB48D for ; Fri, 4 Nov 2022 13:06:13 +0100 (CET) Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by in-2.smtp.seeweb.it (Postfix) with ESMTPS id D012D6010F4 for ; Fri, 4 Nov 2022 10:25:38 +0100 (CET) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id C87241F8C1; Fri, 4 Nov 2022 09:25:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1667553937; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=HNg8U9QqzVIxr1gYysiuc0hi4AMtQrGun/pWV8V67F0=; b=T4WDPsbpjQ/J7oUh9QUfXVaM0x8aZXZfrHc34au2GcKytCPXKdHurPY/KH52aqruHcg/1e 9bTY8szy4xe98e6qMJ6pD8LZrMiXhtti7AN6LIWzcgGi6JnCqCRLWDdMAcWO9KbxtEi1GJ vcCby72gGY3OqMaVKOsR1/CU8Mjii2k= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7B6B01346F; Fri, 4 Nov 2022 09:25:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id bpfKGpHaZGNDfwAAMHmgww (envelope-from ); Fri, 04 Nov 2022 09:25:37 +0000 To: ltp@lists.linux.it Date: Fri, 4 Nov 2022 10:24:11 +0100 Message-Id: <20221104092411.5446-1-andrea.cervesato@suse.com> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.102.4 at in-2.smtp.seeweb.it X-Virus-Status: Clean Subject: [LTP] [PATCH v1] Correctly handle user time in setitimer01 X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Andrea Cervesato via ltp Reply-To: Andrea Cervesato Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" Since ITIMER_VIRTUAL and ITIMER_PROF are counting down in user time, we need to take in consideration CLOCK_MONOTONIC_COARSE resolution. This is requested by the syscall, since it's considering context switch from user to kernel mode by using a higher clock resolution. Signed-off-by: Andrea Cervesato --- .../kernel/syscalls/setitimer/setitimer01.c | 54 +++++++++++-------- 1 file changed, 33 insertions(+), 21 deletions(-) diff --git a/testcases/kernel/syscalls/setitimer/setitimer01.c b/testcases/kernel/syscalls/setitimer/setitimer01.c index eb62f02c6..5fcae53e8 100644 --- a/testcases/kernel/syscalls/setitimer/setitimer01.c +++ b/testcases/kernel/syscalls/setitimer/setitimer01.c @@ -8,9 +8,16 @@ /*\ * [Description] * - * Spawn a child and verify that setitimer() syscall passes, and it ends up + * Spawn a child, verify that setitimer() syscall passes and it ends up * counting inside expected boundaries. Then verify from the parent that our * syscall sent the correct signal to the child. + * + * Boundaries are choosen accordingly with system clock. In particular, when + * timer counts down in real time, CLOCK_MONOTONIC resolution has taken into + * account as our time step. When timer counts down in user time, + * CLOCK_MONOTONIC_COARSE is used. The reason is that CLOCK_MONOTONIC_COARSE + * is our system resolution in user space, since it's taking in consideration + * context switches from user to kernel space. */ #include @@ -22,7 +29,6 @@ #include "tst_safe_clocks.h" static struct itimerval *value, *ovalue; -static unsigned long time_step; static struct tcase { int which; @@ -55,9 +61,31 @@ static void set_setitimer_value(int usec, int o_usec) static void verify_setitimer(unsigned int i) { pid_t pid; - int status; - int usec = 3 * time_step; + struct timespec res; struct tcase *tc = &tcases[i]; + int status, usec, time_step, error; + + if (tc->which == ITIMER_REAL) + SAFE_CLOCK_GETRES(CLOCK_MONOTONIC, &res); + else + SAFE_CLOCK_GETRES(CLOCK_MONOTONIC_COARSE, &res); + + time_step = res.tv_nsec / 1000; + error = time_step; + + if (time_step <= 0) { + time_step = 1000; + error = 0; + } + + usec = 3 * time_step; + + tst_res(TINFO, "clock resolution: %luns, " + "time step: %ius, " + "counter time: %ius", + res.tv_nsec, + time_step, + usec); pid = SAFE_FORK(); @@ -76,7 +104,7 @@ static void verify_setitimer(unsigned int i) ovalue->it_value.tv_sec, ovalue->it_value.tv_usec); - if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_usec > usec) + if (ovalue->it_value.tv_sec != 0 || ovalue->it_value.tv_usec > usec + error) tst_res(TFAIL, "Ending counters are out of range"); for (;;) @@ -91,26 +119,10 @@ static void verify_setitimer(unsigned int i) tst_res(TFAIL, "Child: %s", tst_strstatus(status)); } -static void setup(void) -{ - struct timespec res; - - SAFE_CLOCK_GETRES(CLOCK_MONOTONIC, &res); - - time_step = res.tv_nsec / 1000; - if (time_step < 10000) - time_step = 10000; - - tst_res(TINFO, "clock resolution: %luns, time step: %luus", - res.tv_nsec, - time_step); -} - static struct tst_test test = { .tcnt = ARRAY_SIZE(tcases), .forks_child = 1, .test = verify_setitimer, - .setup = setup, .bufs = (struct tst_buffers[]) { {&value, .size = sizeof(struct itimerval)}, {&ovalue, .size = sizeof(struct itimerval)}, -- 2.35.3 -- Mailing list info: https://lists.linux.it/listinfo/ltp