| Message ID | 20190402105006.48f93e53@canb.auug.org.au (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | linux-next: build failure after merge of the drm-misc tree | expand |
Thanks, patch is: Reviewed-by: Qiang Yu <yuq825@gmail.com> Regards, Qiang On Tue, Apr 2, 2019 at 7:50 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote: > > Hi all, > > After merging the drm-misc tree, today's linux-next build (x86_64 > allmodconfig) failed like this: > > In file included from include/linux/kernel.h:7, > from include/asm-generic/bug.h:18, > from arch/x86/include/asm/bug.h:83, > from include/linux/bug.h:5, > from include/linux/mmdebug.h:5, > from include/linux/gfp.h:5, > from include/linux/slab.h:15, > from drivers/gpu/drm/lima/lima_ctx.c:4: > drivers/gpu/drm/lima/lima_ctx.c: In function 'lima_ctx_create': > include/linux/limits.h:13:18: warning: passing argument 3 of 'xa_alloc' makes pointer from integer without a cast [-Wint-conversion] > #define UINT_MAX (~0U) > ^~~~~ > drivers/gpu/drm/lima/lima_ctx.c:26:36: note: in expansion of macro 'UINT_MAX' > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > ^~~~~~~~ > In file included from include/linux/radix-tree.h:31, > from include/linux/idr.h:15, > from include/drm/drm_device.h:7, > from drivers/gpu/drm/lima/lima_device.h:7, > from drivers/gpu/drm/lima/lima_ctx.c:6: > include/linux/xarray.h:817:9: note: expected 'void *' but argument is of type 'unsigned int' > void *entry, struct xa_limit limit, gfp_t gfp) > ~~~~~~^~~~~ > drivers/gpu/drm/lima/lima_ctx.c:26:46: error: incompatible type for argument 4 of 'xa_alloc' > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > ^~~ > In file included from include/linux/radix-tree.h:31, > from include/linux/idr.h:15, > from include/drm/drm_device.h:7, > from drivers/gpu/drm/lima/lima_device.h:7, > from drivers/gpu/drm/lima/lima_ctx.c:6: > include/linux/xarray.h:817:32: note: expected 'struct xa_limit' but argument is of type 'struct lima_ctx *' > void *entry, struct xa_limit limit, gfp_t gfp) > ~~~~~~~~~~~~~~~~^~~~~ > > Caused by commit > > a1d2a6339961 ("drm/lima: driver for ARM Mali4xx GPUs") > > interacting with commit > > a3e4d3f97ec8 ("XArray: Redesign xa_alloc API") > > from Linus' tree (v5.1-rc1). > > I have applied the following patch for today. It could be applied as > part of a merge of v5.1-rc1 into drm-misc. > > From: Stephen Rothwell <sfr@canb.auug.org.au> > Date: Tue, 2 Apr 2019 10:45:32 +1100 > Subject: [PATCH] drm/lima: update for xa_alloc API change > > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> > --- > drivers/gpu/drm/lima/lima_ctx.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ctx.c > index c8d12f7c6894..bafa00d74cc5 100644 > --- a/drivers/gpu/drm/lima/lima_ctx.c > +++ b/drivers/gpu/drm/lima/lima_ctx.c > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > goto err_out0; > } > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > if (err < 0) > goto err_out0; > > -- > 2.20.1 > > -- > Cheers, > Stephen Rothwell
On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > Thanks, patch is: > Reviewed-by: Qiang Yu <yuq825@gmail.com> Good time to get started with committing patches? In general it's kinda confusing if the maintainer r-bs a patch, but doesn't say whether/when/how it gets merged. Big chance the patch will get lost in limbo and fall through cracks. -Daniel > > Regards, > Qiang > > On Tue, Apr 2, 2019 at 7:50 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote: > > > > Hi all, > > > > After merging the drm-misc tree, today's linux-next build (x86_64 > > allmodconfig) failed like this: > > > > In file included from include/linux/kernel.h:7, > > from include/asm-generic/bug.h:18, > > from arch/x86/include/asm/bug.h:83, > > from include/linux/bug.h:5, > > from include/linux/mmdebug.h:5, > > from include/linux/gfp.h:5, > > from include/linux/slab.h:15, > > from drivers/gpu/drm/lima/lima_ctx.c:4: > > drivers/gpu/drm/lima/lima_ctx.c: In function 'lima_ctx_create': > > include/linux/limits.h:13:18: warning: passing argument 3 of 'xa_alloc' makes pointer from integer without a cast [-Wint-conversion] > > #define UINT_MAX (~0U) > > ^~~~~ > > drivers/gpu/drm/lima/lima_ctx.c:26:36: note: in expansion of macro 'UINT_MAX' > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > ^~~~~~~~ > > In file included from include/linux/radix-tree.h:31, > > from include/linux/idr.h:15, > > from include/drm/drm_device.h:7, > > from drivers/gpu/drm/lima/lima_device.h:7, > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > include/linux/xarray.h:817:9: note: expected 'void *' but argument is of type 'unsigned int' > > void *entry, struct xa_limit limit, gfp_t gfp) > > ~~~~~~^~~~~ > > drivers/gpu/drm/lima/lima_ctx.c:26:46: error: incompatible type for argument 4 of 'xa_alloc' > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > ^~~ > > In file included from include/linux/radix-tree.h:31, > > from include/linux/idr.h:15, > > from include/drm/drm_device.h:7, > > from drivers/gpu/drm/lima/lima_device.h:7, > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > include/linux/xarray.h:817:32: note: expected 'struct xa_limit' but argument is of type 'struct lima_ctx *' > > void *entry, struct xa_limit limit, gfp_t gfp) > > ~~~~~~~~~~~~~~~~^~~~~ > > > > Caused by commit > > > > a1d2a6339961 ("drm/lima: driver for ARM Mali4xx GPUs") > > > > interacting with commit > > > > a3e4d3f97ec8 ("XArray: Redesign xa_alloc API") > > > > from Linus' tree (v5.1-rc1). > > > > I have applied the following patch for today. It could be applied as > > part of a merge of v5.1-rc1 into drm-misc. > > > > From: Stephen Rothwell <sfr@canb.auug.org.au> > > Date: Tue, 2 Apr 2019 10:45:32 +1100 > > Subject: [PATCH] drm/lima: update for xa_alloc API change > > > > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> > > --- > > drivers/gpu/drm/lima/lima_ctx.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ctx.c > > index c8d12f7c6894..bafa00d74cc5 100644 > > --- a/drivers/gpu/drm/lima/lima_ctx.c > > +++ b/drivers/gpu/drm/lima/lima_ctx.c > > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > > goto err_out0; > > } > > > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > > if (err < 0) > > goto err_out0; > > > > -- > > 2.20.1 > > > > -- > > Cheers, > > Stephen Rothwell
On Tue, Apr 2, 2019 at 3:57 PM Daniel Vetter <daniel@ffwll.ch> wrote: > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > Thanks, patch is: > > Reviewed-by: Qiang Yu <yuq825@gmail.com> > > Good time to get started with committing patches? In general it's kinda > confusing if the maintainer r-bs a patch, but doesn't say whether/when/how > it gets merged. Big chance the patch will get lost in limbo and fall > through cracks. Thanks for the remind, this patch should only be applied to drm-misc-next branch when 5.1-rcx branch gets merged to drm-misc-next for the new xa_alloc API. So I expect the guy who do the 5.1-rcx merge should apply this patch. Who will do the merge? Regards, Qiang > > > > > Regards, > > Qiang > > > > On Tue, Apr 2, 2019 at 7:50 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote: > > > > > > Hi all, > > > > > > After merging the drm-misc tree, today's linux-next build (x86_64 > > > allmodconfig) failed like this: > > > > > > In file included from include/linux/kernel.h:7, > > > from include/asm-generic/bug.h:18, > > > from arch/x86/include/asm/bug.h:83, > > > from include/linux/bug.h:5, > > > from include/linux/mmdebug.h:5, > > > from include/linux/gfp.h:5, > > > from include/linux/slab.h:15, > > > from drivers/gpu/drm/lima/lima_ctx.c:4: > > > drivers/gpu/drm/lima/lima_ctx.c: In function 'lima_ctx_create': > > > include/linux/limits.h:13:18: warning: passing argument 3 of 'xa_alloc' makes pointer from integer without a cast [-Wint-conversion] > > > #define UINT_MAX (~0U) > > > ^~~~~ > > > drivers/gpu/drm/lima/lima_ctx.c:26:36: note: in expansion of macro 'UINT_MAX' > > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > ^~~~~~~~ > > > In file included from include/linux/radix-tree.h:31, > > > from include/linux/idr.h:15, > > > from include/drm/drm_device.h:7, > > > from drivers/gpu/drm/lima/lima_device.h:7, > > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > > include/linux/xarray.h:817:9: note: expected 'void *' but argument is of type 'unsigned int' > > > void *entry, struct xa_limit limit, gfp_t gfp) > > > ~~~~~~^~~~~ > > > drivers/gpu/drm/lima/lima_ctx.c:26:46: error: incompatible type for argument 4 of 'xa_alloc' > > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > ^~~ > > > In file included from include/linux/radix-tree.h:31, > > > from include/linux/idr.h:15, > > > from include/drm/drm_device.h:7, > > > from drivers/gpu/drm/lima/lima_device.h:7, > > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > > include/linux/xarray.h:817:32: note: expected 'struct xa_limit' but argument is of type 'struct lima_ctx *' > > > void *entry, struct xa_limit limit, gfp_t gfp) > > > ~~~~~~~~~~~~~~~~^~~~~ > > > > > > Caused by commit > > > > > > a1d2a6339961 ("drm/lima: driver for ARM Mali4xx GPUs") > > > > > > interacting with commit > > > > > > a3e4d3f97ec8 ("XArray: Redesign xa_alloc API") > > > > > > from Linus' tree (v5.1-rc1). > > > > > > I have applied the following patch for today. It could be applied as > > > part of a merge of v5.1-rc1 into drm-misc. > > > > > > From: Stephen Rothwell <sfr@canb.auug.org.au> > > > Date: Tue, 2 Apr 2019 10:45:32 +1100 > > > Subject: [PATCH] drm/lima: update for xa_alloc API change > > > > > > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> > > > --- > > > drivers/gpu/drm/lima/lima_ctx.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ctx.c > > > index c8d12f7c6894..bafa00d74cc5 100644 > > > --- a/drivers/gpu/drm/lima/lima_ctx.c > > > +++ b/drivers/gpu/drm/lima/lima_ctx.c > > > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > > > goto err_out0; > > > } > > > > > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > > > if (err < 0) > > > goto err_out0; > > > > > > -- > > > 2.20.1 > > > > > > -- > > > Cheers, > > > Stephen Rothwell > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch
On Tue, Apr 02, 2019 at 04:59:37PM +0800, Qiang Yu wrote: > On Tue, Apr 2, 2019 at 3:57 PM Daniel Vetter <daniel@ffwll.ch> wrote: > > > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > > Thanks, patch is: > > > Reviewed-by: Qiang Yu <yuq825@gmail.com> > > > > Good time to get started with committing patches? In general it's kinda > > confusing if the maintainer r-bs a patch, but doesn't say whether/when/how > > it gets merged. Big chance the patch will get lost in limbo and fall > > through cracks. > > Thanks for the remind, this patch should only be applied to drm-misc-next > branch when 5.1-rcx branch gets merged to drm-misc-next for the new > xa_alloc API. So I expect the guy who do the 5.1-rcx merge should apply > this patch. Who will do the merge? Oh right, I was kinda not yet awake :-) Yeah Dave/me and drm-misc maintainers will resolve this when drm-misc lands in drm-next. Might then need a backmerge in drm-misc to roll forward. -Daniel > > Regards, > Qiang > > > > > > > > > Regards, > > > Qiang > > > > > > On Tue, Apr 2, 2019 at 7:50 AM Stephen Rothwell <sfr@canb.auug.org.au> wrote: > > > > > > > > Hi all, > > > > > > > > After merging the drm-misc tree, today's linux-next build (x86_64 > > > > allmodconfig) failed like this: > > > > > > > > In file included from include/linux/kernel.h:7, > > > > from include/asm-generic/bug.h:18, > > > > from arch/x86/include/asm/bug.h:83, > > > > from include/linux/bug.h:5, > > > > from include/linux/mmdebug.h:5, > > > > from include/linux/gfp.h:5, > > > > from include/linux/slab.h:15, > > > > from drivers/gpu/drm/lima/lima_ctx.c:4: > > > > drivers/gpu/drm/lima/lima_ctx.c: In function 'lima_ctx_create': > > > > include/linux/limits.h:13:18: warning: passing argument 3 of 'xa_alloc' makes pointer from integer without a cast [-Wint-conversion] > > > > #define UINT_MAX (~0U) > > > > ^~~~~ > > > > drivers/gpu/drm/lima/lima_ctx.c:26:36: note: in expansion of macro 'UINT_MAX' > > > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > > ^~~~~~~~ > > > > In file included from include/linux/radix-tree.h:31, > > > > from include/linux/idr.h:15, > > > > from include/drm/drm_device.h:7, > > > > from drivers/gpu/drm/lima/lima_device.h:7, > > > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > > > include/linux/xarray.h:817:9: note: expected 'void *' but argument is of type 'unsigned int' > > > > void *entry, struct xa_limit limit, gfp_t gfp) > > > > ~~~~~~^~~~~ > > > > drivers/gpu/drm/lima/lima_ctx.c:26:46: error: incompatible type for argument 4 of 'xa_alloc' > > > > err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > > ^~~ > > > > In file included from include/linux/radix-tree.h:31, > > > > from include/linux/idr.h:15, > > > > from include/drm/drm_device.h:7, > > > > from drivers/gpu/drm/lima/lima_device.h:7, > > > > from drivers/gpu/drm/lima/lima_ctx.c:6: > > > > include/linux/xarray.h:817:32: note: expected 'struct xa_limit' but argument is of type 'struct lima_ctx *' > > > > void *entry, struct xa_limit limit, gfp_t gfp) > > > > ~~~~~~~~~~~~~~~~^~~~~ > > > > > > > > Caused by commit > > > > > > > > a1d2a6339961 ("drm/lima: driver for ARM Mali4xx GPUs") > > > > > > > > interacting with commit > > > > > > > > a3e4d3f97ec8 ("XArray: Redesign xa_alloc API") > > > > > > > > from Linus' tree (v5.1-rc1). > > > > > > > > I have applied the following patch for today. It could be applied as > > > > part of a merge of v5.1-rc1 into drm-misc. > > > > > > > > From: Stephen Rothwell <sfr@canb.auug.org.au> > > > > Date: Tue, 2 Apr 2019 10:45:32 +1100 > > > > Subject: [PATCH] drm/lima: update for xa_alloc API change > > > > > > > > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> > > > > --- > > > > drivers/gpu/drm/lima/lima_ctx.c | 2 +- > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ctx.c > > > > index c8d12f7c6894..bafa00d74cc5 100644 > > > > --- a/drivers/gpu/drm/lima/lima_ctx.c > > > > +++ b/drivers/gpu/drm/lima/lima_ctx.c > > > > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > > > > goto err_out0; > > > > } > > > > > > > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > > > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > > > > if (err < 0) > > > > goto err_out0; > > > > > > > > -- > > > > 2.20.1 > > > > > > > > -- > > > > Cheers, > > > > Stephen Rothwell > > > > -- > > Daniel Vetter > > Software Engineer, Intel Corporation > > http://blog.ffwll.ch
On Tue, Apr 02, 2019 at 10:50:06AM +1100, Stephen Rothwell wrote: > +++ b/drivers/gpu/drm/lima/lima_ctx.c > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > goto err_out0; > } > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > if (err < 0) > goto err_out0; I agree that this is an exact translation of what the code was doing, but I don't think it's what the author intended the code to do. They almost certainly meant: err = xa_alloc(&mgr->handles, id, ctx, xa_limit_32b, GFP_KERNEL); I'm basing this on: +struct drm_lima_ctx_create { + __u32 id; /* out, context handle */ + __u32 _pad; /* pad, must be zero */ +}; (and this confusion is exactly why I changed the API ...)
On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > Thanks, patch is: > Reviewed-by: Qiang Yu <yuq825@gmail.com> This looks like a fairly naive conversion from the old IDR API to the XArray API. You should be able to remove mgr->lock entirely, relying on the xa_lock for synchronising free and get. If you think it's worth it, you could even use kfree_rcu() to free the ctx and kref_get_unless_zero() and then your get path would be lock-free.
On Tue, Apr 2, 2019 at 7:21 PM Matthew Wilcox <willy@infradead.org> wrote: > > On Tue, Apr 02, 2019 at 10:50:06AM +1100, Stephen Rothwell wrote: > > +++ b/drivers/gpu/drm/lima/lima_ctx.c > > @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) > > goto err_out0; > > } > > > > - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); > > + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); > > if (err < 0) > > goto err_out0; > > I agree that this is an exact translation of what the code was doing, > but I don't think it's what the author intended the code to do. > They almost certainly meant: > > err = xa_alloc(&mgr->handles, id, ctx, xa_limit_32b, GFP_KERNEL); > > I'm basing this on: > > +struct drm_lima_ctx_create { > + __u32 id; /* out, context handle */ > + __u32 _pad; /* pad, must be zero */ > +}; > > (and this confusion is exactly why I changed the API ...) Right, I plan to send out a patch like yours after drm-misc-next merge 5.1 changes, as this is a build fix patch and already applied to somewhere. I can send out another patch now if merge guys could use the new one directly.
On Tue, Apr 2, 2019 at 7:26 PM Matthew Wilcox <willy@infradead.org> wrote: > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > Thanks, patch is: > > Reviewed-by: Qiang Yu <yuq825@gmail.com> > > This looks like a fairly naive conversion from the old IDR API to the > XArray API. You should be able to remove mgr->lock entirely, relying on > the xa_lock for synchronising free and get. I'm afraid the a little complex free path may involve some might sleep functions so use a mutex lock instead of spinlock. > If you think it's worth it, > you could even use kfree_rcu() to free the ctx and kref_get_unless_zero() > and then your get path would be lock-free. I can take a look this way, thanks.
On Tue, Apr 02, 2019 at 09:56:08PM +0800, Qiang Yu wrote: > On Tue, Apr 2, 2019 at 7:26 PM Matthew Wilcox <willy@infradead.org> wrote: > > > > On Tue, Apr 02, 2019 at 01:55:03PM +0800, Qiang Yu wrote: > > > Thanks, patch is: > > > Reviewed-by: Qiang Yu <yuq825@gmail.com> > > > > This looks like a fairly naive conversion from the old IDR API to the > > XArray API. You should be able to remove mgr->lock entirely, relying on > > the xa_lock for synchronising free and get. > > I'm afraid the a little complex free path may involve some might sleep > functions so use a mutex lock instead of spinlock. Ah, good call ... + mutex_lock(&mgr->lock); + ctx = xa_erase(&mgr->handles, id); + if (ctx) + kref_put(&ctx->refcnt, lima_ctx_do_release); + else + ret = -EINVAL; + mutex_unlock(&mgr->lock); +static void lima_ctx_do_release(struct kref *ref) +{ + struct lima_ctx *ctx = container_of(ref, struct lima_ctx, refcnt); + int i; + + for (i = 0; i < lima_pipe_num; i++) + lima_sched_context_fini(ctx->dev->pipe + i, ctx->context + i); + kfree(ctx); +} +void lima_sched_context_fini(struct lima_sched_pipe *pipe, + struct lima_sched_context *context) +{ + drm_sched_entity_fini(&context->base); +} and drm_sched_entity_fini() can call kthread_park(), which does sleep. > > If you think it's worth it, > > you could even use kfree_rcu() to free the ctx and kref_get_unless_zero() > > and then your get path would be lock-free. > > I can take a look this way, thanks. I think that's the only way you can get rid of the mutex, given the sleeping functions called in the free path.
diff --git a/drivers/gpu/drm/lima/lima_ctx.c b/drivers/gpu/drm/lima/lima_ctx.c index c8d12f7c6894..bafa00d74cc5 100644 --- a/drivers/gpu/drm/lima/lima_ctx.c +++ b/drivers/gpu/drm/lima/lima_ctx.c @@ -23,7 +23,7 @@ int lima_ctx_create(struct lima_device *dev, struct lima_ctx_mgr *mgr, u32 *id) goto err_out0; } - err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); + err = xa_alloc(&mgr->handles, id, ctx, XA_LIMIT(*id, UINT_MAX), GFP_KERNEL); if (err < 0) goto err_out0;
Hi all, After merging the drm-misc tree, today's linux-next build (x86_64 allmodconfig) failed like this: In file included from include/linux/kernel.h:7, from include/asm-generic/bug.h:18, from arch/x86/include/asm/bug.h:83, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/gpu/drm/lima/lima_ctx.c:4: drivers/gpu/drm/lima/lima_ctx.c: In function 'lima_ctx_create': include/linux/limits.h:13:18: warning: passing argument 3 of 'xa_alloc' makes pointer from integer without a cast [-Wint-conversion] #define UINT_MAX (~0U) ^~~~~ drivers/gpu/drm/lima/lima_ctx.c:26:36: note: in expansion of macro 'UINT_MAX' err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); ^~~~~~~~ In file included from include/linux/radix-tree.h:31, from include/linux/idr.h:15, from include/drm/drm_device.h:7, from drivers/gpu/drm/lima/lima_device.h:7, from drivers/gpu/drm/lima/lima_ctx.c:6: include/linux/xarray.h:817:9: note: expected 'void *' but argument is of type 'unsigned int' void *entry, struct xa_limit limit, gfp_t gfp) ~~~~~~^~~~~ drivers/gpu/drm/lima/lima_ctx.c:26:46: error: incompatible type for argument 4 of 'xa_alloc' err = xa_alloc(&mgr->handles, id, UINT_MAX, ctx, GFP_KERNEL); ^~~ In file included from include/linux/radix-tree.h:31, from include/linux/idr.h:15, from include/drm/drm_device.h:7, from drivers/gpu/drm/lima/lima_device.h:7, from drivers/gpu/drm/lima/lima_ctx.c:6: include/linux/xarray.h:817:32: note: expected 'struct xa_limit' but argument is of type 'struct lima_ctx *' void *entry, struct xa_limit limit, gfp_t gfp) ~~~~~~~~~~~~~~~~^~~~~ Caused by commit a1d2a6339961 ("drm/lima: driver for ARM Mali4xx GPUs") interacting with commit a3e4d3f97ec8 ("XArray: Redesign xa_alloc API") from Linus' tree (v5.1-rc1). I have applied the following patch for today. It could be applied as part of a merge of v5.1-rc1 into drm-misc. From: Stephen Rothwell <sfr@canb.auug.org.au> Date: Tue, 2 Apr 2019 10:45:32 +1100 Subject: [PATCH] drm/lima: update for xa_alloc API change Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> --- drivers/gpu/drm/lima/lima_ctx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)