Messages in this thread | | | Date | Wed, 7 Jun 2017 12:56:57 +0800 | From | zhong jiang <> | Subject | Re: [PATCH] Revert "mm: vmpressure: fix sending wrong events on underflow" |
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On 2017/6/7 11:55, Minchan Kim wrote: > On Wed, Jun 07, 2017 at 11:08:37AM +0800, zhongjiang wrote: >> This reverts commit e1587a4945408faa58d0485002c110eb2454740c. >> >> THP lru page is reclaimed , THP is split to normal page and loop again. >> reclaimed pages should not be bigger than nr_scan. because of each >> loop will increase nr_scan counter. > Unfortunately, there is still underflow issue caused by slab pages as > Vinayak reported in description of e1587a4945408 so we cannot revert. > Please correct comment instead of removing the logic. > > Thanks. we calculate the vmpressue based on the Lru page, exclude the slab pages by previous discussion. is it not this?
Thanks zhongjiang >> Signed-off-by: zhongjiang <zhongjiang@huawei.com> >> --- >> mm/vmpressure.c | 10 +--------- >> 1 file changed, 1 insertion(+), 9 deletions(-) >> >> diff --git a/mm/vmpressure.c b/mm/vmpressure.c >> index 6063581..149fdf6 100644 >> --- a/mm/vmpressure.c >> +++ b/mm/vmpressure.c >> @@ -112,16 +112,9 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned, >> unsigned long reclaimed) >> { >> unsigned long scale = scanned + reclaimed; >> - unsigned long pressure = 0; >> + unsigned long pressure; >> >> /* >> - * reclaimed can be greater than scanned in cases >> - * like THP, where the scanned is 1 and reclaimed >> - * could be 512 >> - */ >> - if (reclaimed >= scanned) >> - goto out; >> - /* >> * We calculate the ratio (in percents) of how many pages were >> * scanned vs. reclaimed in a given time frame (window). Note that >> * time is in VM reclaimer's "ticks", i.e. number of pages >> @@ -131,7 +124,6 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned, >> pressure = scale - (reclaimed * scale / scanned); >> pressure = pressure * 100 / scale; >> >> -out: >> pr_debug("%s: %3lu (s: %lu r: %lu)\n", __func__, pressure, >> scanned, reclaimed); >> >> -- >> 1.7.12.4 >> > . >
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