[patch 098/123] fs/proc/base.c: save decrement during lookup/readdir in /proc/$PID

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: fs/proc/base.c: save decrement during lookup/readdir in /proc/$PID

Comparison for "<" works equally well as comparison for "<="
but one SUB/LEA is saved (no, it is not optimised away, at least here).

Link: http://lkml.kernel.org/r/20161122195143.GA29812@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 fs/proc/base.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff -puN fs/proc/base.c~proc-save-decrement-during-lookup-readdir-in-proc-pid fs/proc/base.c
--- a/fs/proc/base.c~proc-save-decrement-during-lookup-readdir-in-proc-pid
+++ a/fs/proc/base.c
@@ -2412,14 +2412,14 @@ static struct dentry *proc_pident_lookup
 	 * Yes, it does not scale. And it should not. Don't add
 	 * new entries into /proc/<tgid>/ without very good reasons.
 	 */
-	last = &ents[nents - 1];
-	for (p = ents; p <= last; p++) {
+	last = &ents[nents];
+	for (p = ents; p < last; p++) {
 		if (p->len != dentry->d_name.len)
 			continue;
 		if (!memcmp(dentry->d_name.name, p->name, p->len))
 			break;
 	}
-	if (p > last)
+	if (p >= last)
 		goto out;
 
 	error = proc_pident_instantiate(dir, dentry, task, p);
@@ -2444,7 +2444,7 @@ static int proc_pident_readdir(struct fi
 	if (ctx->pos >= nents + 2)
 		goto out;
 
-	for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
+	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
 		if (!proc_fill_cache(file, ctx, p->name, p->len,
 				proc_pident_instantiate, task, p))
 			break;
_
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux