vgsp-sema r568: gate a partially-resolved launch on any unexecuted CE write

The page-level dstpend guard is blind when the launch's argument base was
dropped (GRFILL-DROP): the launch's data set then lacks the buffer's pages.
r571 mail: the VADD's copy-in ran at 319818.68 while the b H2D executed at
319820.16 (its base dropped, 9 pages unresolved) - the engine computed
c = a + 0 again, same signature as r567/r568. r570 passed only because the
page-level guard happened to catch it there.

svc_copy_pending(): true when any active opdef slot belongs to a CE
channel (a withheld CE release = a device write that has not executed;
GR channels excluded so a launch's own withheld release cannot defer
itself). A launch that is partially resolved (gr_arg_partial or
gr_dropped > 0) now defers while any such write is pending, bounded by the
same busy-defer + absolute 15 s cap machinery. Fully-resolved launches are
unaffected (the page-level guard already covers them).

0 files changed, 0 insertions, 0 deletions