When dealing with a working set larger than the GATT, or even the
mappable aperture when touching through the GTT, we end up with evicting
objects only to rebind them at a new offset again later. Moving an
object into and out of the GTT requires clflushing the pages, thus
causing a double-clflush penalty for rebinding.
To avoid having to clflush on rebinding, we can track the pages as they
are evicted from the GTT and only relinquish those pages on memory
pressure.
As usual, if it were not for the handling of out-of-memory condition and
having to manually shrink our own bo caches, it would be a net reduction
of code. Alas.
Note: The patch also contains a few changes to the last-hope
evict_everything logic in i916_gem_execbuffer.c - we no longer try to
only evict the purgeable stuff in a first try (since that's superflous
and only helps in OOM corner-cases, not fragmented-gtt trashing
situations).
Also, the extraction of the get_pages retry loop from bind_to_gtt (and
other callsites) to get_pages should imo have been a separate patch.
v2: Ditch the newly added put_pages (for unbound objects only) in
i915_gem_reset. A quick irc discussion hasn't revealed any important
reason for this, so if we need this, I'd like to have a git blame'able
explanation for it.
v3: Undo the s/drm_malloc_ab/kmalloc/ in get_pages that Chris noticed.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Split out code movements and rant a bit in the commit message
with a few Notes. Done v2]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The trace events adds whether or not the wait was blocking. Blocking in
this case means to hold struct_mutex (ie. no new work can be submitted
during the wait). The information is inherently racy.
The blocking information is racy since mutex_is_locked doesn't check
that the current thread holds the lock. The only other option would be
to pass the boolean information of whether or not the class was blocking
down through the stack which is less desirable.
v2: Don't do a trace event per loop. (Chris)
Only get blocking/non-blocking info (Chris)
v3: updated comment in code as well as commit msg (Daniel)
Add "(NB)" to trace information to remind us in 6 months (Ben)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Various issues involved with the space character were generating
warnings in the checkpatch.pl file. This patch removes most of those
warnings.
Signed-off-by: Akshay Joshi <me@akshayjoshi.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
A lot of minor tweaks to fix the tracepoints, improve the outputting for
ftrace, and to generally make the tracepoints useful again. It is a start
and enough to begin identifying performance issues and gaps in our
coverage.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
As the tracepoint is now decoupled from when the actual register is
assigned and was never complemented by detailing when the object lost
its fence, it has outlived its limited usefulness. Profiling the actual
stalls is a far more profitable venture anyway.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Add two tracepoints at I915_WRITE/READ for tracing down all the
register write and read.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This way we can make some more educated guesses as to why exactly
we can't use 2G apertures to their full potential ;)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Convert i915_gem_object_clflush to DEFINE_EVENT, and save ~0.5K:
text data bss dec hex filename
13204 2732 12 15948 3e4c i915_trace_points.o.orig
12668 2732 12 15412 3c34 i915_trace_points.o
No change in functionality.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes up include paths for i915_trace.h by setting additional CFLAGS
for i915_trace_points.c to include the $src directory. The required
TRACE_INCLUDE_PATH is then "."
Signed-off-by: Peter Clifton <pcjc2@cam.ac.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
If we trigger a tracepoint for batch buffer submission, it is a reasonable
assumption that we wish to also trace the batch buffer completion. So in
order to capture the completion events, we need to enable irqs... However,
we cannot rely on the completion event to disable the irq later, so we
defer the irq disable to the retire request.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
By adding tracepoint equivalents for WATCH_BUF/EXEC we are able to monitor
the lifetimes of objects, requests and significant events. These events can
then be probed using the tracing frameworks, such as systemtap and, in
particular, perf.
For example to record the stack trace for every GPU stall during a run, use
$ perf record -e i915:i915_gem_request_wait_begin -c 1 -g
And
$ perf report
to view the results.
[Updated to fix compilation issues caused.]
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ben Gamari <bgamari@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
