lkml.org 
[lkml]   [2009]   [Jul]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH 2/3] profile: Suppress warning about large allocations when profile=1 is specified
Date
> On Thu, Jul 16, 2009 at 10:12:20AM +0900, KOSAKI Motohiro wrote:
> > > When profile= is used, a large buffer is allocated early at boot. This
> > > can be larger than what the page allocator can provide so it prints a
> > > warning. However, the caller is able to handle the situation so this patch
> > > suppresses the warning.
> >
> > I'm confused.
> >
> > Currently caller doesn't handle error return.
> >
> > ----------------------------------------------------------
> > asmlinkage void __init start_kernel(void)
> > {
> > (snip)
> > init_timers();
> > hrtimers_init();
> > softirq_init();
> > timekeeping_init();
> > time_init();
> > sched_clock_init();
> > profile_init(); <-- ignore return value
> > ------------------------------------------------------------
> >
> > and, if user want to use linus profiler, the user should choice select
> > proper bucket size by boot parameter.
> > Currently, allocation failure message tell user about specified bucket size
> > is wrong.
> > I think this patch hide it.
> >
>
> Look at what profile_init() itself is doing. You can't see it from the
> patch context but when alloc_pages_exact() fails, it calls vmalloc(). If
> that fails, profiling is just disabled. There isn't really anything the
> caller of profile_init() can do about it and the page allocator doesn't
> need to scream about it.

Indeed. Thanks correct me.
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

>
> >
> > >
> > > Signed-off-by: Mel Gorman <mel@csn.ul.ie>
> > > ---
> > > kernel/profile.c | 5 +++--
> > > 1 files changed, 3 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/kernel/profile.c b/kernel/profile.c
> > > index 69911b5..419250e 100644
> > > --- a/kernel/profile.c
> > > +++ b/kernel/profile.c
> > > @@ -117,11 +117,12 @@ int __ref profile_init(void)
> > >
> > > cpumask_copy(prof_cpu_mask, cpu_possible_mask);
> > >
> > > - prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL);
> > > + prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN);
> > > if (prof_buffer)
> > > return 0;
> > >
> > > - prof_buffer = alloc_pages_exact(buffer_bytes, GFP_KERNEL|__GFP_ZERO);
> > > + prof_buffer = alloc_pages_exact(buffer_bytes,
> > > + GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
> > > if (prof_buffer)
> > > return 0;
> >
> >
> >
>
> --
> Mel Gorman
> Part-time Phd Student Linux Technology Center
> University of Limerick IBM Dublin Software Lab





\
 
 \ /
  Last update: 2009-07-17 01:47    [W:0.031 / U:0.548 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site