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[46.53.177.92]) by smtp.gmail.com with ESMTPSA id u3-v6sm173918edo.44.2018.08.27.16.15.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Aug 2018 16:15:39 -0700 (PDT) From: Alexey Dobriyan To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, Alexey Dobriyan Subject: [PATCH 09/13] proc: convert dentry flushing on exit to _print_integer() Date: Tue, 28 Aug 2018 02:14:59 +0300 Message-Id: <20180827231503.26899-9-adobriyan@gmail.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180827231503.26899-1-adobriyan@gmail.com> References: <20180827231503.26899-1-adobriyan@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Benchmark fork+exit+waitpid 2^16 times: 6.579161299 seconds time elapsed ( +- 0.24% ) 6.482729157 seconds time elapsed ( +- 0.42% ) -1.5% Dentry flushing is very small part of exit(2), effects should be more visible on a tiny 1-page process which doesn't uses libc. Signed-off-by: Alexey Dobriyan --- fs/proc/base.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 17666bd61ac8..79d2f7d72ad1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3022,11 +3022,11 @@ static const struct inode_operations proc_tgid_base_inode_operations = { static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) { struct dentry *dentry, *leader, *dir; - char buf[10 + 1]; + char buf[10]; struct qstr name; - name.name = buf; - name.len = snprintf(buf, sizeof(buf), "%u", pid); + name.name = _print_integer_u32(buf + sizeof(buf), pid); + name.len = buf + sizeof(buf) - (char *)name.name; /* no ->d_hash() rejects on procfs */ dentry = d_hash_and_lookup(mnt->mnt_root, &name); if (dentry) { @@ -3037,8 +3037,8 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) if (pid == tgid) return; - name.name = buf; - name.len = snprintf(buf, sizeof(buf), "%u", tgid); + name.name = _print_integer_u32(buf + sizeof(buf), tgid); + name.len = buf + sizeof(buf) - (char *)name.name; leader = d_hash_and_lookup(mnt->mnt_root, &name); if (!leader) goto out; @@ -3049,8 +3049,8 @@ static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid) if (!dir) goto out_put_leader; - name.name = buf; - name.len = snprintf(buf, sizeof(buf), "%u", pid); + name.name = _print_integer_u32(buf + sizeof(buf), pid); + name.len = buf + sizeof(buf) - (char *)name.name; dentry = d_hash_and_lookup(dir, &name); if (dentry) { d_invalidate(dentry); -- 2.16.4