IDR_PRELOAD(9)                    Basic Kernel Library Functions                   IDR_PRELOAD(9)



NAME
       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;

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                            IDR_PRELOAD(9)