diff options
| author | Wen Yang <wenyang.linux@foxmail.com> | 2024-01-15 23:27:00 +0800 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2024-01-23 17:56:29 +0100 |
| commit | bd46543d7f9a8b2c03420499b1885287e96aaf28 (patch) | |
| tree | 52a195002a8ac09a8a83840b0351fa4c176da5e1 | |
| parent | 3948abaa4e2be938ccdfc289385a27342fb13d43 (diff) | |
eventfd: move 'eventfd-count' printing out of spinlock
When printing eventfd->count, interrupts will be disabled and a spinlock
will be obtained, competing with eventfd_write(). By moving the
"eventfd-count" print out of the spinlock and merging multiple
seq_printf() into one, it could improve a bit, just like timerfd_show().
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Link: https://lore.kernel.org/r/tencent_B0B3D2BD9861FD009E03AB18A81783322709@qq.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Eric Biggers <ebiggers@google.com>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/eventfd.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/fs/eventfd.c b/fs/eventfd.c index 0252b71099fb..fc4d81090763 100644 --- a/fs/eventfd.c +++ b/fs/eventfd.c @@ -283,13 +283,18 @@ static ssize_t eventfd_write(struct file *file, const char __user *buf, size_t c static void eventfd_show_fdinfo(struct seq_file *m, struct file *f) { struct eventfd_ctx *ctx = f->private_data; + __u64 cnt; spin_lock_irq(&ctx->wqh.lock); - seq_printf(m, "eventfd-count: %16llx\n", - (unsigned long long)ctx->count); + cnt = ctx->count; spin_unlock_irq(&ctx->wqh.lock); - seq_printf(m, "eventfd-id: %d\n", ctx->id); - seq_printf(m, "eventfd-semaphore: %d\n", + + seq_printf(m, + "eventfd-count: %16llx\n" + "eventfd-id: %d\n" + "eventfd-semaphore: %d\n", + cnt, + ctx->id, !!(ctx->flags & EFD_SEMAPHORE)); } #endif |