On 01/23/2014 01:04 AM, Laszlo Ersek wrote:
@@ -864,6 +884,16 @@ static int dump_init(DumpState *s, int fd, bool paging,
bool has_filter,
>
qemu_get_guest_simple_memory_mapping(&s->list,&s->guest_phys_blocks);
> }
>
> + s->nr_cpus = nr_cpus;
> + s->page_size = TARGET_PAGE_SIZE;
> + s->page_shift = ffs(s->page_size) - 1;
> +
> + get_max_mapnr(s);
Again from v6 10/11, good. The flag_flatten assignment has been dropped.
Initialization seems to happen in a good spot this time too.
> +
> + uint64_t tmp;
> + tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size);
> + s->len_dump_bitmap = tmp * s->page_size;
> +
> if (s->has_filter) {
> memory_mapping_filter(&s->list, s->begin, s->length);
> }
Again from v6 10/11.
These assignments now all occur without depending on a user request for
a compressed dump (kept this way in v7 12/13 too), but they are not
costly. The loop in get_max_mapnr() iterates over less than 10 mappings
in the non-paging dump case, and in the paging dump case it also
shouldn't be more than a hundred or so (as I recall from earlier
testing). This might be worth some regression-testing (perf-wise), but
it looks OK to me.
I see, moving them into "if(format...) {...}" block would be better. But, I
have no idea of "regression-testing (perf-wise)", would you mind give some hint?
--
Regards
Qiao Nuohan
