Sorry. I know I asked some questions last time around, but I am having trouble finding the response.
On Tue, May 05, 2015 at 09:53:55AM +0100, Chris Wilson wrote: > Convert the bo-cache into 2 phases: > > 1. A two second cache of recently used buffers, keep untouched. > 2. A two second cache of older buffers, marked for eviction. > > This helps reduce ioctl traffic on a rapid turnover in working sets. The > issue is that even a 2 second window is enough for an application to > fill all of memory with inactive buffers (and we would rely on the > oom-killer identifying the right culprit). > > Signed-off-by: Chris Wilson <[email protected]> > Cc: Daniel Vetter <[email protected]> > Cc: Ben Widawsky <[email protected]> > --- > intel/intel_bufmgr_gem.c | 27 ++++++++++++++++++++------- > 1 file changed, 20 insertions(+), 7 deletions(-) > > diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c > index 60c06fc..eeb9acf 100644 > --- a/intel/intel_bufmgr_gem.c > +++ b/intel/intel_bufmgr_gem.c > @@ -216,6 +216,11 @@ struct _drm_intel_bo_gem { > bool used_as_reloc_target; > > /** > + * Are we keeping this buffer around in semi-permenant cache? > + */ > + bool dontneed; > + > + /** > * Boolean of whether we have encountered an error whilst building the > relocation tree. > */ > bool has_error; > @@ -719,7 +724,8 @@ retry: > } > > if (alloc_from_cache) { > - if (!drm_intel_gem_bo_madvise_internal > + if (bo_gem->dontneed && > + !drm_intel_gem_bo_madvise_internal Why wouldn't you set dontneed = false? Just a thought, but it seems like a nicer solution here would just be a state variable tracking what we last sent with the madv ioctl. enum { WILLNEED DONTNEED } With that, it might be cool for the curious to put a histogram/hysteresis thing. Every time you hit this condition to see how many times we flip flop. > (bufmgr_gem, bo_gem, I915_MADV_WILLNEED)) { > drm_intel_gem_bo_free(&bo_gem->bo); > drm_intel_gem_bo_cache_purge_bucket(bufmgr_gem, > @@ -1166,19 +1172,28 @@ drm_intel_gem_cleanup_bo_cache(drm_intel_bufmgr_gem > *bufmgr_gem, time_t time) > for (i = 0; i < bufmgr_gem->num_buckets; i++) { > struct drm_intel_gem_bo_bucket *bucket = > &bufmgr_gem->cache_bucket[i]; > + drmMMListHead madv; > > + DRMINITLISTHEAD(&madv); > while (!DRMLISTEMPTY(&bucket->head)) { > drm_intel_bo_gem *bo_gem; > > bo_gem = DRMLISTENTRY(drm_intel_bo_gem, > bucket->head.next, head); > - if (time - bo_gem->free_time <= 1) > + if (time - bo_gem->free_time < 2*(1+bo_gem->dontneed)) > break; > > DRMLISTDEL(&bo_gem->head); > - > - drm_intel_gem_bo_free(&bo_gem->bo); > + if (bo_gem->dontneed) { > + drm_intel_gem_bo_free(&bo_gem->bo); > + } else { > + drm_intel_gem_bo_madvise_internal(bufmgr_gem, > bo_gem, > + > I915_MADV_DONTNEED); > + bo_gem->dontneed = 1; > + DRMLISTADDTAIL(&bo_gem->head, &madv); > + } > } Again with above, how about? assert(!bo_gem->dontneed); bo_gem->dontneed = true; Also I think some comments here explaining what you're doing overall would bce nice since I surely won't remember it in >= 1 minutes. > + DRMLISTJOIN(&madv, &bucket->head); > } > > bufmgr_gem->time = time; > @@ -1289,9 +1304,7 @@ drm_intel_gem_bo_unreference_final(drm_intel_bo *bo, > time_t time) > > bucket = drm_intel_gem_bo_bucket_for_size(bufmgr_gem, bo->size); > /* Put the buffer into our internal cache for reuse if we can. */ > - if (bufmgr_gem->bo_reuse && bo_gem->reusable && bucket != NULL && > - drm_intel_gem_bo_madvise_internal(bufmgr_gem, bo_gem, > - I915_MADV_DONTNEED)) { > + if (bufmgr_gem->bo_reuse && bo_gem->reusable && bucket != NULL) { > bo_gem->free_time = time; > > bo_gem->name = NULL; Just to be clear, you're reducing IOCTL traffic by deferring an IOCTL until you cleanup the BO cache. I think I said it last time, overall the idea seems fine to me. -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
