From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762793Ab2KBNhl (ORCPT ); Fri, 2 Nov 2012 09:37:41 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:24583 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761181Ab2KBNfE (ORCPT ); Fri, 2 Nov 2012 09:35:04 -0400 X-Authority-Analysis: v=2.0 cv=dvhZ+ic4 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=UUALxtUs0nsA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=RaXdcHgNDvUA:10 a=1XWaLZrsAAAA:8 a=VwQbUJbxAAAA:8 a=3nbZYyFuAAAA:8 a=TgJG3LqQqHbs6aKwffAA:9 a=QEXdDO2ut3YA:10 a=aBoZ2TYS_3EA:10 a=UTB_XpHje0EA:10 a=EvKJbDF4Ut8A:10 a=jeBq3FmKZ4MA:10 a=h4wISTTLcWZLhp3VAlMA:9 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20121102133500.337156347@goodmis.org> User-Agent: quilt/0.60-1 Date: Fri, 02 Nov 2012 09:33:05 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Masami Hiramatsu , David Sharp Subject: [PATCH 13/22] tracing: Reset ring buffer when changing trace_clocks References: <20121102133251.998500247@goodmis.org> Content-Disposition: inline; filename=0013-tracing-Reset-ring-buffer-when-changing-trace_clocks.patch Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="00GvhwF7k39YY" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --00GvhwF7k39YY Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable From: David Sharp Because the "tsc" clock isn't in nanoseconds, the ring buffer must be reset when changing clocks so that incomparable timestamps don't end up in the same trace. Tested: Confirmed switching clocks resets the trace buffer. Google-Bug-Id: 6980623 Link: http://lkml.kernel.org/r/1349998076-15495-3-git-send-email-dhsharp@go= ogle.com Cc: Masami Hiramatsu Signed-off-by: David Sharp Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d7d6c52..d598ede 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4074,6 +4074,14 @@ static ssize_t tracing_clock_write(struct file *filp= , const char __user *ubuf, if (max_tr.buffer) ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); =20 + /* + * New clock may not be consistent with the previous clock. + * Reset the buffer so that it doesn't have incomparable timestamps. + */ + tracing_reset_online_cpus(&global_trace); + if (max_tr.buffer) + tracing_reset_online_cpus(&max_tr); + mutex_unlock(&trace_types_lock); =20 *fpos +=3D cnt; --=20 1.7.10.4 --00GvhwF7k39YY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQEcBAABAgAGBQJQk8wEAAoJEOdOSU1xswtMj6kH/2VeJihYmGA1XWsiCwAy55wb eQgMkW0sIGtixYsPLAuwPg6Q7xx72vwBw50Igfq02nx8A1evpdN9oeb4xX3mVTOu rUPKgvmI2CvYdd8r7xvwIjbWvzZBHy6QLqYfnQ/XwkIFPuZwNel78BHLu/ds/x1A jPD5L4HqIM7If9aelbR30YetaBzNUZRszVY6GyjDdkKY/PMWltyffBgXWqwCfkP9 CnTFURwXs5rB0BEaGbrEJSOlp3doAdvs+wzSiBalX7r0VmrFqTHhTaCRGc7LppL5 TxTucZIIXXxOo3/LtX1/XAYUSdmjCiVM1KDS2D4sOAqn3TWXoZ8IqtHVrBYx3OU= =zCf/ -----END PGP SIGNATURE----- --00GvhwF7k39YY--