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

* 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.

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

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