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| author | Jason Xing <kernelxing@tencent.com> | 2025-06-12 14:11:57 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-07-09 22:57:51 -0700 |
| commit | 2489e958129ff7cbf26a34ee33cdc9ccbd68fe3c (patch) | |
| tree | a36e1e6b43ecad6ce55a8658f77c34376b527cb7 /kernel | |
| parent | squashfs: use folios in squashfs_bio_read_cached() (diff) | |
| download | linux-2489e958129ff7cbf26a34ee33cdc9ccbd68fe3c.tar.gz linux-2489e958129ff7cbf26a34ee33cdc9ccbd68fe3c.zip | |
relayfs: abolish prev_padding
Patch series "relayfs: misc changes", v5.
The series mostly focuses on the error counters which helps every user
debug their own kernel module.
This patch (of 5):
prev_padding represents the unused space of certain subbuffer. If the
content of a call of relay_write() exceeds the limit of the remainder of
this subbuffer, it will skip storing in the rest space and record the
start point as buf->prev_padding in relay_switch_subbuf(). Since the buf
is a per-cpu big buffer, the point of prev_padding as a global value for
the whole buffer instead of a single subbuffer (whose padding info is
stored in buf->padding[]) seems meaningless from the real use cases, so we
don't bother to record it any more.
Link: https://lkml.kernel.org/r/20250612061201.34272-1-kerneljasonxing@gmail.com
Link: https://lkml.kernel.org/r/20250612061201.34272-2-kerneljasonxing@gmail.com
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Yushan Zhou <katrinzhou@tencent.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/relay.c | 14 | ||||
| -rw-r--r-- | kernel/trace/blktrace.c | 2 |
2 files changed, 9 insertions, 7 deletions
diff --git a/kernel/relay.c b/kernel/relay.c index 3ee5b038d0d9..fc6ad76b789d 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -249,13 +249,13 @@ EXPORT_SYMBOL_GPL(relay_buf_full); */ static int relay_subbuf_start(struct rchan_buf *buf, void *subbuf, - void *prev_subbuf, size_t prev_padding) + void *prev_subbuf) { if (!buf->chan->cb->subbuf_start) return !relay_buf_full(buf); return buf->chan->cb->subbuf_start(buf, subbuf, - prev_subbuf, prev_padding); + prev_subbuf); } /** @@ -301,7 +301,7 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init) for (i = 0; i < buf->chan->n_subbufs; i++) buf->padding[i] = 0; - relay_subbuf_start(buf, buf->data, NULL, 0); + relay_subbuf_start(buf, buf->data, NULL); } /** @@ -554,9 +554,11 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) goto toobig; if (buf->offset != buf->chan->subbuf_size + 1) { - buf->prev_padding = buf->chan->subbuf_size - buf->offset; + size_t prev_padding; + + prev_padding = buf->chan->subbuf_size - buf->offset; old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; - buf->padding[old_subbuf] = buf->prev_padding; + buf->padding[old_subbuf] = prev_padding; buf->subbufs_produced++; if (buf->dentry) d_inode(buf->dentry)->i_size += @@ -581,7 +583,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length) new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs; new = buf->start + new_subbuf * buf->chan->subbuf_size; buf->offset = 0; - if (!relay_subbuf_start(buf, new, old, buf->prev_padding)) { + if (!relay_subbuf_start(buf, new, old)) { buf->offset = buf->chan->subbuf_size + 1; return 0; } diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 3f6a7bdc6edf..d3083c88474e 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -461,7 +461,7 @@ static const struct file_operations blk_msg_fops = { * the user space app in telling how many lost events there were. */ static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf, - void *prev_subbuf, size_t prev_padding) + void *prev_subbuf) { struct blk_trace *bt; |