From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Zaretskii To: kettenis@wins.uva.nl Cc: gdb@sources.redhat.com Subject: Re: [RFC] Unified watchpoints for x86 platforms Date: Tue, 27 Feb 2001 10:57:00 -0000 Message-id: <200102271857.NAA05225@indy.delorie.com> References: <200009070855.EAA00749@albacore> <200009071500.LAA07756@indy.delorie.com> <200009081529.e88FTjx15960@debye.wins.uva.nl> <200102101533.KAA10417@indy.delorie.com> <200102151146.NAA28431@is.elta.co.il> <1010215184135.ZM8866@ocotillo.lan> <200102152125.QAA15548@indy.delorie.com> <5melwzd0qr.fsf@jtc.redback.com> <1010216000953.ZM9629@ocotillo.lan> <200102241814.NAA00148@indy.delorie.com> X-SW-Source: 2001-02/msg00418.html > From: Mark Kettenis > Date: 27 Feb 2001 12:28:43 +0100 > > > > For those who might not remember what those flags are: Each > > hardware-assisted breakpoint or watchpoint should be enabled by > > setting bits in the DR7 register. A watchpoint can be enabled locally > > or globally, depending on which bit in DR7 is set for that watchpoint. > > A watchpoint that is enabled locally will only break if it is hit in > > the current task. A watchpoint that is enabled globally will break in > > any task. > > Makes me wonder if global watchpoints would really work if hardware > task switching isn't used. I guess the answer depends on how exactly is the software task switching implemented. Namely, does it reset the GE and LE bits in DR7 when the task switch happens. > In principle a GDB command to control whether to enable watchpoints > locally or globally wouldn't be a bad idea. But I don't know any > targets where this would be useful. So if it isn't useful for DJGPP > either, I wouldn't bother. A comment about the issue at the right > spot would be nice though. That was my tendency as well. Thanks for the feedback.