search for: thp

...> >>>>> On 22 Jun 2020, at 15:36, Ralph Campbell wrote: > >>>>>> On 6/21/20 4:20 PM, Zi Yan wrote: > >>>>>>> On 19 Jun 2020, at 17:56, Ralph Campbell wrote: > ... > >>> Ying(cc?d) developed the code to swapout and swapin THP in one piece: https://lore.kernel.org/linux-mm/20181207054122.27822-1-ying.huang at intel.com/. > >>> I am not sure whether the patchset makes into mainstream or not. It could be a good technical reference > >>> for swapping in device private pages, although swapping in page...

...page_remove_rmap(page, true); > > >>>>> VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); > > >>>>> VM_BUG_ON_PAGE(!PageHead(page), page); > > >>>>> } else if (thp_migration_supported()) { > > >>>>> swp_entry_t entry; > > >>>>> > > >>>>> - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); > > >>>>> entry = pmd_to_...

...;>>> On 22 Jun 2020, at 15:36, Ralph Campbell wrote: >>>>>>>> On 6/21/20 4:20 PM, Zi Yan wrote: >>>>>>>>> On 19 Jun 2020, at 17:56, Ralph Campbell wrote: >> ... >>>>> Ying(cc?d) developed the code to swapout and swapin THP in one piece: https://lore.kernel.org/linux-mm/20181207054122.27822-1-ying.huang at intel.com/. >>>>> I am not sure whether the patchset makes into mainstream or not. It could be a good technical reference >>>>> for swapping in device private pages, although swapping i...

On 12.03.20 08:49, Hui Zhu wrote: > If the guest kernel has many fragmentation pages, use virtio_balloon > will split THP of QEMU when it calls MADV_DONTNEED madvise to release > the balloon pages. > This is an example in a VM with 1G memory 1CPU: > cat /proc/meminfo | grep AnonHugePages: > AnonHugePages: 0 kB > > usemem --punch-holes -s -1 800m & > > cat /proc/meminfo | grep Anon...

On 12.03.20 08:49, Hui Zhu wrote: > If the guest kernel has many fragmentation pages, use virtio_balloon > will split THP of QEMU when it calls MADV_DONTNEED madvise to release > the balloon pages. > This is an example in a VM with 1G memory 1CPU: > cat /proc/meminfo | grep AnonHugePages: > AnonHugePages: 0 kB > > usemem --punch-holes -s -1 800m & > > cat /proc/meminfo | grep Anon...

On 19 Jun 2020, at 17:56, Ralph Campbell wrote: > Transparent huge page allocation policy is controlled by several sysfs > variables. Rather than expose these to each device driver that needs to > allocate THPs, provide a helper function. > > Signed-off-by: Ralph Campbell <rcampbell at nvidia.com> > --- > include/linux/gfp.h | 10 ++++++++++ > mm/huge_memory.c | 16 ++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/include/linux/gfp.h b/include/linux/...

.... Berrange <berrange@redhat.com> wrote: > IOW, if your application has a certain expectation of performance that can only > be satisfied by having the KVM guest backed by huge pages, then you should > really change to explicitly reserve huge pages for the guests, and not rely on > THP which inherantly can't provide any guarantee in this area. We already do this. The problem is not hugepage backing of the guest, it is THP allocation inside the guest (or indeed on a bare-metal host). The issue in the HPC world is that we support so many different applications (some of which a...

...20 1:10 PM, Zi Yan wrote: >>>>> On 22 Jun 2020, at 15:36, Ralph Campbell wrote: >>>>>> On 6/21/20 4:20 PM, Zi Yan wrote: >>>>>>> On 19 Jun 2020, at 17:56, Ralph Campbell wrote: ... >>> Ying(cc?d) developed the code to swapout and swapin THP in one piece: https://lore.kernel.org/linux-mm/20181207054122.27822-1-ying.huang at intel.com/. >>> I am not sure whether the patchset makes into mainstream or not. It could be a good technical reference >>> for swapping in device private pages, although swapping in pages from dis...

...(orig_pmd); >>>>> + is_anon = PageAnon(page); >>>>> page_remove_rmap(page, true); >>>>> VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); >>>>> VM_BUG_ON_PAGE(!PageHead(page), page); >>>>> } else if (thp_migration_supported()) { >>>>> swp_entry_t entry; >>>>> >>>>> - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); >>>>> entry = pmd_to_swp_entry(orig_pmd); >>>>> - page = pfn_to_page(swp_offset(entry)); >>&...

...ming the page is mapped. Also, if the PMD entry is a migration PMD entry, the call to is_huge_zero_pmd(*pmd) is incorrect because it calls pmd_pfn(pmd) instead of migration_entry_to_pfn(pmd_to_swp_entry(pmd)). Fix these problems by checking for a PMD migration entry. Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") cc: stable at vger.kernel.org # 4.14+ Signed-off-by: Ralph Campbell <rcampbell at nvidia.com> Reviewed-by: Yang Shi <shy828301 at gmail.com> Reviewed-by: Zi Yan <ziy at nvidia.com> --- No changes in v3 to this patch, just added rev...

...page_remove_rmap(page, true); > >>>>> VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); > >>>>> VM_BUG_ON_PAGE(!PageHead(page), page); > >>>>> } else if (thp_migration_supported()) { > >>>>> swp_entry_t entry; > >>>>> > >>>>> - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); > >>>>> entry = pmd_to_swp_entry(orig_pmd);...

Transparent huge page allocation policy is controlled by several sysfs variables. Rather than expose these to each device driver that needs to allocate THPs, provide a helper function. Signed-off-by: Ralph Campbell <rcampbell at nvidia.com> --- include/linux/gfp.h | 10 ++++++++++ mm/huge_memory.c | 16 ++++++++++++++++ 2 files changed, 26 insertions(+) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 67a0774e080b..1c7d968a27d3...

...ault one page at a time > mm/hmm: add output flag for compound page mapping > nouveau/hmm: support mapping large sysmem pages > hmm: add tests for HMM_PFN_COMPOUND flag > mm/hmm: optimize migrate_vma_setup() for holes Order things so it is hmm, test, noeveau > mm: support THP migration to device private memory > mm/thp: add THP allocation helper > mm/hmm/test: add self tests for THP migration > nouveau: support THP migration to private memory This is another series, you should split it even if it has to go through the hmm tree Jason

Transparent huge page allocation policy is controlled by several sysfs variables. Rather than expose these to each device driver that needs to allocate THPs, provide a helper function. Signed-off-by: Ralph Campbell <rcampbell at nvidia.com> --- include/linux/gfp.h | 10 ++++++++++ mm/huge_memory.c | 14 ++++++++++++++ 2 files changed, 24 insertions(+) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index c603237e006c..242398c4b556 1...

...ig_pmd)) { >>> page = pmd_page(orig_pmd); >>> + is_anon = PageAnon(page); >>> page_remove_rmap(page, true); >>> VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); >>> VM_BUG_ON_PAGE(!PageHead(page), page); >>> } else if (thp_migration_supported()) { >>> swp_entry_t entry; >>> >>> - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); >>> entry = pmd_to_swp_entry(orig_pmd); >>> - page = pfn_to_page(swp_offset(entry)); >>> + if (is_device_private_entry(entry)...

On Thu, Mar 12, 2020 at 03:49:55PM +0800, Hui Zhu wrote: > If the guest kernel has many fragmentation pages, use virtio_balloon > will split THP of QEMU when it calls MADV_DONTNEED madvise to release > the balloon pages. > Set option thp-order to on will open flags VIRTIO_BALLOON_F_THP_ORDER. > It will set balloon size to THP size to handle the THP split issue. > > Signed-off-by: Hui Zhu <teawaterz at linux.alibaba.com&gt...

On Thu, Mar 12, 2020 at 03:49:54PM +0800, Hui Zhu wrote: > If the guest kernel has many fragmentation pages, use virtio_balloon > will split THP of QEMU when it calls MADV_DONTNEED madvise to release > the balloon pages. > This is an example in a VM with 1G memory 1CPU: > cat /proc/meminfo | grep AnonHugePages: > AnonHugePages: 0 kB > > usemem --punch-holes -s -1 800m & > > cat /proc/meminfo | grep Anon...

...g, balloon tries to use continuous pages to inflate and deflate. > Opening this flag can bring two benefits: > 1. Report continuous pages will increase memory report size of each time > call tell_host. Then it will increase the speed of balloon inflate and > deflate. > 2. Host THPs will be splitted when qemu release the page of balloon inflate. > Inflate balloon with continuous pages will let QEMU release the pages > of same THPs. That will help decrease the splitted THPs number in > the host. > Following is an example in a VM with 1G memory 1CPU. T...

...nge@redhat.com> wrote: > > IOW, if your application has a certain expectation of performance that can only > > be satisfied by having the KVM guest backed by huge pages, then you should > > really change to explicitly reserve huge pages for the guests, and not rely on > > THP which inherantly can't provide any guarantee in this area. > > We already do this. The problem is not hugepage backing of the guest, > it is THP allocation inside the guest (or indeed on a bare-metal > host). The issue in the HPC world is that we support so many different > appl...

...page = pmd_page(orig_pmd); >>>> + is_anon = PageAnon(page); >>>> page_remove_rmap(page, true); >>>> VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); >>>> VM_BUG_ON_PAGE(!PageHead(page), page); >>>> } else if (thp_migration_supported()) { >>>> swp_entry_t entry; >>>> >>>> - VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); >>>> entry = pmd_to_swp_entry(orig_pmd); >>>> - page = pfn_to_page(swp_offset(entry)); >>>> + if (is_d...