Re: slab redzoning

[Manfred Spraul]

William Lee Irwin III wrote:

> -if ((size < 4096 || fls(size-1) == fls(size-1+3*BYTES_PER_WORD)))
> +if (size + 3*BYTES_PER_WORD <= PAGE_SIZE ||
I understand this change: objects between 4082 and 4095 bytes are 
redzoned and cause order==1 allocations, that's wrong.

> +			((size & (size - 1)) &&
> +			(1 << fls(size)) - size > 3*BYTES_PER_WORD))
Why this change? I've tested my fls(size-1)==fls(size-1-3*4) approach 
and it always returned the right result: No redzoning between 8181 and 
8192 bytes, between 16373 and 16384, etc.

--
   Manfred

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