Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH 2/3] profile: Suppress warning about large allocations when profile=1 is specified | Date | Fri, 17 Jul 2009 08:43:27 +0900 (JST) |
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> 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
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