From: "NeilBrown" <neilb@suse.de>
To: "Michal Hocko" <mhocko@kernel.org>
Cc: linux-mm@kvack.org, "Dave Chinner" <david@fromorbit.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Christoph Hellwig" <hch@infradead.org>,
"Uladzislau Rezki" <urezki@gmail.com>,
linux-fsdevel@vger.kernel.org,
"LKML" <linux-kernel@vger.kernel.org>,
"Ilya Dryomov" <idryomov@gmail.com>,
"Jeff Layton" <jlayton@kernel.org>,
"Michal Hocko" <mhocko@suse.com>
Subject: Re: [PATCH 4/4] mm: allow !GFP_KERNEL allocations for kvmalloc
Date: Tue, 26 Oct 2021 10:34:34 +1100 [thread overview]
Message-ID: <163520487423.16092.18303917539436351482@noble.neil.brown.name> (raw)
In-Reply-To: <20211025150223.13621-5-mhocko@kernel.org>
On Tue, 26 Oct 2021, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> A support for GFP_NO{FS,IO} and __GFP_NOFAIL has been implemented
> by previous patches so we can allow the support for kvmalloc. This
> will allow some external users to simplify or completely remove
> their helpers.
>
> GFP_NOWAIT semantic hasn't been supported so far but it hasn't been
> explicitly documented so let's add a note about that.
>
> ceph_kvmalloc is the first helper to be dropped and changed to
> kvmalloc.
>
> Signed-off-by: Michal Hocko <mhocko@suse.com>
> ---
> include/linux/ceph/libceph.h | 1 -
> mm/util.c | 15 ++++-----------
> net/ceph/buffer.c | 4 ++--
> net/ceph/ceph_common.c | 27 ---------------------------
> net/ceph/crypto.c | 2 +-
> net/ceph/messenger.c | 2 +-
> net/ceph/messenger_v2.c | 2 +-
> net/ceph/osdmap.c | 12 ++++++------
> 8 files changed, 15 insertions(+), 50 deletions(-)
>
> diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h
> index 409d8c29bc4f..309acbcb5a8a 100644
> --- a/include/linux/ceph/libceph.h
> +++ b/include/linux/ceph/libceph.h
> @@ -295,7 +295,6 @@ extern bool libceph_compatible(void *data);
>
> extern const char *ceph_msg_type_name(int type);
> extern int ceph_check_fsid(struct ceph_client *client, struct ceph_fsid *fsid);
> -extern void *ceph_kvmalloc(size_t size, gfp_t flags);
>
> struct fs_parameter;
> struct fc_log;
> diff --git a/mm/util.c b/mm/util.c
> index bacabe446906..fdec6b4b1267 100644
> --- a/mm/util.c
> +++ b/mm/util.c
> @@ -549,13 +549,10 @@ EXPORT_SYMBOL(vm_mmap);
> * Uses kmalloc to get the memory but if the allocation fails then falls back
> * to the vmalloc allocator. Use kvfree for freeing the memory.
> *
> - * Reclaim modifiers - __GFP_NORETRY and __GFP_NOFAIL are not supported.
> + * Reclaim modifiers - __GFP_NORETRY and GFP_NOWAIT are not supported.
GFP_NOWAIT is not a modifier. It is a base value that can be modified.
I think you mean that
__GFP_NORETRY is not supported and __GFP_DIRECT_RECLAIM is required
But I really cannot see why either of these statements are true.
Before your patch, __GFP_NORETRY would have forced use of kmalloc, so
that would mean it isn't really supported. But that doesn't happen any more.
Thanks,
NeilBrown
next prev parent reply other threads:[~2021-10-25 23:34 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 15:02 [PATCH 0/4] extend vmalloc support for constrained allocations Michal Hocko
2021-10-25 15:02 ` [PATCH 1/4] mm/vmalloc: alloc GFP_NO{FS,IO} for vmalloc Michal Hocko
2021-10-25 15:02 ` [PATCH 2/4] mm/vmalloc: add support for __GFP_NOFAIL Michal Hocko
2021-10-25 22:59 ` NeilBrown
2021-10-26 7:03 ` Michal Hocko
2021-10-26 10:30 ` NeilBrown
2021-10-26 11:29 ` Michal Hocko
2021-10-26 15:48 ` Uladzislau Rezki
2021-10-26 16:28 ` Michal Hocko
2021-10-26 19:33 ` Uladzislau Rezki
2021-10-27 6:46 ` Michal Hocko
2021-10-27 17:55 ` Uladzislau Rezki
2021-10-29 7:57 ` Michal Hocko
2021-10-29 14:05 ` Uladzislau Rezki
2021-10-29 14:45 ` Michal Hocko
2021-10-29 17:23 ` Uladzislau Rezki
2021-10-25 15:02 ` [PATCH 3/4] mm/vmalloc: be more explicit about supported gfp flags Michal Hocko
2021-10-25 23:26 ` NeilBrown
2021-10-26 7:10 ` Michal Hocko
2021-10-26 10:43 ` NeilBrown
2021-10-26 12:20 ` Michal Hocko
2021-10-25 15:02 ` [PATCH 4/4] mm: allow !GFP_KERNEL allocations for kvmalloc Michal Hocko
2021-10-25 23:34 ` NeilBrown [this message]
2021-10-26 7:15 ` Michal Hocko
2021-10-26 10:48 ` NeilBrown
2021-10-26 12:23 ` Michal Hocko
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=163520487423.16092.18303917539436351482@noble.neil.brown.name \
--to=neilb@suse.de \
--cc=akpm@linux-foundation.org \
--cc=david@fromorbit.com \
--cc=hch@infradead.org \
--cc=idryomov@gmail.com \
--cc=jlayton@kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@kernel.org \
--cc=mhocko@suse.com \
--cc=urezki@gmail.com \
/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).