From: Peter Xu <peterx@redhat.com>
To: Axel Rasmussen <axelrasmussen@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Hugh Dickins <hughd@google.com>,
Jerome Glisse <jglisse@redhat.com>, Joe Perches <joe@perches.com>,
Lokesh Gidra <lokeshgidra@google.com>,
Mike Kravetz <mike.kravetz@oracle.com>,
Mike Rapoport <rppt@linux.vnet.ibm.com>, Shaohua Li <shli@fb.com>,
Shuah Khan <shuah@kernel.org>,
Stephen Rothwell <sfr@canb.auug.org.au>,
Wang Qing <wangqing@vivo.com>,
linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-mm@kvack.org, Brian Geffon <bgeffon@google.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Mina Almasry <almasrymina@google.com>,
Oliver Upton <oupton@google.com>
Subject: Re: [PATCH v2 6/9] userfaultfd/selftests: create alias mappings in the shmem test
Date: Tue, 13 Apr 2021 16:17:50 -0400 [thread overview]
Message-ID: <20210413201750.GF4440@xz-x1> (raw)
In-Reply-To: <20210413051721.2896915-7-axelrasmussen@google.com>
On Mon, Apr 12, 2021 at 10:17:18PM -0700, Axel Rasmussen wrote:
> static void shmem_allocate_area(void **alloc_area)
> {
> - unsigned long offset =
> - alloc_area == (void **)&area_src ? 0 : nr_pages * page_size;
> + void *area_alias = NULL;
> + bool is_src = alloc_area == (void **)&area_src;
> + unsigned long offset = is_src ? 0 : nr_pages * page_size;
>
> *alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
> MAP_SHARED, shm_fd, offset);
> if (*alloc_area == MAP_FAILED)
> err("mmap of memfd failed");
> +
> + area_alias = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
> + MAP_SHARED, shm_fd, offset);
> + if (area_alias == MAP_FAILED)
> + err("mmap of memfd alias failed");
> +
> + if (is_src)
> + area_src_alias = area_alias;
> + else
> + area_dst_alias = area_alias;
> +}
It would be nice if shmem_allocate_area() could merge with
hugetlb_allocate_area() somehow, but not that urgent.
Reviewed-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
next prev parent reply other threads:[~2021-04-13 20:17 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 5:17 [PATCH v2 0/9] userfaultfd: add minor fault handling for shmem Axel Rasmussen
2021-04-13 5:17 ` [PATCH v2 1/9] userfaultfd/hugetlbfs: avoid including userfaultfd_k.h in hugetlb.h Axel Rasmussen
2021-04-14 6:43 ` Hugh Dickins
2021-04-13 5:17 ` [PATCH v2 2/9] userfaultfd/shmem: combine shmem_{mcopy_atomic,mfill_zeropage}_pte Axel Rasmussen
2021-04-14 6:51 ` Hugh Dickins
2021-04-13 5:17 ` [PATCH v2 3/9] userfaultfd/shmem: support minor fault registration for shmem Axel Rasmussen
2021-04-13 20:43 ` Peter Xu
2021-04-14 7:36 ` Hugh Dickins
2021-04-14 18:51 ` Peter Xu
2021-04-13 5:17 ` [PATCH v2 4/9] userfaultfd/shmem: support UFFDIO_CONTINUE " Axel Rasmussen
2021-04-16 23:47 ` Hugh Dickins
2021-04-20 18:05 ` Axel Rasmussen
2021-04-13 5:17 ` [PATCH v2 5/9] userfaultfd/selftests: use memfd_create for shmem test type Axel Rasmussen
2021-04-13 20:16 ` Peter Xu
2021-04-13 5:17 ` [PATCH v2 6/9] userfaultfd/selftests: create alias mappings in the shmem test Axel Rasmussen
2021-04-13 20:17 ` Peter Xu [this message]
2021-04-13 5:17 ` [PATCH v2 7/9] userfaultfd/selftests: reinitialize test context in each test Axel Rasmussen
2021-04-13 20:15 ` Peter Xu
2021-04-15 18:03 ` Axel Rasmussen
2021-04-13 5:17 ` [PATCH v2 8/9] userfaultfd/selftests: exercise minor fault handling shmem support Axel Rasmussen
2021-04-13 5:17 ` [PATCH v2 9/9] userfaultfd/shmem: modify shmem_mcopy_atomic_pte to use install_ptes Axel Rasmussen
2021-04-17 0:34 ` Hugh Dickins
2021-04-20 18:43 ` Axel Rasmussen
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