xen-devel.lists.xenproject.org archive mirror
 help / color / mirror / Atom feed
From: Tim Deegan <tim@xen.org>
To: xen-devel@lists.xen.org
Cc: stefano.stabellini@citrix.com, keir@xen.org,
	ian.campbell@citrix.com, jbeulich@suse.com,
	andres@lagarcavilla.org
Subject: [PATCH v2] Don't take the domain lock for p2m operations.
Date: Mon, 29 Jul 2013 15:06:58 +0100	[thread overview]
Message-ID: <1375106818-1414-1-git-send-email-tim@xen.org> (raw)

P2M ops are covered by their own locks, and these uses of the domain
lock are relics of shadow-v1 code.

Signed-off-by: Tim Deegan <tim@xen.org>
---
v2: also drop a domain_lock() from ARM mm code.
---
 xen/arch/arm/mm.c   |    4 ----
 xen/arch/x86/mm.c   |    9 +++------
 xen/common/memory.c |    4 ----
 3 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index d1290cd..f301e65 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -875,13 +875,9 @@ static int xenmem_add_to_physmap_one(
         return -ENOSYS;
     }
 
-    domain_lock(d);
-
     /* Map at new location. */
     rc = guest_physmap_add_page(d, gpfn, mfn, 0);
 
-    domain_unlock(d);
-
     return rc;
 }
 
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index c00841c..e7f0e13 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4596,11 +4596,6 @@ static int xenmem_add_to_physmap_once(
         return -EINVAL;
     }
 
-    domain_lock(d);
-
-    if ( page )
-        put_page(page);
-
     /* Remove previously mapped page if it was present. */
     prev_mfn = mfn_x(get_gfn(d, xatp->gpfn, &p2mt));
     if ( mfn_valid(prev_mfn) )
@@ -4631,7 +4626,9 @@ static int xenmem_add_to_physmap_once(
     if ( xatp->space == XENMAPSPACE_gmfn ||
          xatp->space == XENMAPSPACE_gmfn_range )
         put_gfn(d, gfn);
-    domain_unlock(d);
+
+    if ( page )
+        put_page(page);
 
     return rc;
 }
diff --git a/xen/common/memory.c b/xen/common/memory.c
index 06a0d0a..50b740f 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -693,8 +693,6 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
             return rc;
         }
 
-        domain_lock(d);
-
         page = get_page_from_gfn(d, xrfp.gpfn, NULL, P2M_ALLOC);
         if ( page )
         {
@@ -704,8 +702,6 @@ long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         else
             rc = -ENOENT;
 
-        domain_unlock(d);
-
         rcu_unlock_domain(d);
 
         break;
-- 
1.7.10.4

             reply	other threads:[~2013-07-29 14:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-29 14:06 Tim Deegan [this message]
2013-07-29 14:08 ` [PATCH v2] Don't take the domain lock for p2m operations Andres Lagar-Cavilla
2013-07-29 14:08 ` Ian Campbell
2013-07-29 15:10 ` Keir Fraser

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=1375106818-1414-1-git-send-email-tim@xen.org \
    --to=tim@xen.org \
    --cc=andres@lagarcavilla.org \
    --cc=ian.campbell@citrix.com \
    --cc=jbeulich@suse.com \
    --cc=keir@xen.org \
    --cc=stefano.stabellini@citrix.com \
    --cc=xen-devel@lists.xen.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
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).