From mboxrd@z Thu Jan 1 00:00:00 1970 From: shentino@gmail.com (Raymond Jennings) Date: Sat, 19 Dec 2015 13:41:09 -0800 Subject: [PATCH] allow strictatime to be set as a global default In-Reply-To: References: <1450449755.29773.0@smtp.gmail.com> <1450476738.11756.0@smtp.gmail.com> Message-ID: To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org How does this version look? (the other delta for the other file was untouched) Any chance it is ready to post to the big list (presumably fs with a cc to lkml)? diff --git a/fs/Kconfig b/fs/Kconfig index 6ce72d8..122a993 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -4,6 +4,20 @@ menu "File systems" +config DEFAULT_STRICTATIME + bool "Use strictatime by default" + default n + help + Use strictatime as a default mount option. + + Relatime became the default in 2007 to reduce I/O load on block devices. + + Enabling this option will restore historic behavior and provide perfectly + accurate atimes, but the increase in write load may reduce performance + and shorten the life of the block device. + + If unsure, say N. + # Use unaligned word dcache accesses config DCACHE_WORD_ACCESS bool On Fri, Dec 18, 2015 at 2:21 PM, Mandeep Sandhu wrote: > Ah yes...now it makes sense! :) > > The current 'word of caution' (about increased I/O load on block > devices), seems mild IMHO. Maybe we should we have a stricter > warning...something like enabling this option might be harmful to the > life of your block device (due to excessive writes) and will also lead > to reduced performance? > > HTH, > -mandeep > > > On Fri, Dec 18, 2015 at 2:12 PM, Raymond Jennings > wrote: > > On Fri, Dec 18, 2015 at 10:50 AM, Mandeep Sandhu > > wrote: > >> > >> You've removed the strictatime option altogether. So how does that > >> satisfy people who _do_ want it? > > > > > > ...actually it looks like I was an idiot and got my diff backwards when I > > pulled it out of git :P > > > > Here's the correct version. > > > > diff --git a/fs/Kconfig b/fs/Kconfig > > index 6ce72d8..4b917eb 100644 > > --- a/fs/Kconfig > > +++ b/fs/Kconfig > > @@ -4,6 +4,17 @@ > > > > menu "File systems" > > > > +config DEFAULT_STRICTATIME > > + bool "Use strictatime by default" > > + default n > > + help > > + Use strictatime as a default mount option. > > + > > + Strictatime preserves ancient historic behavior of keeping the > > atime field always up to date. > > + However, it was changed in 2007 to relatime to reduce I/O load > on > > block devices. > > + > > + If unsure, say N. > > + > > # Use unaligned word dcache accesses > > config DCACHE_WORD_ACCESS > > bool > > diff --git a/fs/namespace.c b/fs/namespace.c > > index 0570729..48e7c15 100644 > > --- a/fs/namespace.c > > +++ b/fs/namespace.c > > @@ -2680,9 +2680,15 @@ long do_mount(const char *dev_name, const char > __user > > *dir_name, > > if (retval) > > goto dput_out; > > > > - /* Default to relatime unless overriden */ > > +#ifdef CONFIG_DEFAULT_STRICTATIME > > + /* Default to strictatime unless overridden */ > > + if (flags & MS_RELATIME) > > + mnt_flags |= MNT_RELATIME; > > +#else > > + /* Default to relatime unless overridden */ > > if (!(flags & MS_NOATIME)) > > mnt_flags |= MNT_RELATIME; > > +#endif > > > > > > /* Separate the per-mountpoint flags */ > > if (flags & MS_NOSUID) > > > > > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20151219/06289244/attachment.html