From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Daniel Jordan Subject: [PATCH 5/5] kvm/book3s: use pinned_vm instead of locked_vm to account pinned pages Date: Mon, 11 Feb 2019 17:44:37 -0500 Message-Id: <20190211224437.25267-6-daniel.m.jordan@oracle.com> In-Reply-To: <20190211224437.25267-1-daniel.m.jordan@oracle.com> References: <20190211224437.25267-1-daniel.m.jordan@oracle.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: jgg@ziepe.ca Cc: akpm@linux-foundation.org, dave@stgolabs.net, jack@suse.cz, cl@linux.com, linux-mm@kvack.org, kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, alex.williamson@redhat.com, paulus@ozlabs.org, benh@kernel.crashing.org, mpe@ellerman.id.au, hao.wu@intel.com, atull@kernel.org, mdf@kernel.org, aik@ozlabs.ru, daniel.m.jordan@oracle.com List-ID: Memory used for TCE tables in kvm_vm_ioctl_create_spapr_tce is currently accounted to locked_vm because it stays resident and its allocation is directly triggered from userspace as explained in f8626985c7c2 ("KVM: PPC: Account TCE-containing pages in locked_vm"). However, since the memory comes straight from the page allocator (and to a lesser extent unreclaimable slab) and is effectively pinned, it should be accounted with pinned_vm (see bc3e53f682d9 ("mm: distinguish between mlocked and pinned pages")). pinned_vm recently became atomic and so no longer relies on mmap_sem held as writer: delete. Signed-off-by: Daniel Jordan --- arch/powerpc/kvm/book3s_64_vio.c | 35 ++++++++++++++------------------ 1 file changed, 15 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 532ab79734c7..2f8d7c051e4e 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -56,39 +56,34 @@ static unsigned long kvmppc_stt_pages(unsigned long tce_pages) return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; } -static long kvmppc_account_memlimit(unsigned long stt_pages, bool inc) +static long kvmppc_account_memlimit(unsigned long pages, bool inc) { long ret = 0; + s64 pinned_vm; if (!current || !current->mm) return ret; /* process exited */ - down_write(¤t->mm->mmap_sem); - if (inc) { - unsigned long locked, lock_limit; + unsigned long lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - locked = current->mm->locked_vm + stt_pages; - lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; - if (locked > lock_limit && !capable(CAP_IPC_LOCK)) + pinned_vm = atomic64_add_return(pages, ¤t->mm->pinned_vm); + if (pinned_vm > lock_limit && !capable(CAP_IPC_LOCK)) { ret = -ENOMEM; - else - current->mm->locked_vm += stt_pages; + atomic64_sub(pages, ¤t->mm->pinned_vm); + } } else { - if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm)) - stt_pages = current->mm->locked_vm; + pinned_vm = atomic64_read(¤t->mm->pinned_vm); + if (WARN_ON_ONCE(pages > pinned_vm)) + pages = pinned_vm; - current->mm->locked_vm -= stt_pages; + atomic64_sub(pages, ¤t->mm->pinned_vm); } - pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid, - inc ? '+' : '-', - stt_pages << PAGE_SHIFT, - current->mm->locked_vm << PAGE_SHIFT, - rlimit(RLIMIT_MEMLOCK), - ret ? " - exceeded" : ""); - - up_write(¤t->mm->mmap_sem); + pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%lu %ld/%lu%s\n", current->pid, + inc ? '+' : '-', pages << PAGE_SHIFT, + atomic64_read(¤t->mm->pinned_vm) << PAGE_SHIFT, + rlimit(RLIMIT_MEMLOCK), ret ? " - exceeded" : ""); return ret; } -- 2.20.1