On Thu, Jun 23, 2022 at 03:06:06PM -0700, Kalesh Singh wrote:
To be able to account the amount of memory a process is keeping pinned by open file descriptors add a 'size' field to fdinfo output.
dmabufs fds already expose a 'size' field for this reason, remove this and make it a common field for all fds. This allows tracking of other types of memory (e.g. memfd and ashmem in Android).
Signed-off-by: Kalesh Singh kaleshsingh@google.com Reviewed-by: Christian König christian.koenig@amd.com
Changes in v2:
- Add Christian's Reviewed-by
Changes from rfc:
- Split adding 'size' and 'path' into a separate patches, per Christian
- Split fdinfo seq_printf into separate lines, per Christian
- Fix indentation (use tabs) in documentaion, per Randy
Documentation/filesystems/proc.rst | 12 ++++++++++-- drivers/dma-buf/dma-buf.c | 1 - fs/proc/fd.c | 9 +++++---- 3 files changed, 15 insertions(+), 7 deletions(-)
...
diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 913bef0d2a36..464bc3f55759 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -54,10 +54,11 @@ static int seq_show(struct seq_file *m, void *v) if (ret) return ret;
- seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\nino:\t%lu\n",
(long long)file->f_pos, f_flags,real_mount(file->f_path.mnt)->mnt_id,file_inode(file)->i_ino);
- seq_printf(m, "pos:\t%lli\n", (long long)file->f_pos);
- seq_printf(m, "flags:\t0%o\n", f_flags);
- seq_printf(m, "mnt_id:\t%i\n", real_mount(file->f_path.mnt)->mnt_id);
- seq_printf(m, "ino:\t%lu\n", file_inode(file)->i_ino);
- seq_printf(m, "size:\t%lli\n", (long long)file_inode(file)->i_size);
Hi Kalesh,
Any reason not to use i_size_read() here?
Also not sure if it matters that much for your use case, but something worth noting at least with shmem is that one can do something like:
# cat /proc/meminfo | grep Shmem: Shmem: 764 kB # xfs_io -fc "falloc -k 0 10m" ./file # ls -alh file -rw-------. 1 root root 0 Jun 28 07:22 file # stat file File: file Size: 0 Blocks: 20480 IO Block: 4096 regular empty file # cat /proc/meminfo | grep Shmem: Shmem: 11004 kB
... where the resulting memory usage isn't reflected in i_size (but is is in i_blocks/bytes).
Brian
/* show_fd_locks() never deferences files so a stale value is safe */ show_fd_locks(m, file, files); -- 2.37.0.rc0.161.g10f37bed90-goog