| Message ID | 1567576823-10080-1-git-send-email-shuang.qiu@oracle.com |
|---|---|
| State | Changes Requested |
| Delegated to: | Petr Vorel |
| Headers | show |
| Series | madvise09:Change PAGES size to the value more than 32 | expand |
On Wed, Sep 04, 2019 at 02:00:23PM +0800, shuang.qiu@oracle.com wrote: > From: Shuang Qiu <shuang.qiu@oracle.com> > > In upstream patch 1a61ab (mm: memcontrol: replace zone summing with lruvec_page_state()), > it modify the lruvec state in batch,equal and less than 32 MADV_FREE pages will not trigger > the account of lruvec_stat,and will not be free in memory pressure either. > So the testcase may fail with: > ... > madvise09.c:219: INFO: Memory hungry child 6178 started, try 10 > madvise09.c:254: INFO: Memory map: pppppppppppppppppppppppppppppppp > madvise09.c:259: FAIL: No MADV_FREE page was freed on low memory > ... > Change the PAGES to the value more than 32 can fix such issue. > > Signed-off-by: Shuang Qiu <shuang.qiu@oracle.com> On ppc64le, I was getting retries, as OOM was getting hit. The test would ultimately time out. This fixes it for me. Thanks. Cascardo. Tested-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> > --- > testcases/kernel/syscalls/madvise/madvise09.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/testcases/kernel/syscalls/madvise/madvise09.c b/testcases/kernel/syscalls/madvise/madvise09.c > index 01075f6..3759053 100644 > --- a/testcases/kernel/syscalls/madvise/madvise09.c > +++ b/testcases/kernel/syscalls/madvise/madvise09.c > @@ -57,7 +57,7 @@ static int sleep_between_faults; > > static int swap_accounting_enabled; > > -#define PAGES 32 > +#define PAGES 64 > #define TOUCHED_PAGE1 0 > #define TOUCHED_PAGE2 10 > > -- > 1.9.1 > > > -- > Mailing list info: https://lists.linux.it/listinfo/ltp
On Wed, Sep 4, 2019 at 2:01 PM <shuang.qiu@oracle.com> wrote: > > From: Shuang Qiu <shuang.qiu@oracle.com> > > In upstream patch 1a61ab (mm: memcontrol: replace zone summing with lruvec_page_state()), > it modify the lruvec state in batch,equal and less than 32 MADV_FREE pages will not trigger > the account of lruvec_stat,and will not be free in memory pressure either. > So the testcase may fail with: > ... > madvise09.c:219: INFO: Memory hungry child 6178 started, try 10 > madvise09.c:254: INFO: Memory map: pppppppppppppppppppppppppppppppp > madvise09.c:259: FAIL: No MADV_FREE page was freed on low memory > ... > Change the PAGES to the value more than 32 can fix such issue. > > Signed-off-by: Shuang Qiu <shuang.qiu@oracle.com> > --- > testcases/kernel/syscalls/madvise/madvise09.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/testcases/kernel/syscalls/madvise/madvise09.c b/testcases/kernel/syscalls/madvise/madvise09.c > index 01075f6..3759053 100644 > --- a/testcases/kernel/syscalls/madvise/madvise09.c > +++ b/testcases/kernel/syscalls/madvise/madvise09.c > @@ -57,7 +57,7 @@ static int sleep_between_faults; > > static int swap_accounting_enabled; > > -#define PAGES 32 > +#define PAGES 64 I'm not sure why 64 pages is a proper value? Can you explain more?
On 09/05/2019 04:29 PM, Li Wang wrote: > On Wed, Sep 4, 2019 at 2:01 PM <shuang.qiu@oracle.com> wrote: >> From: Shuang Qiu <shuang.qiu@oracle.com> >> >> In upstream patch 1a61ab (mm: memcontrol: replace zone summing with lruvec_page_state()), >> it modify the lruvec state in batch,equal and less than 32 MADV_FREE pages will not trigger >> the account of lruvec_stat,and will not be free in memory pressure either. >> So the testcase may fail with: >> ... >> madvise09.c:219: INFO: Memory hungry child 6178 started, try 10 >> madvise09.c:254: INFO: Memory map: pppppppppppppppppppppppppppppppp >> madvise09.c:259: FAIL: No MADV_FREE page was freed on low memory >> ... >> Change the PAGES to the value more than 32 can fix such issue. >> >> Signed-off-by: Shuang Qiu <shuang.qiu@oracle.com> >> --- >> testcases/kernel/syscalls/madvise/madvise09.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/testcases/kernel/syscalls/madvise/madvise09.c b/testcases/kernel/syscalls/madvise/madvise09.c >> index 01075f6..3759053 100644 >> --- a/testcases/kernel/syscalls/madvise/madvise09.c >> +++ b/testcases/kernel/syscalls/madvise/madvise09.c >> @@ -57,7 +57,7 @@ static int sleep_between_faults; >> >> static int swap_accounting_enabled; >> >> -#define PAGES 32 >> +#define PAGES 64 > I'm not sure why 64 pages is a proper value? Can you explain more? I think any value which larger than 32 is ok. So I tested 64 and works fine. Thanks Shuang >
On Thu, Sep 5, 2019 at 6:02 PM Shuang Qiu <shuang.qiu@oracle.com> wrote: > > On 09/05/2019 04:29 PM, Li Wang wrote: > > On Wed, Sep 4, 2019 at 2:01 PM <shuang.qiu@oracle.com> wrote: > >> From: Shuang Qiu <shuang.qiu@oracle.com> > >> > >> In upstream patch 1a61ab (mm: memcontrol: replace zone summing with lruvec_page_state()), > >> it modify the lruvec state in batch,equal and less than 32 MADV_FREE pages will not trigger > >> the account of lruvec_stat,and will not be free in memory pressure either. > >> So the testcase may fail with: > >> ... > >> madvise09.c:219: INFO: Memory hungry child 6178 started, try 10 > >> madvise09.c:254: INFO: Memory map: pppppppppppppppppppppppppppppppp > >> madvise09.c:259: FAIL: No MADV_FREE page was freed on low memory > >> ... > >> Change the PAGES to the value more than 32 can fix such issue. > >> > >> Signed-off-by: Shuang Qiu <shuang.qiu@oracle.com> > >> --- > >> testcases/kernel/syscalls/madvise/madvise09.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/testcases/kernel/syscalls/madvise/madvise09.c b/testcases/kernel/syscalls/madvise/madvise09.c > >> index 01075f6..3759053 100644 > >> --- a/testcases/kernel/syscalls/madvise/madvise09.c > >> +++ b/testcases/kernel/syscalls/madvise/madvise09.c > >> @@ -57,7 +57,7 @@ static int sleep_between_faults; > >> > >> static int swap_accounting_enabled; > >> > >> -#define PAGES 32 > >> +#define PAGES 64 > > I'm not sure why 64 pages is a proper value? Can you explain more? > I think any value which larger than 32 is ok. > So I tested 64 and works fine. I just tried with '42' randomly, but it doesn't work. I guess that might have a waterline to trigger this memory page reclaiming. I looked at the code calling path, it seems the 'sc->nr_reclaimed' is the key value to control that, but still not 100% sure, I will keep debugging it for a while. try_to_free_mem_cgroup_pages do_try_to_free_pages shrink_zone shrink_node shrink_node_memcg get_scan_count lruvec_lru_size lruvec_page_state
Hi!
> I'm not sure why 64 pages is a proper value? Can you explain more?
I've just talked to Michal Hocko and the conclusion is that we should
allocate several megabytes to avoid depending kernel implementation
details, which would mean allocating thousands of pages.
On Wed, Sep 11, 2019 at 7:19 PM Cyril Hrubis <chrubis@suse.cz> wrote: > Hi! > > I'm not sure why 64 pages is a proper value? Can you explain more? > > I've just talked to Michal Hocko and the conclusion is that we should > allocate several megabytes to avoid depending kernel implementation > details, which would mean allocating thousands of pages. > Sounds reasonable. Allocating thousands of pages must trigger the MADV_FREE page reclaiming. @shuang.qiu, Hi Shuang, would you mind to rewrite the patch, or should I do that?
On 09/12/2019 10:51 AM, Li Wang wrote: > > > On Wed, Sep 11, 2019 at 7:19 PM Cyril Hrubis <chrubis@suse.cz > <mailto:chrubis@suse.cz>> wrote: > > Hi! > > I'm not sure why 64 pages is a proper value? Can you explain more? > > I've just talked to Michal Hocko and the conclusion is that we should > allocate several megabytes to avoid depending kernel implementation > details, which would mean allocating thousands of pages. > > > Sounds reasonable. Allocating thousands of pages must trigger > the MADV_FREE page reclaiming. > > @shuang.qiu, Hi Shuang, would you mind to rewrite the patch, or should > I do that? Thanks for helping to investigate this issue. I will update the patch. 32 pages is really small in current system which may be held on reclaiming small piece of memory,thousands of pages is reasonable. Thanks Shuang > > -- > Regards, > Li Wang
diff --git a/testcases/kernel/syscalls/madvise/madvise09.c b/testcases/kernel/syscalls/madvise/madvise09.c index 01075f6..3759053 100644 --- a/testcases/kernel/syscalls/madvise/madvise09.c +++ b/testcases/kernel/syscalls/madvise/madvise09.c @@ -57,7 +57,7 @@ static int sleep_between_faults; static int swap_accounting_enabled; -#define PAGES 32 +#define PAGES 64 #define TOUCHED_PAGE1 0 #define TOUCHED_PAGE2 10