Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-08 Thread Christopher Lameter
On Thu, 8 Mar 2018, Chintan Pandya wrote: > > If you print the raw value, then you can do the subtraction yourself; > > if you've subtracted it from jiffies each time, you've at least introduced > > jitter, and possibly enough jitter to confuse and mislead. > > > This is exactly what I was

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-08 Thread Christopher Lameter
On Thu, 8 Mar 2018, Chintan Pandya wrote: > > If you print the raw value, then you can do the subtraction yourself; > > if you've subtracted it from jiffies each time, you've at least introduced > > jitter, and possibly enough jitter to confuse and mislead. > > > This is exactly what I was

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Chintan Pandya
On 3/7/2018 11:52 PM, Matthew Wilcox wrote: On Wed, Mar 07, 2018 at 12:13:56PM -0600, Christopher Lameter wrote: On Wed, 7 Mar 2018, Chintan Pandya wrote: In this case, object got freed later but 'age' shows otherwise. This could be because, while printing this info, we print allocation

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Chintan Pandya
On 3/7/2018 11:52 PM, Matthew Wilcox wrote: On Wed, Mar 07, 2018 at 12:13:56PM -0600, Christopher Lameter wrote: On Wed, 7 Mar 2018, Chintan Pandya wrote: In this case, object got freed later but 'age' shows otherwise. This could be because, while printing this info, we print allocation

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Matthew Wilcox
On Wed, Mar 07, 2018 at 12:13:56PM -0600, Christopher Lameter wrote: > On Wed, 7 Mar 2018, Chintan Pandya wrote: > > In this case, object got freed later but 'age' shows > > otherwise. This could be because, while printing > > this info, we print allocation traces first and > > free traces

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Matthew Wilcox
On Wed, Mar 07, 2018 at 12:13:56PM -0600, Christopher Lameter wrote: > On Wed, 7 Mar 2018, Chintan Pandya wrote: > > In this case, object got freed later but 'age' shows > > otherwise. This could be because, while printing > > this info, we print allocation traces first and > > free traces

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Christopher Lameter
On Wed, 7 Mar 2018, Chintan Pandya wrote: > In this case, object got freed later but 'age' shows > otherwise. This could be because, while printing > this info, we print allocation traces first and > free traces thereafter. In between, if we get schedule > out, (jiffies - t->when) could become

Re: [PATCH] slub: Fix misleading 'age' in verbose slub prints

2018-03-07 Thread Christopher Lameter
On Wed, 7 Mar 2018, Chintan Pandya wrote: > In this case, object got freed later but 'age' shows > otherwise. This could be because, while printing > this info, we print allocation traces first and > free traces thereafter. In between, if we get schedule > out, (jiffies - t->when) could become