Re: [PATCH 2/3] scripts/sorttable: Build orc fast lookup table via sorttable tool

[changhuaixin <changhuaixin@linux.alibaba.com>]

> On Jul 24, 2020, at 9:53 PM, Ingo Molnar <mingo@kernel.org> wrote:
> 
> 
> * Huaixin Chang <changhuaixin@linux.alibaba.com> wrote:
> 
>> Since orc tables are already sorted by sorttable tool, let us move
>> building of fast lookup table into sorttable tool too. This saves us
>> 6380us from boot time under Intel(R) Xeon(R) CPU E5-2682 v4 @ 2.50GHz
>> with 64 cores.
> 
> Neat!
> 
>> +struct orc_sort_param {
>> +	size_t		lookup_table_size;
>> +	unsigned int	*orc_lookup_table;
>> +	unsigned long	start_ip;
>> +	size_t		text_size;
>> +	unsigned int	orc_num_entries;
>> +};
> 
>> 
>> +#define LOOKUP_BLOCK_ORDER	8
>> +#define LOOKUP_BLOCK_SIZE	(1 << LOOKUP_BLOCK_ORDER)
>> +
>> +	for (i = 0; i < lookup_num_blocks-1; i++) {
>> +		orc = __orc_find(g_orc_ip_table, g_orc_table,
>> +				 num_entries,
>> +				 lookup_start_ip + (LOOKUP_BLOCK_SIZE * i));
>> +		if (!orc) {
>> +			snprintf(g_err, ERRSTR_MAXSZ,
>> +					"Corrupt .orc_unwind table\n");
>> +			pthread_exit(g_err);
>> +		}
>> +
>> +		orc_lookup[i] = orc - g_orc_table;
>> +	}
>> +
>> +	/* Initialize the ending block: */
>> +	orc = __orc_find(g_orc_ip_table, g_orc_table, num_entries,
>> +			 lookup_stop_ip);
>> +	if (!orc) {
>> +		snprintf(g_err, ERRSTR_MAXSZ, "Corrupt .orc_unwind table\n");
>> +		pthread_exit(g_err);
>> +	}
>> +	orc_lookup[lookup_num_blocks-1] = orc - g_orc_table;
> 
> Yeah, so now this definition of LOOKUP_BLOCK_* basicaly duplicates the 
> arch/x86/include/asm/orc_lookup.h size, with no obvious link between 
> the two. This is asking for trouble.
> 
> <asm/orc_lookup.h> looks simple enough - can we include it in 
> scripts/sorttable.h?
> 
> Or better yet, please move these two defines into <asm/orc_types.h>, 
> which is already included in sorttable.h.
> 
Thanks!
Moving these two into <asm/orc_types.h> and capitalized spelling will be done in the following patches.

Huaixin

> BTW., please update your patches to spell 'ORC' in a capitalized 
> fashion, like most of the existing code does:
> 
>> 	/* create thread to sort ORC unwind tables concurrently */
> 
> Thanks,
> 
> 	Ingo