linux-kernel - Re: [PATCH UPDATED 09/10] percpu: implement new dynamic percpu allocator

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20090220003743.d787107b.akpm@linux-foundation.org>
Date:	Fri, 20 Feb 2009 00:37:43 -0800
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Tejun Heo <tj@...nel.org>
Cc:	rusty@...tcorp.com.au, tglx@...utronix.de, x86@...nel.org,
	linux-kernel@...r.kernel.org, hpa@...or.com, jeremy@...p.org,
	cpw@....com, mingo@...e.hu
Subject: Re: [PATCH UPDATED 09/10] percpu: implement new dynamic percpu
 allocator

On Fri, 20 Feb 2009 16:30:01 +0900 Tejun Heo <tj@...nel.org> wrote:

> Impact: new scalable dynamic percpu allocator which allows dynamic
>         percpu areas to be accessed the same way as static ones
> 
> Implement scalable dynamic percpu allocator which can be used for both
> static and dynamic percpu areas.  This will allow static and dynamic
> areas to share faster direct access methods.  This feature is optional
> and enabled only when CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is defined by
> arch.  Please read comment on top of mm/percpu.c for details.
> 
> ...
>
> +static int pcpu_unit_pages_shift;
> +static int pcpu_unit_pages;
> +static int pcpu_unit_shift;
> +static int pcpu_unit_size;
> +static int pcpu_chunk_size;
> +static int pcpu_nr_slots;
> +static size_t pcpu_chunk_struct_size;
> +
> +/* the address of the first chunk which starts with the kernel static area */
> +void *pcpu_base_addr;
> +EXPORT_SYMBOL_GPL(pcpu_base_addr);
> +
> +/* the size of kernel static area */
> +static int pcpu_static_size;

It would be nice to document the units of the `size' variables.  Bytes?
Pages?

Or, better: s/size/bytes/g.  

> +static int pcpu_size_to_slot(int size)
> +{
> +	int highbit = fls(size);
> +	return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1);
> +}

See,

static int pcpu_bytes_to_slot(int bytes)
{
	int highbit = fls(bytes);
	return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1);
}

is clearer.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/