On Thu 2015-03-19 17:28:58, Tom(JeHyeon) Yeon wrote: > From: "Tom(JeHyeon) Yeon" <[email protected]> > > I tested the performance of swsusp_free operation. > The free time took about 58768us before commit fdd64ed, and > the free time took about 40535us after the commit fdd64ed. > > But, I optimized the function before I saw commit fdd64ed. > So, I applied the patch in my system.(ARM Coretex A9, Dual Core 1GHz) > The free time took about 35164us. > I think that the finding routine for the same pfn is redundant > > Signed-off-by: Tom(JeHyeon) Yeon <[email protected]>
Well, saving 5msec on operation that takes 30 seconds is not that much, but new code looks cleaner. Acked-by: Pavel Machek <[email protected]> > @@ -726,14 +726,6 @@ static void memory_bm_clear_bit(struct memory_bitmap > *bm, unsigned long pfn) > clear_bit(bit, addr); > } > > -static void memory_bm_clear_current(struct memory_bitmap *bm) > -{ > - int bit; > - > - bit = max(bm->cur.node_bit - 1, 0); > - clear_bit(bit, bm->cur.node->data); > -} > - > static int memory_bm_test_bit(struct memory_bitmap *bm, unsigned long pfn) > { > void *addr; > @@ -1342,36 +1334,21 @@ static struct memory_bitmap copy_bm; > > void swsusp_free(void) > { > - unsigned long fb_pfn, fr_pfn; > + unsigned long pfn; > > if (!forbidden_pages_map || !free_pages_map) > goto out; > > memory_bm_position_reset(forbidden_pages_map); > - memory_bm_position_reset(free_pages_map); > - > -loop: > - fr_pfn = memory_bm_next_pfn(free_pages_map); > - fb_pfn = memory_bm_next_pfn(forbidden_pages_map); > - > - /* > - * Find the next bit set in both bitmaps. This is guaranteed to > - * terminate when fb_pfn == fr_pfn == BM_END_OF_MAP. > - */ > - do { > - if (fb_pfn < fr_pfn) > - fb_pfn = memory_bm_next_pfn(forbidden_pages_map); > - if (fr_pfn < fb_pfn) > - fr_pfn = memory_bm_next_pfn(free_pages_map); > - } while (fb_pfn != fr_pfn); > - > - if (fr_pfn != BM_END_OF_MAP && pfn_valid(fr_pfn)) { > - struct page *page = pfn_to_page(fr_pfn); > - > - memory_bm_clear_current(forbidden_pages_map); > - memory_bm_clear_current(free_pages_map); > - __free_page(page); > - goto loop; > + for ( ; ; ) { > + pfn = memory_bm_next_pfn(forbidden_pages_map); > + if (BM_END_OF_MAP == pfn) > + break; > + if (memory_bm_test_bit(free_pages_map, pfn)) { > + memory_bm_clear_bit(forbidden_pages_map, pfn); > + memory_bm_clear_bit(free_pages_map, pfn); > + __free_page(pfn_to_page(pfn)); > + } > } > > out: -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
