Re: [PATCH] hugetlb_cgroup: fix reservation accounting
On Thu, Oct 22, 2020 at 5:21 AM Michael S. Tsirkin wrote: > > On Wed, Oct 21, 2020 at 01:44:26PM -0700, Mike Kravetz wrote: > > Michal Privoznik was using "free page reporting" in QEMU/virtio-balloon > > with hugetlbfs and hit the warning below. QEMU with free page hinting > > uses fallocate(FALLOC_FL_PUNCH_HOLE) to discard pages that are reported > > as free by a VM. The reporting granularity is in pageblock granularity. > > So when the guest reports 2M chunks, we fallocate(FALLOC_FL_PUNCH_HOLE) > > one huge page in QEMU. > > > > [ 315.251417] [ cut here ] > > [ 315.251424] WARNING: CPU: 7 PID: 6636 at mm/page_counter.c:57 > > page_counter_uncharge+0x4b/0x50 > > [ 315.251425] Modules linked in: ... > > [ 315.251466] CPU: 7 PID: 6636 Comm: qemu-system-x86 Not tainted 5.9.0 #137 > > [ 315.251467] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS > > PRO/X570 AORUS PRO, BIOS F21 07/31/2020 > > [ 315.251469] RIP: 0010:page_counter_uncharge+0x4b/0x50 > > ... > > [ 315.251479] Call Trace: > > [ 315.251485] hugetlb_cgroup_uncharge_file_region+0x4b/0x80 > > [ 315.251487] region_del+0x1d3/0x300 > > [ 315.251489] hugetlb_unreserve_pages+0x39/0xb0 > > [ 315.251492] remove_inode_hugepages+0x1a8/0x3d0 > > [ 315.251495] ? tlb_finish_mmu+0x7a/0x1d0 > > [ 315.251497] hugetlbfs_fallocate+0x3c4/0x5c0 > > [ 315.251519] ? kvm_arch_vcpu_ioctl_run+0x614/0x1700 [kvm] > > [ 315.251522] ? file_has_perm+0xa2/0xb0 > > [ 315.251524] ? inode_security+0xc/0x60 > > [ 315.251525] ? selinux_file_permission+0x4e/0x120 > > [ 315.251527] vfs_fallocate+0x146/0x290 > > [ 315.251529] __x64_sys_fallocate+0x3e/0x70 > > [ 315.251531] do_syscall_64+0x33/0x40 > > [ 315.251533] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > ... > > [ 315.251542] ---[ end trace 4c88c62ccb1349c9 ]--- > > > > Investigation of the issue uncovered bugs in hugetlb cgroup reservation > > accounting. This patch addresses the found issues. > > > > Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings") > > Cc: > > Reported-by: Michal Privoznik > > Co-developed-by: David Hildenbrand > > Signed-off-by: David Hildenbrand > > Signed-off-by: Mike Kravetz > > Acked-by: Michael S. Tsirkin > > > --- > > mm/hugetlb.c | 20 +++- > > 1 file changed, 11 insertions(+), 9 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 67fc6383995b..b853a11de14f 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -655,6 +655,8 @@ static long region_del(struct resv_map *resv, long f, > > long t) > > } > > > > del += t - f; > > + hugetlb_cgroup_uncharge_file_region( > > + resv, rg, t - f); > > > > /* New entry for end of split region */ > > nrg->from = t; > > @@ -667,9 +669,6 @@ static long region_del(struct resv_map *resv, long f, > > long t) > > /* Original entry is trimmed */ > > rg->to = f; > > > > - hugetlb_cgroup_uncharge_file_region( > > - resv, rg, nrg->to - nrg->from); > > - > > list_add(>link, >link); > > nrg = NULL; > > break; > > @@ -685,17 +684,17 @@ static long region_del(struct resv_map *resv, long f, > > long t) > > } > > > > if (f <= rg->from) {/* Trim beginning of region */ > > - del += t - rg->from; > > - rg->from = t; > > - > > hugetlb_cgroup_uncharge_file_region(resv, rg, > > t - rg->from); > > - } else {/* Trim end of region */ > > - del += rg->to - f; > > - rg->to = f; > > > > + del += t - rg->from; > > + rg->from = t; > > + } else {/* Trim end of region */ > > hugetlb_cgroup_uncharge_file_region(resv, rg, > > rg->to - f); > > + > > + del += rg->to - f; > > + rg->to = f; > > } > > } > > > > @@ -2454,6 +2453,9 @@ struct page *alloc_huge_page(struct vm_area_struct > > *vma, > > > > rsv_adjust = hugepage_subpool_put_pages(spool, 1); > > hugetlb_acct_memory(h, -rsv_adjust); > > + if (deferred_reserve) > > + hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), > > + pages_per_huge_page(h), page); > > } > > return page; > > > > -- > > 2.25.4 > Sorry for the late review. Looks good to me. Reviewed-by: Mina Almasry
Re: [PATCH] hugetlb_cgroup: fix reservation accounting
On Wed, Oct 21, 2020 at 01:44:26PM -0700, Mike Kravetz wrote: > Michal Privoznik was using "free page reporting" in QEMU/virtio-balloon > with hugetlbfs and hit the warning below. QEMU with free page hinting > uses fallocate(FALLOC_FL_PUNCH_HOLE) to discard pages that are reported > as free by a VM. The reporting granularity is in pageblock granularity. > So when the guest reports 2M chunks, we fallocate(FALLOC_FL_PUNCH_HOLE) > one huge page in QEMU. > > [ 315.251417] [ cut here ] > [ 315.251424] WARNING: CPU: 7 PID: 6636 at mm/page_counter.c:57 > page_counter_uncharge+0x4b/0x50 > [ 315.251425] Modules linked in: ... > [ 315.251466] CPU: 7 PID: 6636 Comm: qemu-system-x86 Not tainted 5.9.0 #137 > [ 315.251467] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS > PRO/X570 AORUS PRO, BIOS F21 07/31/2020 > [ 315.251469] RIP: 0010:page_counter_uncharge+0x4b/0x50 > ... > [ 315.251479] Call Trace: > [ 315.251485] hugetlb_cgroup_uncharge_file_region+0x4b/0x80 > [ 315.251487] region_del+0x1d3/0x300 > [ 315.251489] hugetlb_unreserve_pages+0x39/0xb0 > [ 315.251492] remove_inode_hugepages+0x1a8/0x3d0 > [ 315.251495] ? tlb_finish_mmu+0x7a/0x1d0 > [ 315.251497] hugetlbfs_fallocate+0x3c4/0x5c0 > [ 315.251519] ? kvm_arch_vcpu_ioctl_run+0x614/0x1700 [kvm] > [ 315.251522] ? file_has_perm+0xa2/0xb0 > [ 315.251524] ? inode_security+0xc/0x60 > [ 315.251525] ? selinux_file_permission+0x4e/0x120 > [ 315.251527] vfs_fallocate+0x146/0x290 > [ 315.251529] __x64_sys_fallocate+0x3e/0x70 > [ 315.251531] do_syscall_64+0x33/0x40 > [ 315.251533] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > ... > [ 315.251542] ---[ end trace 4c88c62ccb1349c9 ]--- > > Investigation of the issue uncovered bugs in hugetlb cgroup reservation > accounting. This patch addresses the found issues. > > Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings") > Cc: > Reported-by: Michal Privoznik > Co-developed-by: David Hildenbrand > Signed-off-by: David Hildenbrand > Signed-off-by: Mike Kravetz Acked-by: Michael S. Tsirkin > --- > mm/hugetlb.c | 20 +++- > 1 file changed, 11 insertions(+), 9 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index 67fc6383995b..b853a11de14f 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -655,6 +655,8 @@ static long region_del(struct resv_map *resv, long f, > long t) > } > > del += t - f; > + hugetlb_cgroup_uncharge_file_region( > + resv, rg, t - f); > > /* New entry for end of split region */ > nrg->from = t; > @@ -667,9 +669,6 @@ static long region_del(struct resv_map *resv, long f, > long t) > /* Original entry is trimmed */ > rg->to = f; > > - hugetlb_cgroup_uncharge_file_region( > - resv, rg, nrg->to - nrg->from); > - > list_add(>link, >link); > nrg = NULL; > break; > @@ -685,17 +684,17 @@ static long region_del(struct resv_map *resv, long f, > long t) > } > > if (f <= rg->from) {/* Trim beginning of region */ > - del += t - rg->from; > - rg->from = t; > - > hugetlb_cgroup_uncharge_file_region(resv, rg, > t - rg->from); > - } else {/* Trim end of region */ > - del += rg->to - f; > - rg->to = f; > > + del += t - rg->from; > + rg->from = t; > + } else {/* Trim end of region */ > hugetlb_cgroup_uncharge_file_region(resv, rg, > rg->to - f); > + > + del += rg->to - f; > + rg->to = f; > } > } > > @@ -2454,6 +2453,9 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, > > rsv_adjust = hugepage_subpool_put_pages(spool, 1); > hugetlb_acct_memory(h, -rsv_adjust); > + if (deferred_reserve) > + hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), > + pages_per_huge_page(h), page); > } > return page; > > -- > 2.25.4
Re: [PATCH] hugetlb_cgroup: fix reservation accounting
On 10/21/20 10:44 PM, Mike Kravetz wrote: Michal Privoznik was using "free page reporting" in QEMU/virtio-balloon with hugetlbfs and hit the warning below. QEMU with free page hinting uses fallocate(FALLOC_FL_PUNCH_HOLE) to discard pages that are reported as free by a VM. The reporting granularity is in pageblock granularity. So when the guest reports 2M chunks, we fallocate(FALLOC_FL_PUNCH_HOLE) one huge page in QEMU. [ 315.251417] [ cut here ] [ 315.251424] WARNING: CPU: 7 PID: 6636 at mm/page_counter.c:57 page_counter_uncharge+0x4b/0x50 [ 315.251425] Modules linked in: ... [ 315.251466] CPU: 7 PID: 6636 Comm: qemu-system-x86 Not tainted 5.9.0 #137 [ 315.251467] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO/X570 AORUS PRO, BIOS F21 07/31/2020 [ 315.251469] RIP: 0010:page_counter_uncharge+0x4b/0x50 ... [ 315.251479] Call Trace: [ 315.251485] hugetlb_cgroup_uncharge_file_region+0x4b/0x80 [ 315.251487] region_del+0x1d3/0x300 [ 315.251489] hugetlb_unreserve_pages+0x39/0xb0 [ 315.251492] remove_inode_hugepages+0x1a8/0x3d0 [ 315.251495] ? tlb_finish_mmu+0x7a/0x1d0 [ 315.251497] hugetlbfs_fallocate+0x3c4/0x5c0 [ 315.251519] ? kvm_arch_vcpu_ioctl_run+0x614/0x1700 [kvm] [ 315.251522] ? file_has_perm+0xa2/0xb0 [ 315.251524] ? inode_security+0xc/0x60 [ 315.251525] ? selinux_file_permission+0x4e/0x120 [ 315.251527] vfs_fallocate+0x146/0x290 [ 315.251529] __x64_sys_fallocate+0x3e/0x70 [ 315.251531] do_syscall_64+0x33/0x40 [ 315.251533] entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... [ 315.251542] ---[ end trace 4c88c62ccb1349c9 ]--- Investigation of the issue uncovered bugs in hugetlb cgroup reservation accounting. This patch addresses the found issues. Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings") Cc: Reported-by: Michal Privoznik Co-developed-by: David Hildenbrand Signed-off-by: David Hildenbrand Signed-off-by: Mike Kravetz --- mm/hugetlb.c | 20 +++- 1 file changed, 11 insertions(+), 9 deletions(-) I just tested this and can confirm it fixes the problem: Tested-by: Michal Privoznik Thank you! Michal
[PATCH] hugetlb_cgroup: fix reservation accounting
Michal Privoznik was using "free page reporting" in QEMU/virtio-balloon with hugetlbfs and hit the warning below. QEMU with free page hinting uses fallocate(FALLOC_FL_PUNCH_HOLE) to discard pages that are reported as free by a VM. The reporting granularity is in pageblock granularity. So when the guest reports 2M chunks, we fallocate(FALLOC_FL_PUNCH_HOLE) one huge page in QEMU. [ 315.251417] [ cut here ] [ 315.251424] WARNING: CPU: 7 PID: 6636 at mm/page_counter.c:57 page_counter_uncharge+0x4b/0x50 [ 315.251425] Modules linked in: ... [ 315.251466] CPU: 7 PID: 6636 Comm: qemu-system-x86 Not tainted 5.9.0 #137 [ 315.251467] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO/X570 AORUS PRO, BIOS F21 07/31/2020 [ 315.251469] RIP: 0010:page_counter_uncharge+0x4b/0x50 ... [ 315.251479] Call Trace: [ 315.251485] hugetlb_cgroup_uncharge_file_region+0x4b/0x80 [ 315.251487] region_del+0x1d3/0x300 [ 315.251489] hugetlb_unreserve_pages+0x39/0xb0 [ 315.251492] remove_inode_hugepages+0x1a8/0x3d0 [ 315.251495] ? tlb_finish_mmu+0x7a/0x1d0 [ 315.251497] hugetlbfs_fallocate+0x3c4/0x5c0 [ 315.251519] ? kvm_arch_vcpu_ioctl_run+0x614/0x1700 [kvm] [ 315.251522] ? file_has_perm+0xa2/0xb0 [ 315.251524] ? inode_security+0xc/0x60 [ 315.251525] ? selinux_file_permission+0x4e/0x120 [ 315.251527] vfs_fallocate+0x146/0x290 [ 315.251529] __x64_sys_fallocate+0x3e/0x70 [ 315.251531] do_syscall_64+0x33/0x40 [ 315.251533] entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... [ 315.251542] ---[ end trace 4c88c62ccb1349c9 ]--- Investigation of the issue uncovered bugs in hugetlb cgroup reservation accounting. This patch addresses the found issues. Fixes: 075a61d07a8e ("hugetlb_cgroup: add accounting for shared mappings") Cc: Reported-by: Michal Privoznik Co-developed-by: David Hildenbrand Signed-off-by: David Hildenbrand Signed-off-by: Mike Kravetz --- mm/hugetlb.c | 20 +++- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 67fc6383995b..b853a11de14f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -655,6 +655,8 @@ static long region_del(struct resv_map *resv, long f, long t) } del += t - f; + hugetlb_cgroup_uncharge_file_region( + resv, rg, t - f); /* New entry for end of split region */ nrg->from = t; @@ -667,9 +669,6 @@ static long region_del(struct resv_map *resv, long f, long t) /* Original entry is trimmed */ rg->to = f; - hugetlb_cgroup_uncharge_file_region( - resv, rg, nrg->to - nrg->from); - list_add(>link, >link); nrg = NULL; break; @@ -685,17 +684,17 @@ static long region_del(struct resv_map *resv, long f, long t) } if (f <= rg->from) {/* Trim beginning of region */ - del += t - rg->from; - rg->from = t; - hugetlb_cgroup_uncharge_file_region(resv, rg, t - rg->from); - } else {/* Trim end of region */ - del += rg->to - f; - rg->to = f; + del += t - rg->from; + rg->from = t; + } else {/* Trim end of region */ hugetlb_cgroup_uncharge_file_region(resv, rg, rg->to - f); + + del += rg->to - f; + rg->to = f; } } @@ -2454,6 +2453,9 @@ struct page *alloc_huge_page(struct vm_area_struct *vma, rsv_adjust = hugepage_subpool_put_pages(spool, 1); hugetlb_acct_memory(h, -rsv_adjust); + if (deferred_reserve) + hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h), + pages_per_huge_page(h), page); } return page; -- 2.25.4