idr_preload (9) Linux Manual Page
idr_preload – preload for idr_alloc
Synopsis
void idr_preload(gfp_t gfp_mask);Arguments
gfp_mask
-
- allocation mask to use for preloading
Description
Preload per-cpu layer buffer for idr_alloc. Can only be used from process context and each idr_preload invocation should be matched with idr_preload_end. Note that preemption is disabled while preloaded. The first idr_alloc in the preloaded section can be treated as if it were invoked with gfp_mask used for preloading. This allows using more permissive allocation masks for idrs protected by spinlocks. For example, if idr_alloc below fails, the failure can be treated as if idr_alloc were called with GFP_KERNEL rather than GFP_NOWAIT. idr_preload(GFP_KERNEL); spin_lock(lock);
id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT);
spin_unlock(lock);
idr_preload_end;
if (id < 0)
error;