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Date: Thu, 19 Mar 2015 17:28:58 +0900 From: "Tom(JeHyeon) Yeon" <tomyeon750415lkml@...il.com> To: pavel@....cz, len.brown@...el.com, jroedel@...e.de, linux-pm@...r.kernel.org Cc: linux-kernel@...r.kernel.org, "Tom(JeHyeon) Yeon" <tom.yeon@...driver.com> Subject: [PATCH] PM / Hiberante : optimize swsusp_free() From: "Tom(JeHyeon) Yeon" <tom.yeon@...driver.com> 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 <tom.yeon@...driver.com> --- kernel/power/snapshot.c | 43 ++++++++++--------------------------------- 1 file changed, 10 insertions(+), 33 deletions(-) diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index c24d5a2..a1ad801 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -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: -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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