On Thu, Apr 11, 2013 at 12:59:38AM -0400, Naoya Horiguchi wrote:
> Hi Tanino-san,
>
> On Thu, Apr 11, 2013 at 12:27:15PM +0900, Mitsuhiro Tanino wrote:
> > This patch introduces new sysctl interfaces in order to limit
> > a rate of outputting memory error messages.
> >
> > - vm.memory_failure_print_ratelimit:
> > Specify the minimum length of time between messages.
> > By default the rate limiting is disabled.
> >
> > - vm.memory_failure_print_ratelimit_burst:
> > Specify the number of messages we can send before rate limiting.
> >
> > Signed-off-by: Mitsuhiro Tanino <mitsuhiro.tanino.gm@xxxxxxxxxxx>
...
> > @@ -78,6 +79,16 @@ EXPORT_SYMBOL_GPL(hwpoison_filter_dev_minor);
> > EXPORT_SYMBOL_GPL(hwpoison_filter_flags_mask);
> > EXPORT_SYMBOL_GPL(hwpoison_filter_flags_value);
> >
> > +/*
> > + * This enforces a rate limit for outputting error message.
> > + * The default interval is set to "0" HZ. This means that
> > + * outputting error message is not limited by default.
> > + * The default burst is set to "10". This parameter can control
> > + * to output number of messages per interval.
> > + * If interval is set to "0", the burst is ineffective.
> > + */
> > +DEFINE_RATELIMIT_STATE(sysctl_memory_failure_print_ratelimit, 0 * HZ, 10);
> > +
> > static int hwpoison_filter_dev(struct page *p)
> > {
> > struct address_space *mapping;
> > @@ -622,13 +633,16 @@ static int me_pagecache_dirty(struct page *p, unsigned long pfn)
> > SetPageError(p);
> > if (mapping) {
> > /* Print more information about the file. */
> > - if (mapping->host != NULL && S_ISREG(mapping->host->i_mode))
> > - pr_info("MCE %#lx: File was corrupted: Dev:%s Inode:%lu Offset:%lu\n",
> > - page_to_pfn(p), mapping->host->i_sb->s_id,
> > - mapping->host->i_ino, page_index(p));
> > - else
> > - pr_info("MCE %#lx: A dirty page cache was corrupted.\n",
> > - page_to_pfn(p));
> > + if (__ratelimit(&sysctl_memory_failure_print_ratelimit)) {
> > + if (mapping->host != NULL &&
> > + S_ISREG(mapping->host->i_mode))
> > + pr_info("MCE %#lx: File was corrupted: Dev:%s Inode:%lu Offset:%lu\n",
> > + page_to_pfn(p), mapping->host->i_sb->s_id,
> > + mapping->host->i_ino, page_index(p));
> > + else
> > + pr_info("MCE %#lx: A dirty page cache was corrupted.\n",
> > + page_to_pfn(p));
> > + }
> >
> > /*
> > * IO error will be reported by write(), fsync(), etc.
I don't think it's enough to do ratelimit only for me_pagecache_dirty().
When tons of memory errors flood, all of printk()s in memory error handler
can print out tons of messages.
Thanks,
Naoya
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