From: Cliff Wickman <[email protected]> Because addresses of each successive page structure are often descending it is much faster to use read()'s, so set off info->flag_usemmap while doing exclude_free_page().
Signed-off-by: Cliff Wickman <[email protected]> --- makedumpfile.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) Index: makedumpfile.mmap/makedumpfile.c =================================================================== --- makedumpfile.mmap.orig/makedumpfile.c +++ makedumpfile.mmap/makedumpfile.c @@ -3925,9 +3925,18 @@ _exclude_free_page(void) return TRUE; } +/* + * Note that this is a very lengthy process, even using mmap(2). The + * page structures in the free lists are read one-at-a-time, but using + * readpage_elf(), which reads an entire page. And addresses of each + * successive page structure are often descending, which means that each + * read is another mmap(2) operation. + * It is much faster to use read()'s, so set off info->flag_usemmap here. + */ int exclude_free_page(void) { + int save = info->flag_usemmap; /* * Check having necessary information. */ @@ -3961,8 +3970,12 @@ exclude_free_page(void) /* * Detect free pages and update 2nd-bitmap. */ - if (!_exclude_free_page()) + info->flag_usemmap = 0; + if (!_exclude_free_page()) { + info->flag_usemmap = save; return FALSE; + } + info->flag_usemmap = save; return TRUE; } _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
