From e0b9f3e4d81793d967d75233bc340cd3a0b0d250 Mon Sep 17 00:00:00 2001 From: glebius Date: Wed, 24 Jul 2013 06:13:00 +0000 Subject: Since r251709 a slab no longer use 8-bit indicies to manage items, thus remove a stale comment. Reviewed by: jeff --- sys/vm/uma_int.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'sys/vm/uma_int.h') diff --git a/sys/vm/uma_int.h b/sys/vm/uma_int.h index 8d46c91..9aa0560 100644 --- a/sys/vm/uma_int.h +++ b/sys/vm/uma_int.h @@ -49,14 +49,6 @@ * 10% memory waste we potentially allocate a separate uma_slab_t if this will * improve the number of items per slab that will fit. * - * Other potential space optimizations are storing the 8bit of linkage in space - * wasted between items due to alignment problems. This may yield a much better - * memory footprint for certain sizes of objects. Another alternative is to - * increase the UMA_SLAB_SIZE, or allow for dynamic slab sizes. I prefer - * dynamic slab sizes because we could stick with 8 bit indices and only use - * large slab sizes for zones with a lot of waste per slab. This may create - * inefficiencies in the vm subsystem due to fragmentation in the address space. - * * The only really gross cases, with regards to memory waste, are for those * items that are just over half the page size. You can get nearly 50% waste, * so you fall back to the memory footprint of the power of two allocator. I -- cgit v1.1