Messages in this thread | | | Date | Tue, 19 May 2015 10:17:55 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 10/19] x86, mpx: Trace the attempts to find bounds tables |
| |
On Mon, 18 May 2015, Dave Hansen wrote: > > From: Dave Hansen <dave.hansen@linux.intel.com> > > There are two different events being traced here. They are > doing similar things so share a trace "EVENT_CLASS" and are > presented together. > > 1. Trace when MPX is zapping pages "mpx_unmap_zap": > > When MPX can not free an entire bounds table, it will > instead try to zap unused parts of a bounds table to free > the backing memory. This decreases RSS (resident set > size) without decreasing the virtual space allocated > for bounds tables. > > 2. Trace attempts to find bounds tables "mpx_unmap_search": > > This event traces any time we go looking to unmap a > bounds table for a given virtual address range. This is > useful to ensure that the kernel actually "tried" to free > a bounds table versus times it succeeded in finding one. > > It might try and fail if it realized that a table was > shared with an adjacent VMA which is not being unmapped. > > Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
| |