[Intel-gfx] [PATCH 04/10] drm/i915: move intel_context slab to direct module init/exit
Jason Ekstrand
jason at jlekstrand.net
Mon Jul 26 16:20:28 UTC 2021
On Mon, Jul 26, 2021 at 11:08 AM Tvrtko Ursulin
<tvrtko.ursulin at linux.intel.com> wrote:
> On 26/07/2021 16:42, Jason Ekstrand wrote:
> > On Mon, Jul 26, 2021 at 10:30 AM Jason Ekstrand <jason at jlekstrand.net> wrote:
> >>
> >> On Mon, Jul 26, 2021 at 3:35 AM Tvrtko Ursulin
> >> <tvrtko.ursulin at linux.intel.com> wrote:
> >>>
> >>>
> >>> On 23/07/2021 20:29, Daniel Vetter wrote:
> >>>> With the global kmem_cache shrink infrastructure gone there's nothing
> >>>> special and we can convert them over.
> >>>>
> >>>> I'm doing this split up into each patch because there's quite a bit of
> >>>> noise with removing the static global.slab_ce to just a
> >>>> slab_ce.
> >>>>
> >>>> Cc: Jason Ekstrand <jason at jlekstrand.net>
> >>>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> >>>> ---
> >>>> drivers/gpu/drm/i915/gt/intel_context.c | 25 ++++++++-----------------
> >>>> drivers/gpu/drm/i915/gt/intel_context.h | 3 +++
> >>>> drivers/gpu/drm/i915/i915_globals.c | 2 --
> >>>> drivers/gpu/drm/i915/i915_globals.h | 1 -
> >>>> drivers/gpu/drm/i915/i915_pci.c | 2 ++
> >>>> 5 files changed, 13 insertions(+), 20 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
> >>>> index baa05fddd690..283382549a6f 100644
> >>>> --- a/drivers/gpu/drm/i915/gt/intel_context.c
> >>>> +++ b/drivers/gpu/drm/i915/gt/intel_context.c
> >>>> @@ -7,7 +7,6 @@
> >>>> #include "gem/i915_gem_pm.h"
> >>>>
> >>>> #include "i915_drv.h"
> >>>> -#include "i915_globals.h"
> >>>> #include "i915_trace.h"
> >>>>
> >>>> #include "intel_context.h"
> >>>> @@ -15,14 +14,11 @@
> >>>> #include "intel_engine_pm.h"
> >>>> #include "intel_ring.h"
> >>>>
> >>>> -static struct i915_global_context {
> >>>> - struct i915_global base;
> >>>> - struct kmem_cache *slab_ce;
> >>>> -} global;
> >>>> +struct kmem_cache *slab_ce;
> >>
> >> Static? With that,
> >>
> >> Reviewed-by: Jason Ekstrand <jason at jlekstrand.net>
> >>
> >>>>
> >>>> static struct intel_context *intel_context_alloc(void)
> >>>> {
> >>>> - return kmem_cache_zalloc(global.slab_ce, GFP_KERNEL);
> >>>> + return kmem_cache_zalloc(slab_ce, GFP_KERNEL);
> >>>> }
> >>>>
> >>>> static void rcu_context_free(struct rcu_head *rcu)
> >>>> @@ -30,7 +26,7 @@ static void rcu_context_free(struct rcu_head *rcu)
> >>>> struct intel_context *ce = container_of(rcu, typeof(*ce), rcu);
> >>>>
> >>>> trace_intel_context_free(ce);
> >>>> - kmem_cache_free(global.slab_ce, ce);
> >>>> + kmem_cache_free(slab_ce, ce);
> >>>> }
> >>>>
> >>>> void intel_context_free(struct intel_context *ce)
> >>>> @@ -410,22 +406,17 @@ void intel_context_fini(struct intel_context *ce)
> >>>> i915_active_fini(&ce->active);
> >>>> }
> >>>>
> >>>> -static void i915_global_context_exit(void)
> >>>> +void i915_context_module_exit(void)
> >>>> {
> >>>> - kmem_cache_destroy(global.slab_ce);
> >>>> + kmem_cache_destroy(slab_ce);
> >>>> }
> >>>>
> >>>> -static struct i915_global_context global = { {
> >>>> - .exit = i915_global_context_exit,
> >>>> -} };
> >>>> -
> >>>> -int __init i915_global_context_init(void)
> >>>> +int __init i915_context_module_init(void)
> >>>> {
> >>>> - global.slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
> >>>> - if (!global.slab_ce)
> >>>> + slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
> >>>> + if (!slab_ce)
> >>>> return -ENOMEM;
> >>>>
> >>>> - i915_global_register(&global.base);
> >>>> return 0;
> >>>> }
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/gt/intel_context.h b/drivers/gpu/drm/i915/gt/intel_context.h
> >>>> index 974ef85320c2..a0ca82e3c40d 100644
> >>>> --- a/drivers/gpu/drm/i915/gt/intel_context.h
> >>>> +++ b/drivers/gpu/drm/i915/gt/intel_context.h
> >>>> @@ -30,6 +30,9 @@ void intel_context_init(struct intel_context *ce,
> >>>> struct intel_engine_cs *engine);
> >>>> void intel_context_fini(struct intel_context *ce);
> >>>>
> >>>> +void i915_context_module_exit(void);
> >>>> +int i915_context_module_init(void);
> >>>> +
> >>>> struct intel_context *
> >>>> intel_context_create(struct intel_engine_cs *engine);
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/i915_globals.c b/drivers/gpu/drm/i915/i915_globals.c
> >>>> index 3de7cf22ec76..d36eb7dc40aa 100644
> >>>> --- a/drivers/gpu/drm/i915/i915_globals.c
> >>>> +++ b/drivers/gpu/drm/i915/i915_globals.c
> >>>> @@ -7,7 +7,6 @@
> >>>> #include <linux/slab.h>
> >>>> #include <linux/workqueue.h>
> >>>>
> >>>> -#include "gem/i915_gem_context.h"
> >>>> #include "gem/i915_gem_object.h"
> >>>> #include "i915_globals.h"
> >>>> #include "i915_request.h"
> >>>> @@ -32,7 +31,6 @@ static void __i915_globals_cleanup(void)
> >>>> }
> >>>>
> >>>> static __initconst int (* const initfn[])(void) = {
> >>>> - i915_global_context_init,
> >>>> i915_global_gem_context_init,
> >>>> i915_global_objects_init,
> >>>> i915_global_request_init,
> >>>> diff --git a/drivers/gpu/drm/i915/i915_globals.h b/drivers/gpu/drm/i915/i915_globals.h
> >>>> index d80901ba75e3..60daa738a188 100644
> >>>> --- a/drivers/gpu/drm/i915/i915_globals.h
> >>>> +++ b/drivers/gpu/drm/i915/i915_globals.h
> >>>> @@ -23,7 +23,6 @@ int i915_globals_init(void);
> >>>> void i915_globals_exit(void);
> >>>>
> >>>> /* constructors */
> >>>> -int i915_global_context_init(void);
> >>>> int i915_global_gem_context_init(void);
> >>>> int i915_global_objects_init(void);
> >>>> int i915_global_request_init(void);
> >>>> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
> >>>> index f9527269e30a..266618157775 100644
> >>>> --- a/drivers/gpu/drm/i915/i915_pci.c
> >>>> +++ b/drivers/gpu/drm/i915/i915_pci.c
> >>>> @@ -33,6 +33,7 @@
> >>>> #include "i915_active.h"
> >>>> #include "i915_buddy.h"
> >>>> #include "i915_drv.h"
> >>>> +#include "gem/i915_gem_context.h"
> >>>
> >>> It's a bit ugly to go to a design where i915_pci.c has to include so
> >>> many random parts of i915. IMO for a complex driver like i915,
> >>> compartmentalizing so much knowledge about the internals was better
> >>> inside the globals layer.
> >>
> >> I agree that i915_pci feels like the wrong place to put this but I
> >> don't think that's so much because globals don't belong in i915_pci
> >> but because i915_init/exit don't belong there. Maybe, once this is
> >> all said and done (or at the start of the series), we should move
> >> i915_init/exit to i915_drv.c? Of course, there's a bunch of PCI
> >> probing stuff in i915_drv.c so..... yeah.... our organization is
> >> pretty busted.
> >
> > To put a finer point on this, the new "design" is really to have a
> > single flat list instead of two, one nested inside the other. There's
> > nothing wrong with that at all. The fact that all this stuff now
> > lives in i915_pci.c is ugly. But, as I said, that's kind-of an
> > accident of history because that's where i915_init() and i915_exit()
> > currently live. We should just move the lot to i915_drv.c.
>
> Hmm.. on one hand it does sounds better to move to i915_drv.c, but is it
> just because all these new include directive are so visibly out of place
> in i915_pci.c?
>
> Perhaps we need i915_module.c and then i915_globals is a completely fine
> concept. Desired IMO even since we have to avoid globals in general
> (multi-gpu) so it sticks out nicely that all that is allowed to be
> global has a special place.
>
> And i915_drv.c can remain being about a driver instance as bound to one GPU.
Is i915_drv.c about a single instance bound to a single GPU? If so,
then, yeah, maybe not the right place. Maybe a i915_module.c would be
better. It's all different shades of shed paint.
--Jason
> That feels like the best of both worlds to me.
>
> Regards,
>
> Tvrtko
>
> >
> >> --Jason
> >>
> >>> Maybe add a cover letter to explain the perceived pros and cons and
> >>> thinking in general?
> >>>
> >>> Regards,
> >>>
> >>> Tvrtko
> >>>
> >>>> #include "i915_perf.h"
> >>>> #include "i915_globals.h"
> >>>> #include "i915_selftest.h"
> >>>> @@ -1297,6 +1298,7 @@ static const struct {
> >>>> { i915_check_nomodeset, NULL },
> >>>> { i915_active_module_init, i915_active_module_exit },
> >>>> { i915_buddy_module_init, i915_buddy_module_exit },
> >>>> + { i915_context_module_init, i915_context_module_exit },
> >>>> { i915_globals_init, i915_globals_exit },
> >>>> { i915_mock_selftests, NULL },
> >>>> { i915_pmu_init, i915_pmu_exit },
> >>>>
> >>> _______________________________________________
> >>> Intel-gfx mailing list
> >>> Intel-gfx at lists.freedesktop.org
> >>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
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