Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757530AbdIIPVF (ORCPT ); Sat, 9 Sep 2017 11:21:05 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34758 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753519AbdIIPVD (ORCPT ); Sat, 9 Sep 2017 11:21:03 -0400 X-Google-Smtp-Source: ADKCNb5JUySMhFdCFsxNKATFj0tOoEkhs/5SbhjLk0eWT82i7tYmw1R78cshx1zQagWNnkp+45Fs3Q== From: Gargi Sharma To: linux-kernel@vger.kernel.org Cc: riel@surriel.com, julia.lawall@lip6.fr, akpm@linux-foundation.org, mingo@kernel.org, pasha.tatashin@oracle.com, ktkhai@virtuozzo.com, oleg@redhat.com, wangkefeng.wang@park.jinmi.com, Gargi Sharma Subject: [RFC 0/2] Replace PID implementation with IDR API Date: Sat, 9 Sep 2017 18:03:15 +0530 Message-Id: X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1546 Lines: 41 This patch series replaces kernel bitmap implementation of PID allocation with IDR API. The following are the stats for pid and pid_namespace object files before and after the replacement. There is a noteworthy change between the IDR and bitmap implementation. Before text data bss dec hex filename 8447 3894 64 12405 3075 kernel/pid.o After text data bss dec hex filename 3602 324 8 3934 f5e kernel/pid.o Before text data bss dec hex filename 5692 1842 192 7726 1e2e kernel/pid_namespace.o After text data bss dec hex filename 2858 216 16 3090 c12 kernel/pid_namespace.o There wasn't a considerable difference between the time required for allocation of PIDs to the processes. The IDR implementation is a little faster than bitmap implementation. The next change in the pipeline is replacing pidhash with IDR API implementation. Gargi Sharma (2): proc: Return if nothing to unmount pid: Replace PID bitmap implementation with IDR API fs/proc/base.c | 4 + include/linux/pid.h | 1 + include/linux/pid_namespace.h | 5 +- init/main.c | 4 +- kernel/pid.c | 204 ++++++++---------------------------------- kernel/pid_namespace.c | 39 ++++---- 6 files changed, 63 insertions(+), 194 deletions(-) -- 2.7.4