Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762495Ab3DDPxr (ORCPT ); Thu, 4 Apr 2013 11:53:47 -0400 Received: from relay2.sgi.com ([192.48.179.30]:54649 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1762404Ab3DDPxq (ORCPT ); Thu, 4 Apr 2013 11:53:46 -0400 From: Nathan Zimmer To: viro@zeniv.linux.org.uk, akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Nathan Zimmer , "Eric W. Biederman" , David Woodhouse , Subject: [PATCH resend] fs/proc: Move kfree outside pde_unload_lock Date: Thu, 4 Apr 2013 10:53:39 -0500 Message-Id: <1365090819-25448-1-git-send-email-nzimmer@sgi.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <515D9F8A.2060505@sgi.com> References: <515D9F8A.2060505@sgi.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 57 This moves a kfree outside a spinlock to help scaling on larger (512 core) systems. This should be some relief until we can move the section to use the rcu. I ran a simple test which just reads from /proc/cpuinfo. Lower is better, as you can see the worst case scenario is improved. baseline moved kfree tasks read-sec read-sec 1 0.0141 0.0141 2 0.0140 0.0140 4 0.0140 0.0141 8 0.0145 0.0145 16 0.0553 0.0548 32 0.1688 0.1622 64 0.5017 0.3856 128 1.7005 0.9710 256 5.2513 2.6519 512 8.0529 6.2976 Cc: "Eric W. Biederman" Cc: Andrew Morton Cc: Alexander Viro Cc: David Woodhouse Cc: Acked-by: Alexey Dobriyan Signed-off-by: Nathan Zimmer --- fs/proc/inode.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 439ae688..863608b 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -403,11 +403,10 @@ static int proc_reg_release(struct inode *inode, struct file *file) } pde->pde_users++; release = pde->proc_fops->release; - if (pdeo) { + if (pdeo) list_del(&pdeo->lh); - kfree(pdeo); - } spin_unlock(&pde->pde_unload_lock); + kfree(pdeo); if (release) rv = release(inode, file); -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/