diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2021-08-05 14:59:40 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-08-05 15:08:47 -0700 |
| commit | 0ca8d3ca4561535f97b31e7b8de569c69bc3b27b (patch) | |
| tree | fb452bc7d0fa536caea8b0a6eb00af1975ae5ba2 /fs/pipe.c | |
| parent | 23809a726c0d004b9d2474333181f8da07360469 (diff) | |
| parent | 902e7f373fff2476b53824264c12e4e76c7ec02a (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Build failure in drivers/net/wwan/mhi_wwan_mbim.c:
add missing parameter (0, assuming we don't want buffer pre-alloc).
Conflict in drivers/net/dsa/sja1105/sja1105_main.c between:
589918df9322 ("net: dsa: sja1105: be stateless with FDB entries on SJA1105P/Q/R/S/SJA1110 too")
0fac6aa098ed ("net: dsa: sja1105: delete the best_effort_vlan_filtering mode")
Follow the instructions from the commit message of the former commit
- removed the if conditions. When looking at commit 589918df9322 ("net:
dsa: sja1105: be stateless with FDB entries on SJA1105P/Q/R/S/SJA1110 too")
note that the mask_iotag fields get removed by the following patch.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'fs/pipe.c')
| -rw-r--r-- | fs/pipe.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index 9ef4231cce61..8e6ef62aeb1c 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -32,6 +32,21 @@ #include "internal.h" /* + * New pipe buffers will be restricted to this size while the user is exceeding + * their pipe buffer quota. The general pipe use case needs at least two + * buffers: one for data yet to be read, and one for new data. If this is less + * than two, then a write to a non-empty pipe may block even if the pipe is not + * full. This can occur with GNU make jobserver or similar uses of pipes as + * semaphores: multiple processes may be waiting to write tokens back to the + * pipe before reading tokens: https://lore.kernel.org/lkml/1628086770.5rn8p04n6j.none@localhost/. + * + * Users can reduce their pipe buffers with F_SETPIPE_SZ below this at their + * own risk, namely: pipe writes to non-full pipes may block until the pipe is + * emptied. + */ +#define PIPE_MIN_DEF_BUFFERS 2 + +/* * The max size that a non-root user is allowed to grow the pipe. Can * be set by root in /proc/sys/fs/pipe-max-size */ @@ -781,8 +796,8 @@ struct pipe_inode_info *alloc_pipe_info(void) user_bufs = account_pipe_buffers(user, 0, pipe_bufs); if (too_many_pipe_buffers_soft(user_bufs) && pipe_is_unprivileged_user()) { - user_bufs = account_pipe_buffers(user, pipe_bufs, 1); - pipe_bufs = 1; + user_bufs = account_pipe_buffers(user, pipe_bufs, PIPE_MIN_DEF_BUFFERS); + pipe_bufs = PIPE_MIN_DEF_BUFFERS; } if (too_many_pipe_buffers_hard(user_bufs) && pipe_is_unprivileged_user()) |