From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Slutz Subject: Re: [PATCH v2 3/5] dbg_rw_guest_mem: Conditionally enable debug log output Date: Wed, 08 Jan 2014 09:28:58 -0500 Message-ID: <52CD60AA.9010607@terremark.com> References: <1389140748-26524-1-git-send-email-dslutz@verizon.com> <1389140748-26524-4-git-send-email-dslutz@verizon.com> <1389177510.4883.11.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1389177510.4883.11.camel@kazak.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell , Don Slutz Cc: Keir Fraser , Stefano Stabellini , George Dunlap , Ian Jackson , xen-devel@lists.xen.org, Jan Beulich List-Id: xen-devel@lists.xenproject.org On 01/08/14 05:38, Ian Campbell wrote: > On Tue, 2014-01-07 at 19:25 -0500, Don Slutz wrote: >> If dbg_debug is non-zero, output debug. >> >> Include put_gfn debug logging. >> >> Here is a smaple output at dbg_debug == 2: >> >> (XEN) [2014-01-07 03:20:09] gmem:addr:8f56 buf:00000000006e2020 len:$1 domid:1 toaddr:0 dp:ffff83083e5fe000 >> (XEN) [2014-01-07 03:20:09] vaddr:8f56 domid:1 >> (XEN) [2014-01-07 03:20:09] X: vaddr:8f56 domid:1 mfn:64331a >> (XEN) [2014-01-07 03:20:09] R: addr:8f56 pagecnt=1 domid:1 gfn:8 >> (XEN) [2014-01-07 03:20:09] gmem:exit:len:$0 >> (XEN) [2014-01-07 03:20:09] gmem:addr:8f57 buf:00000000006e2020 len:$1 domid:1 toaddr:0 dp:ffff83083e5fe000 >> (XEN) [2014-01-07 03:20:09] vaddr:8f57 domid:1 >> (XEN) [2014-01-07 03:20:09] X: vaddr:8f57 domid:1 mfn:64331a >> (XEN) [2014-01-07 03:20:09] R: addr:8f57 pagecnt=1 domid:1 gfn:8 >> (XEN) [2014-01-07 03:20:09] gmem:exit:len:$0 >> (XEN) [2014-01-07 03:20:09] gmem:addr:6ae9168b buf:00000000006e2020 len:$2 domid:1 toaddr:0 dp:ffff83083e5fe000 >> (XEN) [2014-01-07 03:20:09] vaddr:6ae9168b domid:1 >> (XEN) [2014-01-07 03:20:09] X: vaddr:6ae9168b domid:1 mfn:ffffffffffffffff >> (XEN) [2014-01-07 03:20:09] R: domid:1 gfn:6ae91 >> (XEN) [2014-01-07 03:20:09] gmem:exit:len:$2 >> >> Signed-off-by: Don Slutz >> --- >> xen/arch/x86/debug.c | 54 +++++++++++++++++++++++++--------------------------- >> 1 file changed, 26 insertions(+), 28 deletions(-) >> >> diff --git a/xen/arch/x86/debug.c b/xen/arch/x86/debug.c >> index ba6a64d..777e5ba 100644 >> --- a/xen/arch/x86/debug.c >> +++ b/xen/arch/x86/debug.c >> @@ -30,16 +30,9 @@ >> * gdbsx, etc.. >> */ >> >> -#ifdef XEN_KDB_CONFIG >> -#include "../kdb/include/kdbdefs.h" >> -#include "../kdb/include/kdbproto.h" >> -#define DBGP(...) {(kdbdbg) ? kdbp(__VA_ARGS__):0;} >> -#define DBGP1(...) {(kdbdbg>1) ? kdbp(__VA_ARGS__):0;} >> -#define DBGP2(...) {(kdbdbg>2) ? kdbp(__VA_ARGS__):0;} >> -#else >> -#define DBGP1(...) ((void)0) >> -#define DBGP2(...) ((void)0) >> -#endif >> +static volatile int dbg_debug; > Using volatile is almost always wrong. Why do you think it is needed > here? This was from Mukesh Rathor: http://lists.xen.org/archives/html/xen-devel/2014-01/msg00426.html I saw no reason to make it volatile, but maybe "kdb" needs this? Happy to change any way you want. > If anything this variable is exactly the opposite, i..e __read_mostly or > even const (given that I can't see anything which writes it I suppose > this is a compile time setting?) That has been how I have been testing it so far (changing the source to set values). Mukesh claims to be able to change it at will. Not sure how const may effect this. -Don Slutz > Ian. >