On Tue, Apr 02, 2019 at 11:14:40AM -0400, Mathieu Desnoyers wrote: > ----- On Apr 2, 2019, at 10:28 AM, paulmck paulmck@xxxxxxxxxxxxx wrote: > > > Hello! > > > > This series prohibits use of DEFINE_SRCU() and DEFINE_STATIC_SRCU() > > by loadable modules. The reason for this prohibition is the fact > > that using these two macros within modules requires that the size of > > the reserved region be increased, which is not something we want to > > be doing all that often. Instead, loadable modules should define an > > srcu_struct and invoke init_srcu_struct() from their module_init function > > and cleanup_srcu_struct() from their module_exit function. Note that > > modules using call_srcu() will also need to invoke srcu_barrier() from > > their module_exit function. > > This arbitrary API limitation seems weird. > > Isn't there a way to allow modules to use DEFINE_SRCU and DEFINE_STATIC_SRCU > while implementing them with dynamic allocation under the hood ? Although call_srcu() already has initialization hooks, some would also be required in srcu_read_lock(), and I am concerned about adding memory allocation at that point, especially given the possibility of memory-allocation failure. And the possibility that the first srcu_read_lock() happens in an interrupt handler or similar. Or am I missing a trick here? Thanx, Paul > Thanks, > > Mathieu > > > > > > This series consist of the following: > > > > 1. Dynamically allocate dax_srcu. > > > > 2. Dynamically allocate drm_unplug_srcu. > > > > 3. Dynamically allocate kfd_processes_srcu. > > > > These build and have been subjected to 0day testing, but might also need > > testing by someone having the requisite hardware. > > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > drivers/dax/super.c | 10 +++++- > > drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 5 +++ > > drivers/gpu/drm/amd/amdkfd/kfd_process.c | 2 - > > drivers/gpu/drm/drm_drv.c | 8 ++++ > > include/linux/srcutree.h | 19 +++++++++-- > > kernel/rcu/rcuperf.c | 40 +++++++++++++++++++----- > > kernel/rcu/rcutorture.c | 48 +++++++++++++++++++++-------- > > 7 files changed, 105 insertions(+), 27 deletions(-) > > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com > _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
