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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

January 2017 Kernel Hackers Manual 4.8.