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Wed, 01 Mar 2023 11:05:00 -0800 (PST) Date: Wed, 1 Mar 2023 11:04:57 -0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.0.rc0.216.gc4246ad0f0-goog Message-ID: <20230301190457.1498985-1-surenb@google.com> Subject: [PATCH 1/1] mm/nommu: remove unnecessary VMA locking From: Suren Baghdasaryan To: akpm@linux-foundation.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: michel@lespinasse.org, joelaf@google.com, songliubraving@fb.com, mhocko@suse.com, leewalsh@google.com, david@redhat.com, peterz@infradead.org, bigeasy@linutronix.de, peterx@redhat.com, dhowells@redhat.com, linux-mm@kvack.org, edumazet@google.com, jglisse@google.com, punit.agrawal@bytedance.com, Hyeonggon Yoo <42.hyeyoo@gmail.com>, will@kernel.org, arjunroy@google.com, chriscli@google.com, dave@stgolabs.net, minchan@google.com, x86@kernel.org, hughd@google.com, willy@infradead.org, gurua@google.com, mingo@redhat.com, linux-arm-kernel@lists.infradead.org, rientjes@google.com, axelrasmussen@google.com, kernel-team@android.com, michalechner92@googlemail.com, soheil@google.com, paulmck@kernel.org, jannh@google.com, liam.howlett@oracle.com, shakeelb@google.com, luto@kernel.org, gthelen@google.com, ldufour@linux.ibm.com, Suren Baghdasaryan , vbabka@suse.cz, posk@google.com, lstoakes@gmail.com, peterjung1337@gmail.com, linuxppc-dev@lists.ozlabs.org, kent.overstreet@lin ux.dev, linux-kernel@vger.kernel.org, hannes@cmpxchg.org, tatashin@google.com, mgorman@techsingularity.net, rppt@kernel.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Since CONFIG_PER_VMA_LOCK depends on CONFIG_MMU, the changes in nommu are not needed. Remove them. Fixes: bad94decd6a4 ("mm: write-lock VMAs before removing them from VMA tree") Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lore.kernel.org/all/Y%2F8CJQGNuMUTdLwP@localhost/ Signed-off-by: Suren Baghdasaryan Reviewed-by: David Hildenbrand --- Fix cleanly applies over mm-unstable, SHA in "Fixes" is from that tree. mm/nommu.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/mm/nommu.c b/mm/nommu.c index 2ab162d773e2..57ba243c6a37 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -588,7 +588,6 @@ static int delete_vma_from_mm(struct vm_area_struct *vma) current->pid); return -ENOMEM; } - vma_start_write(vma); cleanup_vma_from_mm(vma); /* remove from the MM's tree and list */ @@ -1520,10 +1519,6 @@ void exit_mmap(struct mm_struct *mm) */ mmap_write_lock(mm); for_each_vma(vmi, vma) { - /* - * No need to lock VMA because this is the only mm user and no - * page fault handled can race with it. - */ cleanup_vma_from_mm(vma); delete_vma(mm, vma); cond_resched();