Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754636AbaAVJwP (ORCPT ); Wed, 22 Jan 2014 04:52:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35032 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751773AbaAVJwK (ORCPT ); Wed, 22 Jan 2014 04:52:10 -0500 Date: Wed, 22 Jan 2014 17:52:19 +0800 From: Dave Young To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org Subject: [BUG] sched_clock: wrong printk time stamp Message-ID: <20140122095219.GA6114@dhcp-16-126.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, With today's Linus tree, the printk time is very odd, see below qemu/efi boot log: [ 0.000000] ACPI: FACS 000000001f9e4000 000040 [ 0.000000] ACPI: APIC 000000001f9dd000 000078 (v01 OVMF OVMFEDK2 20130221 OVMF 00000099) [ 0.000000] ACPI: SSDT 000000001f9db000 000057 (v01 REDHAT OVMF 00000001 INTL 20120913) [ 0.000000] ACPI: Local APIC address 0xfee00000 [ 0.000000] Reserving 128MB of memory at 320MB for crashkernel (System RAM: 510MB) [ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00 [ 0.000000] kvm-clock: cpu 0, msr 0:1f801001, boot clock [ 1592.120520] [ffffea0000000000-ffffea00007fffff] PMD -> [ffff880013800000-ffff880013ffffff] on node 0 [ 1592.120526] Zone ranges: [ 1592.121922] DMA [mem 0x00001000-0x00ffffff] [ 1592.124493] DMA32 [mem 0x01000000-0xffffffff] [ 1592.127056] Normal empty [ 1592.128581] Movable zone start for each node The previous normal log: [ 0.000000] ACPI: FACS 000000000d5e4000 000040 [ 0.000000] ACPI: APIC 000000000d5dd000 000078 (v01 OVMF OVMFEDK2 20130221 OVMF 00000099) [ 0.000000] ACPI: SSDT 000000000d5db000 000057 (v01 REDHAT OVMF 00000001 INTL 20120913) [ 0.000000] crashkernel reservation failed - No suitable area found. [ 0.000000] kvm-clock: Using msrs 4b564d01 and 4b564d00 [ 0.000000] kvm-clock: cpu 0, msr 0:d401001, boot clock [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x00001000-0x00ffffff] [ 0.000000] DMA32 [mem 0x01000000-0xffffffff] [ 0.000000] Normal empty [ 0.000000] Movable zone start for each node [snip] [ 0.000000] ... MAX_LOCKDEP_CHAINS: 32768 [ 0.000000] ... CHAINHASH_SIZE: 16384 [ 0.000000] memory used by lock dependency info: 5855 kB [ 0.000000] per task-struct memory footprint: 1920 bytes [ 0.000000] tsc: Detected 2793.268 MHz processor [ 0.006666] Calibrating delay loop (skipped) preset value.. 5588.30 BogoMIPS (lpj=9310893) [ 0.010010] pid_max: default: 32768 minimum: 301 [ 0.013381] init_memory_mapping: [mem 0x0bd94000-0x0bd95fff] [ 0.016707] init_memory_mapping: [mem 0x0bd96000-0x0bdabfff] [ 0.020019] init_memory_mapping: [mem 0x0bdac000-0x0bdc0fff] [ 0.023206] init_memory_mapping: [mem 0x0d581000-0x0d5b0fff] I bisected the problem, it results from below commit, probably local_irq should be still disabled? -bash-4.2$ git bisect bad Bisecting: 0 revisions left to test after this (roughly 0 steps) [ef08f0fff87630d4f67ceb09514d8b444df833f8] sched/clock: Remove local_irq_disable() from the clocks Note: for the last several build steps I need manually revert 9ea4c380066fbe23fe0da7f4abfabc444f2467f4 or build will fail. Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/