On Wed, Mar 06, 2013 at 07:46:29AM +0800, Simon Jeons wrote: > On 03/06/2013 07:38 AM, Andrew Shewmaker wrote: > >Limit the growth of the memory reserved for other processes > >to the smaller of 3% or 8MB. > > > >This affects only OVERCOMMIT_NEVER. > > > >Signed-off-by: Andrew Shewmaker <agshew@xxxxxxxxx> > > Please add changelog, otherwise it's for other guys to review. > Sorry, I'll be sure to include one in the future. And it looks like I do need a v5 ... I think this needs to be tunable like the admin reserve. The default certainly needs to be higher since this reserve is only for OVERCOMMIT_NEVER mode and 8MB is too little to allow the user to recover. I was thinking of OVERCOMMIT_GUESS mode when I chose it. v4: * Rebased onto v3.8-mmotm-2013-03-01-15-50 * No longer assumes 4kb pages * Code duplicated for nommu v3: * New patch summary because it wasn't unique New is "mm: limit growth of 3% hardcoded other user reserve" Old was "mm: tuning hardcoded reserve memory" * Limits growth to min(3% process size, some constant k) as Alan Cox suggested. I chose k=2000 pages (8MB) to allow recovery with sshd or login, bash, and top or kill v2: * Rebased onto v3.8-mmotm-2013-02-19-17-20 v1: * Based on 3.8 * Remove hardcoded 3% other user reserve in OVERCOMMIT_NEVER mode > > > >--- > > > >Rebased onto v3.8-mmotm-2013-03-01-15-50 > > > >No longer assumes 4kb pages. > >Code duplicated for nommu. > > > >diff --git a/mm/mmap.c b/mm/mmap.c > >index 49dc7d5..4eb2b1a 100644 > >--- a/mm/mmap.c > >+++ b/mm/mmap.c > >@@ -184,9 +184,11 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) > > allowed += total_swap_pages; > > /* Don't let a single process grow too big: > >- leave 3% of the size of this process for other processes */ > >+ * leave the smaller of 3% of the size of this process > >+ * or 8MB for other processes > >+ */ > > if (mm) > >- allowed -= mm->total_vm / 32; > >+ allowed -= min(mm->total_vm / 32, 1 << (23 - PAGE_SHIFT)); > > if (percpu_counter_read_positive(&vm_committed_as) < allowed) > > return 0; > >diff --git a/mm/nommu.c b/mm/nommu.c > >index f5d57a3..a93d214 100644 > >--- a/mm/nommu.c > >+++ b/mm/nommu.c > >@@ -1945,9 +1945,11 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) > > allowed += total_swap_pages; > > /* Don't let a single process grow too big: > >- leave 3% of the size of this process for other processes */ > >+ * leave the smaller of 3% of the size of this process > >+ * or 8MB for other processes > >+ */ > > if (mm) > >- allowed -= mm->total_vm / 32; > >+ allowed -= min(mm->total_vm / 32, 1 << (23 - PAGE_SHIFT)); > > if (percpu_counter_read_positive(&vm_committed_as) < allowed) > > return 0; > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>