| Message ID | 1364536477-7844-1-git-send-email-djkurtz@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 29, 2013 at 01:54:37PM +0800, Daniel Kurtz wrote: > According to the opengl glx_sync_control spec, the Unadjusted System Time > (or UST) is a 64-bit monotonically increasing counter that is available > throughout the system: > http://www.opengl.org/registry/specs/OML/glx_sync_control.txt > > Therefore, sending 0, even in this corner case, is out of spec. > Instead, just return FALSE indicating that the operation could not be > completed. The problem is that ends up sending BadDrawable back to the client, which ends up killing many clients and a compositor or two due to the unexpected error. Would you prefer querying pipe 0 in this case for the UST? -Chris
On Fri, Mar 29, 2013 at 2:07 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote: > On Fri, Mar 29, 2013 at 01:54:37PM +0800, Daniel Kurtz wrote: >> According to the opengl glx_sync_control spec, the Unadjusted System Time >> (or UST) is a 64-bit monotonically increasing counter that is available >> throughout the system: >> http://www.opengl.org/registry/specs/OML/glx_sync_control.txt >> >> Therefore, sending 0, even in this corner case, is out of spec. >> Instead, just return FALSE indicating that the operation could not be >> completed. > > The problem is that ends up sending BadDrawable back to the client, > which ends up killing many clients and a compositor or two due to the > unexpected error. > > Would you prefer querying pipe 0 in this case for the UST? For us it comes down to the fact that we'd like something monotonous. So yes querying pipe 0 could work if it's enabled. But I wonder what do you do when you have no enabled pipe though? Return the last UST? Stéphane
On Fri, Mar 29, 2013 at 03:13:35AM -0700, Stéphane Marchesin wrote: > On Fri, Mar 29, 2013 at 2:07 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote: > > On Fri, Mar 29, 2013 at 01:54:37PM +0800, Daniel Kurtz wrote: > >> According to the opengl glx_sync_control spec, the Unadjusted System Time > >> (or UST) is a 64-bit monotonically increasing counter that is available > >> throughout the system: > >> http://www.opengl.org/registry/specs/OML/glx_sync_control.txt > >> > >> Therefore, sending 0, even in this corner case, is out of spec. > >> Instead, just return FALSE indicating that the operation could not be > >> completed. > > > > The problem is that ends up sending BadDrawable back to the client, > > which ends up killing many clients and a compositor or two due to the > > unexpected error. > > > > Would you prefer querying pipe 0 in this case for the UST? > > For us it comes down to the fact that we'd like something monotonous. > So yes querying pipe 0 could work if it's enabled. But I wonder what > do you do when you have no enabled pipe though? Return the last UST? That's a problem as we would need a running pipe, which is not guaranteed. I wonder if CLOCK_MONOTONIC would suffice? -Chris
On Fri, Mar 29, 2013 at 5:54 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote: > On Fri, Mar 29, 2013 at 03:13:35AM -0700, Stéphane Marchesin wrote: >> On Fri, Mar 29, 2013 at 2:07 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote: >> > On Fri, Mar 29, 2013 at 01:54:37PM +0800, Daniel Kurtz wrote: >> >> According to the opengl glx_sync_control spec, the Unadjusted System Time >> >> (or UST) is a 64-bit monotonically increasing counter that is available >> >> throughout the system: >> >> http://www.opengl.org/registry/specs/OML/glx_sync_control.txt >> >> >> >> Therefore, sending 0, even in this corner case, is out of spec. >> >> Instead, just return FALSE indicating that the operation could not be >> >> completed. >> > >> > The problem is that ends up sending BadDrawable back to the client, >> > which ends up killing many clients and a compositor or two due to the >> > unexpected error. >> > >> > Would you prefer querying pipe 0 in this case for the UST? >> >> For us it comes down to the fact that we'd like something monotonous. >> So yes querying pipe 0 could work if it's enabled. But I wonder what >> do you do when you have no enabled pipe though? Return the last UST? > > That's a problem as we would need a running pipe, which is not > guaranteed. I wonder if CLOCK_MONOTONIC would suffice? Yeah that's what I had in mind. Would that work for you? Stéphane
On Fri, Mar 29, 2013 at 09:54:50AM -0700, Stéphane Marchesin wrote: > On Fri, Mar 29, 2013 at 5:54 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote: > > That's a problem as we would need a running pipe, which is not > > guaranteed. I wonder if CLOCK_MONOTONIC would suffice? > > Yeah that's what I had in mind. Would that work for you? I think so, the value looks like it should be consistent with the kernel. I've applied a patch to return the CLOCK_MONOTONIC usec, thanks. -Chris
diff --git a/src/intel_dri.c b/src/intel_dri.c index f351203..179bfb7 100644 --- a/src/intel_dri.c +++ b/src/intel_dri.c @@ -1339,12 +1339,9 @@ I830DRI2GetMSC(DrawablePtr draw, CARD64 *ust, CARD64 *msc) drmVBlank vbl; int ret, pipe = I830DRI2DrawablePipe(draw); - /* Drawable not displayed, make up a value */ - if (pipe == -1) { - *ust = 0; - *msc = 0; - return TRUE; - } + /* Drawable not displayed, return FALSE */ + if (pipe == -1) + return FALSE; vbl.request.type = DRM_VBLANK_RELATIVE | pipe_select(pipe); vbl.request.sequence = 0;
According to the opengl glx_sync_control spec, the Unadjusted System Time (or UST) is a 64-bit monotonically increasing counter that is available throughout the system: http://www.opengl.org/registry/specs/OML/glx_sync_control.txt Therefore, sending 0, even in this corner case, is out of spec. Instead, just return FALSE indicating that the operation could not be completed. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> --- src/intel_dri.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)