From: Wei Yang <richard.weiyang@linux.alibaba.com>
To: rostedt@goodmis.org, mingo@redhat.com
Cc: linux-kernel@vger.kernel.org,
Wei Yang <richard.weiyang@linux.alibaba.com>
Subject: [PATCH 2/6] ftrace: use fls() to get the bits for dup_hash()
Date: Mon, 31 Aug 2020 11:11:00 +0800 [thread overview]
Message-ID: <20200831031104.23322-3-richard.weiyang@linux.alibaba.com> (raw)
In-Reply-To: <20200831031104.23322-1-richard.weiyang@linux.alibaba.com>
The effect here is to get the number of bits, lets use fls() to do
this job.
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
---
kernel/trace/ftrace.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 12cb535769bc..9021e16fa079 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1370,8 +1370,9 @@ static struct ftrace_hash *dup_hash(struct ftrace_hash *src, int size)
/*
* Make the hash size about 1/2 the # found
*/
- for (size /= 2; size; size >>= 1)
- bits++;
+ bits = fls(size);
+ if (bits)
+ bits--;
/* Don't allocate too much */
if (bits > FTRACE_HASH_MAX_BITS)
--
2.20.1 (Apple Git-117)
next prev parent reply other threads:[~2020-08-31 3:11 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-31 3:10 [PATCH 0/6] ftrace: trivial cleanup Wei Yang
2020-08-31 3:10 ` [PATCH 1/6] ftrace: define seq_file only for FMODE_READ Wei Yang
2020-10-06 14:36 ` Steven Rostedt
2020-10-08 3:34 ` Wei Yang
2020-08-31 3:11 ` Wei Yang [this message]
2020-08-31 3:11 ` [PATCH 3/6] ftrace: simplify the dyn_ftrace->flags macro Wei Yang
2020-08-31 3:11 ` [PATCH 4/6] ftrace: simplify the calculation of page number for ftrace_page->records Wei Yang
2020-08-31 3:11 ` [PATCH 5/6] ftrace: replace do_for_each_ftrace_rec() with for_ftrace_rec_iter() Wei Yang
2020-10-06 14:42 ` Steven Rostedt
2020-10-08 3:34 ` Wei Yang
2020-08-31 3:11 ` [PATCH 6/6] ftrace: ftrace_global_list is renamed to ftrace_ops_list Wei Yang
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