From: Eric Sandeen Subject: Re: [PATCH 2/2] mke2fs: Enable lazy_itable_init on newer kernel by default Date: Mon, 24 Feb 2014 11:43:21 -0600 Message-ID: <530B84B9.1040203@redhat.com> References: <1393263666-21246-1-git-send-email-lczerner@redhat.com> <1393263666-21246-2-git-send-email-lczerner@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: tytso@mit.edu To: Lukas Czerner , linux-ext4@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:61095 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752737AbaBXRnY (ORCPT ); Mon, 24 Feb 2014 12:43:24 -0500 In-Reply-To: <1393263666-21246-2-git-send-email-lczerner@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2/24/14, 11:41 AM, Lukas Czerner wrote: > Currently is used did not specified lazy_itable_init option we rely on s/is used did not specified/if user did not specify/ :) > information from ext4 module exported via sysfs interface. However if > the ext4 module is not loaded it will not be enabled even though kernel > might support it. > > With this commit we set the default according to the kernel version, > however we still allow it to be set manually via extended option or be > enabled in case that ext4 module advertise that it supports this > feature. > > Signed-off-by: Lukas Czerner Thanks, Reviewed-by: Eric Sandeen > --- > misc/mke2fs.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/misc/mke2fs.c b/misc/mke2fs.c > index 957b4b6..e1c6d09 100644 > --- a/misc/mke2fs.c > +++ b/misc/mke2fs.c > @@ -2146,7 +2146,15 @@ profile_error: > blocksize, sys_page_size); > } > > - lazy_itable_init = 0; > + /* > + * On newer kernels we do have lazy_itable_init support. So pick the > + * right default in case ext4 module is not loaded. > + */ > + if (is_before_linux_ver(2, 6, 37)) > + lazy_itable_init = 0; > + else > + lazy_itable_init = 1; > + > if (access("/sys/fs/ext4/features/lazy_itable_init", R_OK) == 0) > lazy_itable_init = 1; > >