From: Michal Hocko <mhocko@kernel.org>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: viro@zeniv.linux.org.uk, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] seq_file: account everything
Date: Fri, 16 Mar 2018 13:43:42 +0100 [thread overview]
Message-ID: <20180316124342.GB11461@dhcp22.suse.cz> (raw)
In-Reply-To: <20180310085252.GB17121@avx2>
On Sat 10-03-18 11:52:52, Alexey Dobriyan wrote:
> All it takes to open a file and read 1 byte from it.
>
> seq_file will be allocated along with any private allocations,
> and more importantly seq file buffer which is 1 page by default.
OOM badness heuristic will not know about this memory when choosing an
oom victim so we might kill a wrong victim which is not all that great
but at least the consumption will be contained within a memcg which
sounds like the sufficient protection for now. This is the case
basically for all kmem charges...
The seq file life time should be bound to a process life time so this is
OK.
> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
>
> fs/seq_file.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> --- a/fs/seq_file.c
> +++ b/fs/seq_file.c
> @@ -29,7 +29,7 @@ static void seq_set_overflow(struct seq_file *m)
>
> static void *seq_buf_alloc(unsigned long size)
> {
> - return kvmalloc(size, GFP_KERNEL);
> + return kvmalloc(size, GFP_KERNEL_ACCOUNT);
> }
>
> /**
> @@ -566,7 +566,7 @@ static void single_stop(struct seq_file *p, void *v)
> int single_open(struct file *file, int (*show)(struct seq_file *, void *),
> void *data)
> {
> - struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL);
> + struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL_ACCOUNT);
> int res = -ENOMEM;
>
> if (op) {
> @@ -628,7 +628,7 @@ void *__seq_open_private(struct file *f, const struct seq_operations *ops,
> void *private;
> struct seq_file *seq;
>
> - private = kzalloc(psize, GFP_KERNEL);
> + private = kzalloc(psize, GFP_KERNEL_ACCOUNT);
> if (private == NULL)
> goto out;
>
> @@ -1112,5 +1112,5 @@ EXPORT_SYMBOL(seq_hlist_next_percpu);
>
> void __init seq_file_init(void)
> {
> - seq_file_cache = KMEM_CACHE(seq_file, SLAB_PANIC);
> + seq_file_cache = KMEM_CACHE(seq_file, SLAB_ACCOUNT|SLAB_PANIC);
> }
--
Michal Hocko
SUSE Labs
prev parent reply other threads:[~2018-03-16 12:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-10 8:52 [PATCH 2/2] seq_file: account everything Alexey Dobriyan
2018-03-16 12:43 ` Michal Hocko [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180316124342.GB11461@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).