| Message ID | 20201222074910.GA30051@open-light-1.localdomain (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | add support for free hugepage reporting | expand |
On 22.12.20 08:49, Liang Li wrote: > This patch add support of pre zero out free hugepage, we can use > this feature to speed up page population and page fault handing. > > Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> > Cc: Mel Gorman <mgorman@techsingularity.net> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Dave Hansen <dave.hansen@intel.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Alex Williamson <alex.williamson@redhat.com> > Cc: Michael S. Tsirkin <mst@redhat.com> > Cc: Jason Wang <jasowang@redhat.com> > Cc: Mike Kravetz <mike.kravetz@oracle.com> > Cc: Liang Li <liliang324@gmail.com> > Signed-off-by: Liang Li <liliangleo@didiglobal.com> > --- > mm/page_prezero.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/mm/page_prezero.c b/mm/page_prezero.c > index c8ce720bfc54..dff4e0adf402 100644 > --- a/mm/page_prezero.c > +++ b/mm/page_prezero.c > @@ -26,6 +26,7 @@ static unsigned long delay_millisecs = 1000; > static unsigned long zeropage_enable __read_mostly; > static DEFINE_MUTEX(kzeropaged_mutex); > static struct page_reporting_dev_info zero_page_dev_info; > +static struct page_reporting_dev_info zero_hugepage_dev_info; > > inline void clear_zero_page_flag(struct page *page, int order) > { > @@ -69,9 +70,17 @@ static int start_kzeropaged(void) > zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); > > err = page_reporting_register(&zero_page_dev_info); > + > + zero_hugepage_dev_info.report = zero_free_pages; > + zero_hugepage_dev_info.mini_order = mini_page_order; > + zero_hugepage_dev_info.batch_size = batch_size; > + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); > + > + err |= hugepage_reporting_register(&zero_hugepage_dev_info); > pr_info("Zero page enabled\n"); > } else { > page_reporting_unregister(&zero_page_dev_info); > + hugepage_reporting_unregister(&zero_hugepage_dev_info); > pr_info("Zero page disabled\n"); > } > > @@ -90,7 +99,15 @@ static int restart_kzeropaged(void) > zero_page_dev_info.batch_size = batch_size; > zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); > > + hugepage_reporting_unregister(&zero_hugepage_dev_info); > + > + zero_hugepage_dev_info.report = zero_free_pages; > + zero_hugepage_dev_info.mini_order = mini_page_order; > + zero_hugepage_dev_info.batch_size = batch_size; > + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); > + > err = page_reporting_register(&zero_page_dev_info); > + err |= hugepage_reporting_register(&zero_hugepage_dev_info); > pr_info("Zero page enabled\n"); > } > > Free page reporting in virtio-balloon doesn't give you any guarantees regarding zeroing of pages. Take a look at the QEMU implementation - e.g., with vfio all reports are simply ignored. Also, I am not sure if mangling such details ("zeroing of pages") into the page reporting infrastructure is a good idea.
On 22.12.20 09:31, David Hildenbrand wrote: > On 22.12.20 08:49, Liang Li wrote: >> This patch add support of pre zero out free hugepage, we can use >> this feature to speed up page population and page fault handing. >> >> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> >> Cc: Mel Gorman <mgorman@techsingularity.net> >> Cc: Andrea Arcangeli <aarcange@redhat.com> >> Cc: Dan Williams <dan.j.williams@intel.com> >> Cc: Dave Hansen <dave.hansen@intel.com> >> Cc: David Hildenbrand <david@redhat.com> >> Cc: Michal Hocko <mhocko@suse.com> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Alex Williamson <alex.williamson@redhat.com> >> Cc: Michael S. Tsirkin <mst@redhat.com> >> Cc: Jason Wang <jasowang@redhat.com> >> Cc: Mike Kravetz <mike.kravetz@oracle.com> >> Cc: Liang Li <liliang324@gmail.com> >> Signed-off-by: Liang Li <liliangleo@didiglobal.com> >> --- >> mm/page_prezero.c | 17 +++++++++++++++++ >> 1 file changed, 17 insertions(+) >> >> diff --git a/mm/page_prezero.c b/mm/page_prezero.c >> index c8ce720bfc54..dff4e0adf402 100644 >> --- a/mm/page_prezero.c >> +++ b/mm/page_prezero.c >> @@ -26,6 +26,7 @@ static unsigned long delay_millisecs = 1000; >> static unsigned long zeropage_enable __read_mostly; >> static DEFINE_MUTEX(kzeropaged_mutex); >> static struct page_reporting_dev_info zero_page_dev_info; >> +static struct page_reporting_dev_info zero_hugepage_dev_info; >> >> inline void clear_zero_page_flag(struct page *page, int order) >> { >> @@ -69,9 +70,17 @@ static int start_kzeropaged(void) >> zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> >> err = page_reporting_register(&zero_page_dev_info); >> + >> + zero_hugepage_dev_info.report = zero_free_pages; >> + zero_hugepage_dev_info.mini_order = mini_page_order; >> + zero_hugepage_dev_info.batch_size = batch_size; >> + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> + >> + err |= hugepage_reporting_register(&zero_hugepage_dev_info); >> pr_info("Zero page enabled\n"); >> } else { >> page_reporting_unregister(&zero_page_dev_info); >> + hugepage_reporting_unregister(&zero_hugepage_dev_info); >> pr_info("Zero page disabled\n"); >> } >> >> @@ -90,7 +99,15 @@ static int restart_kzeropaged(void) >> zero_page_dev_info.batch_size = batch_size; >> zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> >> + hugepage_reporting_unregister(&zero_hugepage_dev_info); >> + >> + zero_hugepage_dev_info.report = zero_free_pages; >> + zero_hugepage_dev_info.mini_order = mini_page_order; >> + zero_hugepage_dev_info.batch_size = batch_size; >> + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> + >> err = page_reporting_register(&zero_page_dev_info); >> + err |= hugepage_reporting_register(&zero_hugepage_dev_info); >> pr_info("Zero page enabled\n"); >> } >> >> > > Free page reporting in virtio-balloon doesn't give you any guarantees > regarding zeroing of pages. Take a look at the QEMU implementation - > e.g., with vfio all reports are simply ignored. > > Also, I am not sure if mangling such details ("zeroing of pages") into > the page reporting infrastructure is a good idea. > Oh, now I get what you are doing here, you rely on zero_free_pages of your other patch series and are not relying on virtio-balloon free page reporting to do the zeroing. You really should have mentioned that this patch series relies on the other one and in which way.
> > Free page reporting in virtio-balloon doesn't give you any guarantees > > regarding zeroing of pages. Take a look at the QEMU implementation - > > e.g., with vfio all reports are simply ignored. > > > > Also, I am not sure if mangling such details ("zeroing of pages") into > > the page reporting infrastructure is a good idea. > > > > Oh, now I get what you are doing here, you rely on zero_free_pages of > your other patch series and are not relying on virtio-balloon free page > reporting to do the zeroing. > > You really should have mentioned that this patch series relies on the > other one and in which way. I am sorry for that. After I sent out the patch, I realized I should mention that, so I sent out an updated version which added the information you mentioned :) Thanks ! Liang
diff --git a/mm/page_prezero.c b/mm/page_prezero.c index c8ce720bfc54..dff4e0adf402 100644 --- a/mm/page_prezero.c +++ b/mm/page_prezero.c @@ -26,6 +26,7 @@ static unsigned long delay_millisecs = 1000; static unsigned long zeropage_enable __read_mostly; static DEFINE_MUTEX(kzeropaged_mutex); static struct page_reporting_dev_info zero_page_dev_info; +static struct page_reporting_dev_info zero_hugepage_dev_info; inline void clear_zero_page_flag(struct page *page, int order) { @@ -69,9 +70,17 @@ static int start_kzeropaged(void) zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); err = page_reporting_register(&zero_page_dev_info); + + zero_hugepage_dev_info.report = zero_free_pages; + zero_hugepage_dev_info.mini_order = mini_page_order; + zero_hugepage_dev_info.batch_size = batch_size; + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); + + err |= hugepage_reporting_register(&zero_hugepage_dev_info); pr_info("Zero page enabled\n"); } else { page_reporting_unregister(&zero_page_dev_info); + hugepage_reporting_unregister(&zero_hugepage_dev_info); pr_info("Zero page disabled\n"); } @@ -90,7 +99,15 @@ static int restart_kzeropaged(void) zero_page_dev_info.batch_size = batch_size; zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); + hugepage_reporting_unregister(&zero_hugepage_dev_info); + + zero_hugepage_dev_info.report = zero_free_pages; + zero_hugepage_dev_info.mini_order = mini_page_order; + zero_hugepage_dev_info.batch_size = batch_size; + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); + err = page_reporting_register(&zero_page_dev_info); + err |= hugepage_reporting_register(&zero_hugepage_dev_info); pr_info("Zero page enabled\n"); }
This patch add support of pre zero out free hugepage, we can use this feature to speed up page population and page fault handing. Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Liang Li <liliang324@gmail.com> Signed-off-by: Liang Li <liliangleo@didiglobal.com> --- mm/page_prezero.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)