From: Levi Yun <ppbuk5246@gmail.com>
To: akpm@linux-foundation.org, yury.norov@gmail.com,
andriy.shevchenko@linux.intel.com,
richard.weiyang@linux.alibaba.com, christian.brauner@ubuntu.com,
arnd@arndb.de, jpoimboe@redhat.com, changbin.du@intel.com,
rdunlap@infradead.org, masahiroy@kernel.org,
gregkh@linuxfoundation.org, peterz@infradead.org,
peter.enderborg@sony.com, krzk@kernel.org,
brendanhiggins@google.com, keescook@chromium.org,
broonie@kernel.org, matti.vaittinen@fi.rohmeurope.com,
mhiramat@kernel.org, jpa@git.mail.kapsi.fi,
nivedita@alum.mit.edu, glider@google.com, orson.zhai@unisoc.com,
takahiro.akashi@linaro.org, clm@fb.com, josef@toxicpanda.com,
dsterba@suse.com, dushistov@mail.ru
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-btrfs@vger.kernel.org
Subject: [PATCH v2 5/8] lib/find_bit_bench.c: Add find_last_zero_bit.
Date: Sun, 6 Dec 2020 15:49:05 +0900 [thread overview]
Message-ID: <20201206064905.GA6183@ubuntu> (raw)
Add bench test of find_last_zero_bit.
Also, this patch fix the unmatched iterations value with
find_next_bit and find_last_bit which happen when
the last bit set or not,
Let suppose, 4096 bitmap size and 4095 bit is set only.
In this case former find_next_bit returns iterations count as 0.
But find_last_bit returns it as 1.
This unmatched return value makes some confusion.
So we fix it.
Signed-off-by: Levi Yun <ppbuk5246@gmail.com>
---
lib/find_bit_benchmark.c | 51 +++++++++++++++++++++++++++++-----------
1 file changed, 37 insertions(+), 14 deletions(-)
diff --git a/lib/find_bit_benchmark.c b/lib/find_bit_benchmark.c
index 5637c5711db9..007371169008 100644
--- a/lib/find_bit_benchmark.c
+++ b/lib/find_bit_benchmark.c
@@ -35,14 +35,14 @@ static DECLARE_BITMAP(bitmap2, BITMAP_LEN) __initdata;
*/
static int __init test_find_first_bit(void *bitmap, unsigned long len)
{
- unsigned long i, cnt;
+ unsigned long i = 0, cnt = 0;
ktime_t time;
time = ktime_get();
- for (cnt = i = 0; i < len; cnt++) {
+ do {
i = find_first_bit(bitmap, len);
__clear_bit(i, bitmap);
- }
+ } while (i++ < len && ++cnt);
time = ktime_get() - time;
pr_err("find_first_bit: %18llu ns, %6ld iterations\n", time, cnt);
@@ -51,12 +51,13 @@ static int __init test_find_first_bit(void *bitmap, unsigned long len)
static int __init test_find_next_bit(const void *bitmap, unsigned long len)
{
- unsigned long i, cnt;
+ unsigned long i = 0, cnt = 0;
ktime_t time;
time = ktime_get();
- for (cnt = i = 0; i < BITMAP_LEN; cnt++)
- i = find_next_bit(bitmap, BITMAP_LEN, i) + 1;
+ do {
+ i = find_next_bit(bitmap, BITMAP_LEN, i);
+ } while (i++ < BITMAP_LEN && ++cnt);
time = ktime_get() - time;
pr_err("find_next_bit: %18llu ns, %6ld iterations\n", time, cnt);
@@ -65,12 +66,13 @@ static int __init test_find_next_bit(const void *bitmap, unsigned long len)
static int __init test_find_next_zero_bit(const void *bitmap, unsigned long len)
{
- unsigned long i, cnt;
+ unsigned long i = 0, cnt = 0;
ktime_t time;
time = ktime_get();
- for (cnt = i = 0; i < BITMAP_LEN; cnt++)
- i = find_next_zero_bit(bitmap, len, i) + 1;
+ do {
+ i = find_next_zero_bit(bitmap, len, i);
+ } while (i++ < BITMAP_LEN && ++cnt);
time = ktime_get() - time;
pr_err("find_next_zero_bit: %18llu ns, %6ld iterations\n", time, cnt);
@@ -84,27 +86,46 @@ static int __init test_find_last_bit(const void *bitmap, unsigned long len)
time = ktime_get();
do {
- cnt++;
l = find_last_bit(bitmap, len);
if (l >= len)
break;
len = l;
- } while (len);
+ } while (len >= 0 && ++cnt); /**< to find real 0 bit set. */
time = ktime_get() - time;
pr_err("find_last_bit: %18llu ns, %6ld iterations\n", time, cnt);
return 0;
}
+static int __init test_find_last_zero_bit(const void *bitmap, unsigned long len)
+{
+ unsigned long l, cnt = 0;
+ ktime_t time;
+
+ time = ktime_get();
+ do {
+ l = find_last_zero_bit(bitmap, len);
+ if (l >= len)
+ break;
+ len = l;
+ } while (len >= 0 && ++cnt); /**< to find real 0 bit set. */
+ time = ktime_get() - time;
+ pr_err("find_last_zero_bit: %18llu ns, %6ld iterations\n", time, cnt);
+
+ return 0;
+}
+
+
static int __init test_find_next_and_bit(const void *bitmap,
const void *bitmap2, unsigned long len)
{
- unsigned long i, cnt;
+ unsigned long i, cnt = 0;
ktime_t time;
time = ktime_get();
- for (cnt = i = 0; i < BITMAP_LEN; cnt++)
- i = find_next_and_bit(bitmap, bitmap2, BITMAP_LEN, i + 1);
+ do {
+ i = find_next_and_bit(bitmap, bitmap2, BITMAP_LEN, i);
+ } while (i++ < BITMAP_LEN && ++cnt);
time = ktime_get() - time;
pr_err("find_next_and_bit: %18llu ns, %6ld iterations\n", time, cnt);
@@ -123,6 +144,7 @@ static int __init find_bit_test(void)
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
+ test_find_last_zero_bit(bitmap, BITMAP_LEN);
/*
* test_find_first_bit() may take some time, so
@@ -144,6 +166,7 @@ static int __init find_bit_test(void)
test_find_next_bit(bitmap, BITMAP_LEN);
test_find_next_zero_bit(bitmap, BITMAP_LEN);
test_find_last_bit(bitmap, BITMAP_LEN);
+ test_find_last_zero_bit(bitmap, BITMAP_LEN);
test_find_first_bit(bitmap, BITMAP_LEN);
test_find_next_and_bit(bitmap, bitmap2, BITMAP_LEN);
--
2.27.0
reply other threads:[~2020-12-06 6:49 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201206064905.GA6183@ubuntu \
--to=ppbuk5246@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=arnd@arndb.de \
--cc=brendanhiggins@google.com \
--cc=broonie@kernel.org \
--cc=changbin.du@intel.com \
--cc=christian.brauner@ubuntu.com \
--cc=clm@fb.com \
--cc=dsterba@suse.com \
--cc=dushistov@mail.ru \
--cc=glider@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=josef@toxicpanda.com \
--cc=jpa@git.mail.kapsi.fi \
--cc=jpoimboe@redhat.com \
--cc=keescook@chromium.org \
--cc=krzk@kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=masahiroy@kernel.org \
--cc=matti.vaittinen@fi.rohmeurope.com \
--cc=mhiramat@kernel.org \
--cc=nivedita@alum.mit.edu \
--cc=orson.zhai@unisoc.com \
--cc=peter.enderborg@sony.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=richard.weiyang@linux.alibaba.com \
--cc=takahiro.akashi@linaro.org \
--cc=yury.norov@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox