LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Juergen Gross <jgross@suse.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	Matthew Auld <matthew.auld@intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Minchan Kim <minchan@kernel.org>,
	Matthew Wilcox <willy@infradead.org>,
	Nitin Gupta <ngupta@vflare.org>,
	x86@kernel.org, xen-devel@lists.xenproject.org,
	linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org,
	dri-devel@lists.freedesktop.org, linux-mm@kvack.org
Subject: [PATCH 01/10] mm: update the documentation for vfree
Date: Wed, 30 Sep 2020 19:51:24 +0200
Message-ID: <20200930175133.1252382-2-hch@lst.de> (raw)
In-Reply-To: <20200930175133.1252382-1-hch@lst.de>

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

 * Document that you can call vfree() on an address returned from vmap()
 * Remove the note about the minimum size -- the minimum size of a vmalloc
   allocation is one page
 * Add a Context: section
 * Fix capitalisation
 * Reword the prohibition on calling from NMI context to avoid a double
   negative

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/vmalloc.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index be4724b916b3e7..8770260419af06 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2321,20 +2321,21 @@ static void __vfree(const void *addr)
 }
 
 /**
- * vfree - release memory allocated by vmalloc()
- * @addr:  memory base address
+ * vfree - Release memory allocated by vmalloc()
+ * @addr:  Memory base address
  *
- * Free the virtually continuous memory area starting at @addr, as
- * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
- * NULL, no operation is performed.
+ * Free the virtually continuous memory area starting at @addr, as obtained
+ * from one of the vmalloc() family of APIs.  This will usually also free the
+ * physical memory underlying the virtual allocation, but that memory is
+ * reference counted, so it will not be freed until the last user goes away.
  *
- * Must not be called in NMI context (strictly speaking, only if we don't
- * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
- * conventions for vfree() arch-depenedent would be a really bad idea)
+ * If @addr is NULL, no operation is performed.
  *
+ * Context:
  * May sleep if called *not* from interrupt context.
- *
- * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
+ * Must not be called in NMI context (strictly speaking, it could be
+ * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-depenedent would be a really bad idea).
  */
 void vfree(const void *addr)
 {
-- 
2.28.0


  reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-30 17:51 remove alloc_vm_area v3 Christoph Hellwig
2020-09-30 17:51 ` Christoph Hellwig [this message]
2020-09-30 17:51 ` [PATCH 02/10] mm: add a VM_MAP_PUT_PAGES flag for vmap Christoph Hellwig
2020-09-30 17:51 ` [PATCH 03/10] mm: add a vmap_pfn function Christoph Hellwig
2020-09-30 17:51 ` [PATCH 04/10] mm: allow a NULL fn callback in apply_to_page_range Christoph Hellwig
2020-09-30 17:51 ` [PATCH 05/10] zsmalloc: switch from alloc_vm_area to get_vm_area Christoph Hellwig
2020-09-30 17:51 ` [PATCH 06/10] drm/i915: use vmap in shmem_pin_map Christoph Hellwig
2020-09-30 17:51 ` [PATCH 07/10] drm/i915: use vmap in i915_gem_object_map Christoph Hellwig
2020-09-30 17:51 ` [PATCH 08/10] xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv Christoph Hellwig
2020-09-30 17:51 ` [PATCH 09/10] x86/xen: open code alloc_vm_area in arch_gnttab_valloc Christoph Hellwig
2020-09-30 17:51 ` [PATCH 10/10] mm: remove alloc_vm_area Christoph Hellwig

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=20200930175133.1252382-2-hch@lst.de \
    --to=hch@lst.de \
    --cc=akpm@linux-foundation.org \
    --cc=boris.ostrovsky@oracle.com \
    --cc=chris@chris-wilson.co.uk \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=jani.nikula@linux.intel.com \
    --cc=jgross@suse.com \
    --cc=joonas.lahtinen@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=matthew.auld@intel.com \
    --cc=minchan@kernel.org \
    --cc=ngupta@vflare.org \
    --cc=peterz@infradead.org \
    --cc=rodrigo.vivi@intel.com \
    --cc=sstabellini@kernel.org \
    --cc=tvrtko.ursulin@linux.intel.com \
    --cc=willy@infradead.org \
    --cc=x86@kernel.org \
    --cc=xen-devel@lists.xenproject.org \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git
	git clone --mirror https://lore.kernel.org/lkml/10 lkml/git/10.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git