From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Thu, 31 Mar 2011 01:33:29 +0000 (+0200)
Subject: perf: Rebase max unprivileged mlock threshold on top of page size
X-Git-Tag: Ubuntu-5.0.0-8.9~19335^2~3
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=20443384fe090c5f8aeb016e7e85659c5bbdd69f;p=mirror_ubuntu-disco-kernel.git

perf: Rebase max unprivileged mlock threshold on top of page size

Ensure we allow 512 kiB + 1 page for user control without
assuming a 4096 bytes page size.

Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: <stable@kernel.org>
LKML-Reference: <1301535209-9679-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index c75925c4d1e2..261690923ffb 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -145,8 +145,8 @@ static struct srcu_struct pmus_srcu;
  */
 int sysctl_perf_event_paranoid __read_mostly = 1;
 
-/* Minimum for 128 pages + 1 for the user control page */
-int sysctl_perf_event_mlock __read_mostly = 516; /* 'free' kb per user */
+/* Minimum for 512 kiB + 1 user control page */
+int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */
 
 /*
  * max perf event sample rate