With 4k guest and 64k host, on aarch64(Ampere's Altra Max CPU) hit Call trace: Steps: 1) System setup hugepages on host. # echo 50 > /proc/sys/vm/nr_hugepages 2) Mount this hugepage to /mnt/kvm_hugepage. # mount -t hugetlbfs -o pagesize=524288K none /mnt/kvm_hugepage 3) HugePages didn't leak when using non-existent mem-path. # cd /home/kar/workspace/avocado-vt/virttest; mkdir -p /mnt/tmp 4) Run memory heavy stress inside guest. # /usr/libexec/qemu-kvm \ ... -m 25600 \ -object '{"size": 26843545600, "mem-path": "/mnt/tmp", "id": "mem-machine_mem", "qom-type": "memory-backend-file"}' \ -smp 60,maxcpus=60,cores=30,threads=1,clusters=1,sockets=2 \ login guest: # nohup stress --vm 50 --vm-bytes 256M --timeout 30s > /dev/null & ------> hit Call trace
On guest kernel: 2023-09-18 07:54:03: [ 76.592706] CPU: 23 PID: 254 Comm: kworker/23:1 Kdump: loaded Not tainted 6.6.0-rc2-zhenyzha_4k+ #3 2023-09-18 07:54:03: [ 76.593782] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230524-3.el9 05/24/2023 2023-09-18 07:54:03: [ 76.594641] Workqueue: rcu_gp wait_rcu_exp_gp 2023-09-18 07:54:03: [ 76.595248] pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) 2023-09-18 07:54:03: [ 76.596025] pc : smp_call_function_single+0xe4/0x1e8 2023-09-18 07:54:03: [ 76.596833] lr : __sync_rcu_exp_select_node_cpus+0x27c/0x428 2023-09-18 07:54:03: [ 76.597534] sp : ffff800084a0bc60 2023-09-18 07:54:03: [ 76.598078] x29: ffff800084a0bc60 x28: ffff0003fdad9440 x27: 0000000000000001 2023-09-18 07:54:03: [ 76.598874] x26: ffff800081a541b0 x25: ffff800081e0af40 x24: ffff0000c425ed80 2023-09-18 07:54:03: [ 76.599817] x23: 0000000000000004 x22: ffff800081532fa0 x21: 0000000000000ffe 2023-09-18 07:54:03: [ 76.600621] x20: ffff800081537440 x19: ffff800084a0bca0 x18: 0000000000000001 2023-09-18 07:54:03: [ 76.601420] x17: 0000000000000000 x16: ffff800080f352e8 x15: 0000ffff97d02fff 2023-09-18 07:54:03: [ 76.602212] x14: 0000000000000000 x13: 0000000000000030 x12: 0101010101010101 2023-09-18 07:54:03: [ 76.603158] x11: ffff800081532fa0 x10: 0000000000000001 x9 : ffff80008014c714 2023-09-18 07:54:03: [ 76.603963] x8 : ffff800081e03130 x7 : ffff800081521008 x6 : ffff80008014e070 2023-09-18 07:54:03: [ 76.604759] x5 : 0000000000000000 x4 : ffff0003fda34c88 x3 : 0000000000000001 2023-09-18 07:54:03: [ 76.605703] x2 : 0000000000000000 x1 : ffff0003fda34c80 x0 : 000000000000001c 2023-09-18 07:54:03: [ 76.606507] Call trace: 2023-09-18 07:54:03: [ 76.606990] smp_call_function_single+0xe4/0x1e8 2023-09-18 07:54:03: [ 76.607617] __sync_rcu_exp_select_node_cpus+0x27c/0x428 2023-09-18 07:54:03: [ 76.608290] sync_rcu_exp_select_cpus+0x164/0x2e0 2023-09-18 07:54:03: [ 76.608963] wait_rcu_exp_gp+0x1c/0x38 2023-09-18 07:54:03: [ 76.609563] process_one_work+0x174/0x3c8 2023-09-18 07:54:03: [ 76.610181] worker_thread+0x2c8/0x3e0 2023-09-18 07:54:03: [ 76.610776] kthread+0x100/0x110 2023-09-18 07:54:03: [ 76.611330] ret_from_fork+0x10/0x20 2023-09-18 07:54:15: [ 88.396191] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: 2023-09-18 07:54:15: [ 88.397195] rcu: 11-...0: (18 ticks this GP) idle=79ec/1/0x4000000000000000 softirq=577/579 fqs=1215 2023-09-18 07:54:15: [ 88.398244] rcu: 25-...0: (1 GPs behind) idle=599c/1/0x4000000000000000 softirq=300/301 fqs=1215 2023-09-18 07:54:15: [ 88.399254] rcu: 33-...0: (36 ticks this GP) idle=e454/1/0x4000000000000000 softirq=717/719 fqs=1216 2023-09-18 07:54:15: [ 88.400275] rcu: (detected by 19, t=6006 jiffies, g=1173, q=61327 ncpus=38) 2023-09-18 07:54:15: [ 88.401135] Task dump for CPU 11: 2023-09-18 07:54:15: [ 88.401711] task:stress state:R running task stack:0 pid:3182 ppid:3178 flags:0x00000202 2023-09-18 07:54:15: [ 88.402794] Call trace: 2023-09-18 07:54:15: [ 88.403312] __switch_to+0xc8/0x110 2023-09-18 07:54:15: [ 88.403915] do_page_fault+0x198/0x4e0 2023-09-18 07:54:15: [ 88.404533] do_translation_fault+0x38/0x68 2023-09-18 07:54:15: [ 88.405169] do_mem_abort+0x48/0xa0 2023-09-18 07:54:15: [ 88.405771] el0_da+0x4c/0x180 2023-09-18 07:54:15: [ 88.406337] el0t_64_sync_handler+0xdc/0x150 2023-09-18 07:54:15: [ 88.406991] el0t_64_sync+0x17c/0x180 2023-09-18 07:54:15: [ 88.407601] Task dump for CPU 25: 2023-09-18 07:54:15: [ 88.408182] task:stress state:R running task stack:0 pid:3200 ppid:3178 flags:0x00000203 2023-09-18 07:54:15: [ 88.409258] Call trace: 2023-09-18 07:54:15: [ 88.409769] __switch_to+0xc8/0x110 2023-09-18 07:54:15: [ 88.410339] 0x440dc0 2023-09-18 07:54:15: [ 88.410816] Task dump for CPU 33: 2023-09-18 07:54:15: [ 88.411362] task:stress state:R running task stack:0 pid:3191 ppid:3178 flags:0x00000203 2023-09-18 07:54:15: [ 88.412403] Call trace: 2023-09-18 07:54:15: [ 88.412866] __switch_to+0xc8/0x110 2023-09-18 07:54:15: [ 88.413405] __memcg_kmem_charge_page+0x270/0x2c0 2023-09-18 07:54:15: [ 88.414033] __alloc_pages+0x100/0x278 2023-09-18 07:54:15: [ 88.414585] memcg_stock+0x0/0x58
On host kernel: 173242 Sep 18 08:57:51 virt-mtsnow-02 kernel: ------------[ cut here ]------------ 173243 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 52 kernel messages 173244 Sep 18 08:57:51 virt-mtsnow-02 kernel: do_cow_fault+0xf0/0x300 173245 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 162 kernel messages 173246 Sep 18 08:57:51 virt-mtsnow-02 kernel: CPU: 14 PID: 11294 Comm: qemu-kvm Tainted: G W 6.6.0-rc2-zhenyzha-64k+ #1 173247 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 226 kernel messages 173248 Sep 18 08:57:51 virt-mtsnow-02 kernel: x21: 0000000000000000 173249 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 120 kernel messages 173250 Sep 18 08:57:51 virt-mtsnow-02 kernel: __do_fault+0x40/0x210 173251 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 39 kernel messages 173252 Sep 18 08:57:51 virt-mtsnow-02 kernel: do_el0_svc+0xb4/0xd0 173253 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 325 kernel messages 173254 Sep 18 08:57:51 virt-mtsnow-02 kernel: get_user_pages_unlocked+0xc4/0x3b8 173255 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 255 kernel messages 173256 Sep 18 08:57:51 virt-mtsnow-02 kernel: pci_hyperv_intf i2c_designware_core 173257 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 87 kernel messages 173258 Sep 18 08:57:51 virt-mtsnow-02 kernel: xfs_filemap_fault+0x54/0x68 [xfs] 173259 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 248 kernel messages 173260 Sep 18 08:57:51 virt-mtsnow-02 kernel: pci_hyperv_intf 173261 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 69 kernel messages 173262 Sep 18 08:57:51 virt-mtsnow-02 kernel: Hardware name: GIGABYTE R152-P31-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021 173263 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 297 kernel messages 173264 Sep 18 08:57:51 virt-mtsnow-02 kernel: __filemap_add_folio+0x33c/0x4e0 173265 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 12 kernel messages 173266 Sep 18 08:57:51 virt-mtsnow-02 kernel: x26: 0000000000000001 173267 Sep 18 08:57:51 virt-mtsnow-02 systemd-journald[15184]: Missed 74 kernel messages
[ 5456.588346] ------------[ cut here ]------------ [ 5456.588358] x10: 000000000000000a [ 5456.588365] dm_mod [ 5456.588372] nft_compat [ 5456.588374] Hardware name: GIGABYTE R152-P31-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021 [ 5456.588417] fat [ 5456.588421] x16: 000000009872d4d0 [ 5456.588430] ipmi_msghandler arm_cmn [ 5456.588439] x10: 000000000000000a [ 5456.588414] __xfs_filemap_fault+0x60/0x3c0 [xfs] [ 5456.588454] x5 : 0000000000000028 [ 5456.588460] nvme_core [ 5456.588474] pci_hyperv_intf [ 5456.588482] ------------[ cut here ]------------ [ 5456.588488] page_cache_async_ra+0x64/0xa8 [ 5456.588491] filemap_fault+0x238/0xaa8 [ 5456.588506] nf_defrag_ipv4 nf_tables [ 5456.588514] nfs_acl [ 5456.588518] x22: ffffffc202880000 [ 5456.588525] netfs [ 5456.588527] stp
[ 5456.588539] acpi_ipmi [ 5456.588546] x10: 000000000000000a [ 5456.588554] x7 : ffff07ffa0a67210 [ 5456.588562] get_user_pages_unlocked+0xc4/0x3b8 [ 5456.588567] __gfn_to_pfn_memslot+0xa4/0xf8 [ 5456.588575] xas_split_alloc+0xf8/0x128 [ 5456.588581] sha1_ce [ 5456.588588] i2c_algo_bit [ 5456.588592] page_cache_async_ra+0x64/0xa8
Using @gshan@redhat.com 's patch:KVM: arm64: Fix soft-lockup on relaxing PTE permission Still hit Call trace: 2023-09-18 10:56:20: [ 57.494201] watchdog: BUG: soft lockup - CPU#58 stuck for 22s! [gsd-power:4858] 2023-09-18 10:56:20: [ 57.495674] Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill ip_set nf_tables nfnetlink qrtr vfat fat fuse xfs libcrc32c virtio_gpu virtio_dma_buf drm_shmem_helper nvme_tcp drm_kms_helper nvme_fabrics nvme_core nvme_common sg drm crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce virtio_net net_failover virtio_scsi failover virtio_mmio dm_multipath dm_mirror dm_region_hash dm_log dm_mod be2iscsi cxgb4i cxgb4 tls libcxgbi libcxgb qla4xxx iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi 2023-09-18 10:56:20: [ 57.501871] CPU: 58 PID: 4858 Comm: gsd-power Kdump: loaded Not tainted 6.6.0-rc2-zhenyzha_4k+ #3 2023-09-18 10:56:20: [ 57.502719] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230524-3.el9 05/24/2023 2023-09-18 10:56:20: [ 57.503540] pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) 2023-09-18 10:56:20: [ 57.504612] pc : smp_call_function_many_cond+0x16c/0x618 2023-09-18 10:56:20: [ 57.505425] lr : smp_call_function_many_cond+0x188/0x618 2023-09-18 10:56:20: [ 57.505974] sp : ffff8000870f38f0 2023-09-18 10:56:20: [ 57.506370] x29: ffff8000870f38f0 x28: 000000000000003c x27: ffff00063c5dcaa0 2023-09-18 10:56:20: [ 57.507041] x26: 000000000000003c x25: 000000000000003b x24: ffff00063c5b6848 2023-09-18 10:56:20: [ 57.507812] x23: 0000000000000000 x22: ffff00063c5b6848 x21: ffff800081a541b0 2023-09-18 10:56:20: [ 57.508513] x20: ffff00063c5b6840 x19: ffff800081a4f840 x18: 0000000000000014 2023-09-18 10:56:20: [ 57.509247] x17: 00000000fd875552 x16: 0000000044ca0210 x15: 000000005df1120b 2023-09-18 10:56:20: [ 57.509947] x14: 00000000ac15cb21 x13: 00000000b7ff1817 x12: 0000000006d3918c 2023-09-18 10:56:20: [ 57.510645] x11: 00000000ba65fdab x10: 00000000f60c2b88 x9 : ffff80008061a9dc 2023-09-18 10:56:20: [ 57.511264] x8 : ffff00063c5b6a50 x7 : 0000000000000000 x6 : 0000000001000000 2023-09-18 10:56:20: [ 57.511817] x5 : 000000000000003c x4 : 0000000000000007 x3 : ffff00063bf28aa8 2023-09-18 10:56:20: [ 57.512415] x2 : 0000000000000000 x1 : 0000000000000011 x0 : 0000000000000007 2023-09-18 10:56:20: [ 57.513092] Call trace: 2023-09-18 10:56:20: [ 57.515105] smp_call_function_many_cond+0x16c/0x618 2023-09-18 10:56:20: [ 57.515684] kick_all_cpus_sync+0x48/0x80 2023-09-18 10:56:20: [ 57.516039] flush_icache_range+0x40/0x60 2023-09-18 10:56:20: [ 57.516413] bpf_int_jit_compile+0x1ac/0x5f8 2023-09-18 10:56:20: [ 57.516821] bpf_prog_select_runtime+0xd4/0x110 2023-09-18 10:56:20: [ 57.517279] bpf_prepare_filter+0x1e8/0x220 2023-09-18 10:56:20: [ 57.517727] __get_filter+0xdc/0x180 2023-09-18 10:56:20: [ 57.518231] sk_attach_filter+0x1c/0xb0 2023-09-18 10:56:20: [ 57.518605] sk_setsockopt+0x9dc/0x1230 2023-09-18 10:56:20: [ 57.518909] sock_setsockopt+0x18/0x28 2023-09-18 10:56:20: [ 57.519177] __sys_setsockopt+0x164/0x190 2023-09-18 10:56:20: [ 57.519501] __arm64_sys_setsockopt+0x2c/0x40 2023-09-18 10:56:20: [ 57.519911] invoke_syscall.constprop.0+0x7c/0xd0 2023-09-18 10:56:20: [ 57.520345] do_el0_svc+0xb4/0xd0 2023-09-18 10:56:20: [ 57.520670] el0_svc+0x50/0x228 2023-09-18 10:56:20: [ 57.521331] el0t_64_sync_handler+0x134/0x150 2023-09-18 10:56:20: [ 57.521758] el0t_64_sync+0x17c/0x180 2023-09-18 10:56:23: [ 60.724199] watchdog: BUG: soft lockup - CPU#28 stuck for 26s! [(fwupd):5108]
[ 6253.928601] CPU: 64 PID: 18885 Comm: qemu-kvm Kdump: loaded Tainted: G W 6.6.0-rc1-zhenyzha_64k+ #2 [ 6253.939021] Hardware name: GIGABYTE R152-P31-00/MP32-AR1-00, BIOS F31n (SCP: 2.10.20220810) 09/30/2022 [ 6253.948312] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 6253.955262] pc : xas_split_alloc+0xf8/0x128 [ 6253.959432] lr : __filemap_add_folio+0x33c/0x4e0 [ 6253.964037] sp : ffff80008b10f210 [ 6253.967338] x29: ffff80008b10f210 x28: ffffba8c43708c00 x27: 0000000000000001 [ 6253.974461] x26: 0000000000000001 x25: ffffffffffffc005 x24: 0000000000000000 [ 6253.981583] x23: ffff80008b10f2c0 x22: 00000a36da000101 x21: 0000000000000000 [ 6253.988706] x20: ffffffc203be2a00 x19: 000000000000000d x18: 0000000000000014 [ 6253.995828] x17: 00000000be237f61 x16: 000000001baa68cc x15: ffffba8c429a5944 [ 6254.002950] x14: ffffba8c429b57bc x13: ffffba8c429a5944 x12: ffffba8c429b57bc [ 6254.010073] x11: ffffba8c4297160c x10: ffffba8c4365d414 x9 : ffffba8c4365857c [ 6254.017195] x8 : ffff80008b10f210 x7 : ffff07ffa1304900 x6 : ffff80008b10f210 [ 6254.024317] x5 : 000000000000000e x4 : 0000000000000000 x3 : 0000000000012c40 [ 6254.031439] x2 : 000000000000000d x1 : 000000000000000c x0 : 0000000000000000 [ 6254.038562] Call trace: [ 6254.040995] xas_split_alloc+0xf8/0x128 [ 6254.044818] __filemap_add_folio+0x33c/0x4e0 [ 6254.049076] filemap_add_folio+0x48/0xd0 [ 6254.052986] page_cache_ra_unbounded+0xf0/0x1f0 [ 6254.057504] page_cache_ra_order+0x8c/0x310 [ 6254.061675] filemap_fault+0x67c/0xaa8 [ 6254.065412] __xfs_filemap_fault+0x60/0x3c0 [xfs] [ 6254.070163] xfs_filemap_fault+0x54/0x68 [xfs] [ 6254.074651] __do_fault+0x40/0x210 [ 6254.078040] do_cow_fault+0xf0/0x300 [ 6254.081602] do_pte_missing+0x140/0x238 [ 6254.085426] handle_pte_fault+0x100/0x160 [ 6254.089423] __handle_mm_fault+0x100/0x310 [ 6254.093506] handle_mm_fault+0x6c/0x270 [ 6254.097330] faultin_page+0x70/0x128 [ 6254.100893] __get_user_pages+0xc8/0x2d8 [ 6254.104802] get_user_pages_unlocked+0xc4/0x3b8 [ 6254.109320] hva_to_pfn+0xf8/0x468 [ 6254.112709] __gfn_to_pfn_memslot+0xa4/0xf8 [ 6254.116879] user_mem_abort+0x174/0x7e8 [ 6254.120702] kvm_handle_guest_abort+0x2dc/0x450 [ 6254.125220] handle_exit+0x70/0x1c8 [ 6254.128696] kvm_arch_vcpu_ioctl_run+0x224/0x5b8 [ 6254.133300] kvm_vcpu_ioctl+0x28c/0x9d0 [ 6254.137123] __arm64_sys_ioctl+0xa8/0xf0 [ 6254.141033] invoke_syscall.constprop.0+0x7c/0xd0 [ 6254.145725] do_el0_svc+0xb4/0xd0 [ 6254.149028] el0_svc+0x50/0x228 [ 6254.152157] el0t_64_sync_handler+0x134/0x150 [ 6254.156501] el0t_64_sync+0x17c/0x180 [ 6254.160151] ---[ end trace 0000000000000000 ]--- [ 6254.164766] ------------[ cut here ]------------ [ 6254.169370] WARNING: CPU: 64 PID: 18885 at lib/xarray.c:1010 xas_split_alloc+0xf8/0x128 [ 6254.177361] Modules linked in: loop isofs cdrom vhost_net vhost vhost_iotlb tap tun bluetooth tls nfsv3 rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache netfs rpcrdma rdma_cm iw_cm ib_cm ib_core xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink bridge stp llc rfkill vfat fat ast drm_shmem_helper drm_kms_helper acpi_ipmi ipmi_ssif arm_spe_pmu ipmi_devintf ipmi_msghandler arm_cmn arm_dmc620_pmu arm_dsu_pmu cppc_cpufreq drm fuse nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c crct10dif_ce ghash_ce igb sha2_ce sha256_arm64 sha1_ce sbsa_gwdt i2c_designware_platform i2c_algo_bit i2c_designware_core xgene_hwmon sg dm_mirror dm_region_hash dm_log dm_mod
Tested-by: Zhenyu Zhang zhenyzha@redhat.com
On Mon, Sep 4, 2023 at 1:20 AM Joel Fernandes (Google) joel@joelfernandes.org wrote:
Hello!
Here is v6 of the mremap start address optimization / fix for exec warning. Should be hopefully final now and only 2/7 and 6/7 need a tag. Thanks a lot to Lorenzo and Linus for the detailed reviews.
Description of patches
These patches optimizes the start addresses in move_page_tables() and tests the changes. It addresses a warning [1] that occurs due to a downward, overlapping move on a mutually-aligned offset within a PMD during exec. By initiating the copy process at the PMD level when such alignment is present, we can prevent this warning and speed up the copying process at the same time. Linus Torvalds suggested this idea. Check the individual patches for more details. [1] https://lore.kernel.org/all/ZB2GTBD%2FLWTrkOiO@dhcp22.suse.cz/
History of patches: v5->v6:
- Reworking the stack case a bit more and tested it (should be final now).
- Other small nits.
v4->v5:
- Rebased on mainline.
- Several improvement suggestions from Lorenzo.
v3->v4:
Care to be taken to move purely within a VMA, in other words this check in call_align_down(): if (vma->vm_start != addr_masked) return false;
As an example of why this is needed: Consider the following range which is 2MB aligned and is a part of a larger 10MB range which is not shown. Each character is 256KB below making the source and destination 2MB each. The lower case letters are moved (s to d) and the upper case letters are not moved.
|DDDDddddSSSSssss|
If we align down 'ssss' to start from the 'SSSS', we will end up destroying SSSS. The above if statement prevents that and I verified it.
I also added a test for this in the last patch.
Handle the stack case separately. We do not care about #1 for stack movement because the 'SSSS' does not matter during this move. Further we need to do this to prevent the stack move warning.
if (!for_stack && vma->vm_start <= addr_masked) return false;
v2->v3:
- Masked address was stored in int, fixed it to unsigned long to avoid truncation.
- We now handle moves happening purely within a VMA, a new test is added to handle this.
- More code comments.
v1->v2:
- Trigger the optimization for mremaps smaller than a PMD. I tested by tracing
that it works correctly.
- Fix issue with bogus return value found by Linus if we broke out of the
above loop for the first PMD itself.
v1: Initial RFC.
Joel Fernandes (1): selftests: mm: Add a test for moving from an offset from start of mapping
Joel Fernandes (Google) (6): mm/mremap: Optimize the start addresses in move_page_tables() mm/mremap: Allow moves within the same VMA for stack moves selftests: mm: Fix failure case when new remap region was not found selftests: mm: Add a test for mutually aligned moves > PMD size selftests: mm: Add a test for remapping to area immediately after existing mapping selftests: mm: Add a test for remapping within a range
fs/exec.c | 2 +- include/linux/mm.h | 2 +- mm/mremap.c | 73 +++++- tools/testing/selftests/mm/mremap_test.c | 301 +++++++++++++++++++---- 4 files changed, 329 insertions(+), 49 deletions(-)
-- 2.42.0.283.g2d96d420d3-goog