| Message ID | 20200225141534.5044-3-mgorman@techsingularity.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Limit runaway reclaim due to watermark boosting | expand |
On Tue, 25 Feb 2020, Mel Gorman wrote: > Watermark boosting is intended to increase the success rate and reduce > latency of high-order allocations, particularly THP. If THP is disabled > at boot, then it makes sense to disable watermark boosting as well. While > there are other high-order allocations that potentially benefit, they > are relatively rare. > > Signed-off-by: Mel Gorman <mgorman@techsingularity.net> > --- > mm/huge_memory.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index b08b199f9a11..565bb9973ff8 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -472,6 +472,7 @@ static int __init setup_transparent_hugepage(char *str) > &transparent_hugepage_flags); > clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, > &transparent_hugepage_flags); > + disable_watermark_boosting(); > ret = 1; > } > out: Seems like watermark boosting can help prevent fragmentation so it benefits all hugepage sized allocations for the long term and that would include dynamic provisioning of hugetlb memory or hugetlb overcommit?
On Tue, Feb 25, 2020 at 05:32:24PM -0800, David Rientjes wrote: > On Tue, 25 Feb 2020, Mel Gorman wrote: > > > Watermark boosting is intended to increase the success rate and reduce > > latency of high-order allocations, particularly THP. If THP is disabled > > at boot, then it makes sense to disable watermark boosting as well. While > > there are other high-order allocations that potentially benefit, they > > are relatively rare. > > > > Signed-off-by: Mel Gorman <mgorman@techsingularity.net> > > --- > > mm/huge_memory.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > index b08b199f9a11..565bb9973ff8 100644 > > --- a/mm/huge_memory.c > > +++ b/mm/huge_memory.c > > @@ -472,6 +472,7 @@ static int __init setup_transparent_hugepage(char *str) > > &transparent_hugepage_flags); > > clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, > > &transparent_hugepage_flags); > > + disable_watermark_boosting(); > > ret = 1; > > } > > out: > > Seems like watermark boosting can help prevent fragmentation so it > benefits all hugepage sized allocations for the long term and that would > include dynamic provisioning of hugetlb memory or hugetlb overcommit? Yes but it's very rare to hear of cases where hugetlb is dynamically provisioned or overcommitted once THP existed and stopped stalling the system excessively. I'm happy enough to drop this patch because I'm not relying on it in the context of this bug.
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index b08b199f9a11..565bb9973ff8 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -472,6 +472,7 @@ static int __init setup_transparent_hugepage(char *str) &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); + disable_watermark_boosting(); ret = 1; } out:
Watermark boosting is intended to increase the success rate and reduce latency of high-order allocations, particularly THP. If THP is disabled at boot, then it makes sense to disable watermark boosting as well. While there are other high-order allocations that potentially benefit, they are relatively rare. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> --- mm/huge_memory.c | 1 + 1 file changed, 1 insertion(+)