On Mon, Aug 29, 2022 at 8:19 PM David Hildenbrand <david@xxxxxxxxxx> wrote: > > On 26.08.22 05:23, Zhaoyang Huang wrote: > > On Fri, Aug 26, 2022 at 11:13 AM zhaoyang.huang > > <zhaoyang.huang@xxxxxxxxxx> wrote: > >> > >> From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> > >> > >> It is no need to scan reserved page, skip it. > >> > >> Signed-off-by: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx> > >> --- > >> mm/kmemleak.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/mm/kmemleak.c b/mm/kmemleak.c > >> index a182f5d..c546250 100644 > >> --- a/mm/kmemleak.c > >> +++ b/mm/kmemleak.c > >> @@ -1471,7 +1471,7 @@ static void kmemleak_scan(void) > >> if (page_zone(page) != zone) > >> continue; > >> /* only scan if page is in use */ > >> - if (page_count(page) == 0) > >> + if (page_count(page) == 0 || PageReserved(page)) > > Sorry for previous stupid code by my faint, correct it here > > Did you even test the initial patch? > > I wonder why we should consider this change > > (a) I doubt it's a performance issue. If it is, please provide numbers > before/after. For Android-like SOC systems where AP(cpu runs linux) are one of the memory consumers which are composed of other processors such as modem, isp,wcn etc. The reserved memory occupies a certain number of memory(could be 30% of MemTotal) which makes scan reserved pages pointless. > (b) We'll stop scanning early allocations. As the memmap is usually > allocated early during boot ... we'll stop scanning essentially the > whole mmap and that whole loop would be dead code? What am i > missing? memmap refers to pages here? If we can surpass these as it exist permanently during life period. Besides, I wonder if PageLRU should also be skipped? - if (page_count(page) == 0) + if (page_count(page) == 0 || PageReserved(page) || PageLRU(page)) > > -- > Thanks, > > David / dhildenb >
