From: Joel Fernandes <joelaf@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <willy@infradead.org>,
Zhaoyang Huang <huangzhaoyang@gmail.com>,
Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
kernel-patch-test@lists.linaro.org,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.com>,
"open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH v1] kernel/trace:check the val against the available mem
Date: Fri, 30 Mar 2018 22:44:51 -0700 [thread overview]
Message-ID: <CAJWu+oovOOVX9UEw41L61NQ4Wyj+t513+E_tDfAqKik2+EP-Tg@mail.gmail.com> (raw)
In-Reply-To: <20180330230733.2bf010f2@gandalf.local.home>
On Fri, Mar 30, 2018 at 8:07 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> On Fri, 30 Mar 2018 19:18:57 -0700
> Matthew Wilcox <willy@infradead.org> wrote:
>
>> Again though, this is the same pattern as vmalloc. There are any number
>> of places where userspace can cause an arbitrarily large vmalloc to be
>> attempted (grep for kvmalloc_array for a list of promising candidates).
>> I'm pretty sure that just changing your GFP flags to GFP_KERNEL |
>> __GFP_NOWARN will give you the exact behaviour that you want with no
>> need to grub around in the VM to find out if your huge allocation is
>> likely to succeed.
>
> Not sure how this helps. Note, I don't care about consecutive pages, so
> this is not an array. It's a link list of thousands of pages. How do
> you suggest allocating them? The ring buffer is a link list of pages.
Yeah I didn't understand the suggestion either. If I remember
correctly, not using either NO_RETRY or RETRY_MAY_FAIL, and just plain
GFP_KERNEL was precisely causing the buffer_size_kb write to cause an
OOM in my testing. So I think Steven's patch does the right thing in
checking in advance.
thanks,
- Joel
next prev parent reply other threads:[~2018-03-31 5:44 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-29 10:41 [PATCH v1] kernel/trace:check the val against the available mem Zhaoyang Huang
2018-03-29 16:05 ` Steven Rostedt
2018-03-30 3:32 ` Zhaoyang Huang
2018-03-30 14:07 ` Steven Rostedt
2018-03-30 6:53 ` [Kernel-patch-test] " kbuild test robot
2018-03-30 6:54 ` kbuild test robot
2018-03-30 14:20 ` Steven Rostedt
2018-03-30 16:37 ` Joel Fernandes
2018-03-30 19:10 ` Steven Rostedt
2018-03-30 20:37 ` Joel Fernandes
2018-03-30 20:53 ` Matthew Wilcox
2018-03-30 21:30 ` Steven Rostedt
2018-03-30 21:42 ` Steven Rostedt
2018-03-30 23:38 ` Joel Fernandes
2018-03-31 1:41 ` Steven Rostedt
2018-03-31 2:18 ` Matthew Wilcox
2018-03-31 3:07 ` Steven Rostedt
2018-03-31 5:44 ` Joel Fernandes [this message]
2018-04-02 0:52 ` Zhaoyang Huang
2018-04-03 11:06 ` Michal Hocko
2018-04-03 11:51 ` Steven Rostedt
2018-04-03 12:16 ` Michal Hocko
2018-04-03 12:23 ` Steven Rostedt
2018-04-03 12:35 ` Michal Hocko
2018-04-03 13:32 ` Steven Rostedt
2018-04-03 13:56 ` Michal Hocko
2018-04-03 14:17 ` Steven Rostedt
2018-04-03 16:11 ` Michal Hocko
2018-04-03 16:59 ` Steven Rostedt
2018-04-03 22:56 ` Steven Rostedt
2018-04-04 6:20 ` Michal Hocko
2018-04-04 12:21 ` Joel Fernandes
2018-04-04 12:59 ` Steven Rostedt
2018-04-04 14:10 ` Michal Hocko
2018-04-04 14:25 ` Steven Rostedt
2018-04-04 14:42 ` Michal Hocko
2018-04-04 15:04 ` Steven Rostedt
2018-04-04 15:27 ` Michal Hocko
2018-04-04 15:38 ` Steven Rostedt
2018-04-04 2:58 ` Zhaoyang Huang
2018-04-04 6:23 ` Michal Hocko
2018-04-04 9:29 ` Zhaoyang Huang
2018-04-04 14:11 ` Steven Rostedt
2018-04-04 14:23 ` Michal Hocko
2018-04-04 14:31 ` Steven Rostedt
2018-04-04 14:47 ` Michal Hocko
2018-04-04 15:47 ` Steven Rostedt
2018-04-05 2:58 ` Matthew Wilcox
2018-04-05 4:12 ` Joel Fernandes
2018-04-05 14:22 ` Matthew Wilcox
2018-04-05 14:27 ` Michal Hocko
2018-04-05 14:34 ` Steven Rostedt
2018-04-05 15:13 ` Matthew Wilcox
2018-04-05 15:32 ` Michal Hocko
2018-04-05 16:15 ` Matthew Wilcox
2018-04-05 18:54 ` Michal Hocko
2018-04-05 20:15 ` __GFP_LOW Matthew Wilcox
2018-04-06 6:09 ` __GFP_LOW Michal Hocko
2018-04-08 4:27 ` __GFP_LOW Matthew Wilcox
2018-04-09 7:34 ` __GFP_LOW Michal Hocko
2018-04-09 15:51 ` __GFP_LOW Matthew Wilcox
2018-04-09 18:14 ` __GFP_LOW Michal Hocko
[not found] ` <CA+JonM0HG9kWb6-0iyDQ8UMxTeR-f=+ZL89t5DvvDULDC8Sfyw@mail.gmail.com>
2018-04-10 12:19 ` __GFP_LOW Matthew Wilcox
2018-04-05 14:30 ` [PATCH v1] kernel/trace:check the val against the available mem Steven Rostedt
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