From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f199.google.com (mail-oi1-f199.google.com [209.85.167.199]) by kanga.kvack.org (Postfix) with ESMTP id 8D9958E0001 for ; Mon, 21 Jan 2019 12:42:49 -0500 (EST) Received: by mail-oi1-f199.google.com with SMTP id r131so9935097oia.7 for ; Mon, 21 Jan 2019 09:42:49 -0800 (PST) Received: from smtp2.provo.novell.com (smtp2.provo.novell.com. [137.65.250.81]) by mx.google.com with ESMTPS id x79si2933700oif.183.2019.01.21.09.42.47 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Jan 2019 09:42:48 -0800 (PST) From: Davidlohr Bueso Subject: [PATCH v2 -next 0/6] mm: make pinned_vm atomic and simplify users Date: Mon, 21 Jan 2019 09:42:14 -0800 Message-Id: <20190121174220.10583-1-dave@stgolabs.net> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: dledford@redhat.com, jgg@mellanox.com, jack@suse.de, ira.weiny@intel.com, linux-rdma@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, dave@stgolabs.net Changes from v1 (https://patchwork.kernel.org/cover/10764923/): - Converted pinned_vm to atomic64 instead of atomic_long such that infiniband need not worry about overflows. - Rebased patch 1 and added Ira's reviews as well as Parvi's review for patch 5 (thanks!). -------- Hi, The following patches aim to provide cleanups to users that pin pages (mostly infiniband) by converting the counter to atomic -- note that Daniel Jordan also has patches[1] for the locked_vm counterpart and vfio. Apart from removing a source of mmap_sem writer, we benefit in that we can get rid of a lot of code that defers work when the lock cannot be acquired, as well as drivers avoiding mmap_sem altogether by also converting gup to gup_fast() and letting the mm handle it. Users that do the gup_longterm() remain of course under at least reader mmap_sem. Everything has been compile-tested _only_ so I hope I didn't do anything too stupid. Please consider for v5.1. On a similar topic and potential follow up, it would be nice to resurrect Peter's VM_PINNED idea in that the broken semantics that occurred after bc3e53f682 ("mm: distinguish between mlocked and pinned pages") are still present. Also encapsulating internal mm logic via mm[un]pin() instead of drivers having to know about internals and playing nice with compaction are all wins. Thanks! [1] https://lkml.org/lkml/2018/11/5/854 Davidlohr Bueso (6): mm: make mm->pinned_vm an atomic64 counter mic/scif: do not use mmap_sem drivers/IB,qib: do not use mmap_sem drivers/IB,hfi1: do not se mmap_sem drivers/IB,usnic: reduce scope of mmap_sem drivers/IB,core: reduce scope of mmap_sem drivers/infiniband/core/umem.c | 47 +++----------------- drivers/infiniband/hw/hfi1/user_pages.c | 12 ++--- drivers/infiniband/hw/qib/qib_user_pages.c | 69 ++++++++++------------------- drivers/infiniband/hw/usnic/usnic_ib_main.c | 2 - drivers/infiniband/hw/usnic/usnic_uiom.c | 56 +++-------------------- drivers/infiniband/hw/usnic/usnic_uiom.h | 1 - drivers/misc/mic/scif/scif_rma.c | 38 +++++----------- fs/proc/task_mmu.c | 2 +- include/linux/mm_types.h | 2 +- kernel/events/core.c | 8 ++-- kernel/fork.c | 2 +- mm/debug.c | 3 +- 12 files changed, 57 insertions(+), 185 deletions(-) -- 2.16.4