From: Olaf Hering <olaf@aepfle.de>
To: xen-devel@lists.xensource.com
Subject: [PATCH 08/12] xenpaging: drop paged pages in guest_remove_page
Date: Mon, 10 Jan 2011 17:43:53 +0100 [thread overview]
Message-ID: <20110110164348.394538387@aepfle.de> (raw)
In-Reply-To: 20110110164345.521919826@aepfle.de
[-- Attachment #1: xen-unstable.xenpaging.guest_remove_page.patch --]
[-- Type: text/plain, Size: 7306 bytes --]
Simply drop paged-pages in guest_remove_page(), and notify xenpaging to
drop its reference to the gfn. If the ring is full, the page will
remain in paged-out state in xenpaging. This is not an issue, it just
means this gfn will not be nominated again.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
v3:
send one-way notification to pager to release page
use new mem_event_check_ring() feature to not pause vcpu when ring is full
v2:
resume dropped page to unpause vcpus
tools/xenpaging/xenpaging.c | 39 ++++++++++++++++++++------------
xen/arch/x86/mm/p2m.c | 49 ++++++++++++++++++++++++++++++-----------
xen/common/memory.c | 6 +++++
xen/include/asm-x86/p2m.h | 4 +++
xen/include/public/mem_event.h | 1
5 files changed, 72 insertions(+), 27 deletions(-)
--- xen-unstable.hg-4.1.22694.orig/tools/xenpaging/xenpaging.c
+++ xen-unstable.hg-4.1.22694/tools/xenpaging/xenpaging.c
@@ -638,25 +638,34 @@ int main(int argc, char *argv[])
goto out;
}
- /* Populate the page */
- rc = xenpaging_populate_page(paging, &req.gfn, fd, i);
- if ( rc != 0 )
+ if ( req.flags & MEM_EVENT_FLAG_DROP_PAGE )
{
- ERROR("Error populating page");
- goto out;
+ DPRINTF("drop_page ^ gfn %"PRIx64" pageslot %d\n", req.gfn, i);
+ /* Notify policy of page being dropped */
+ policy_notify_paged_in(req.gfn);
}
+ else
+ {
+ /* Populate the page */
+ rc = xenpaging_populate_page(paging, &req.gfn, fd, i);
+ if ( rc != 0 )
+ {
+ ERROR("Error populating page");
+ goto out;
+ }
- /* Prepare the response */
- rsp.gfn = req.gfn;
- rsp.p2mt = req.p2mt;
- rsp.vcpu_id = req.vcpu_id;
- rsp.flags = req.flags;
+ /* Prepare the response */
+ rsp.gfn = req.gfn;
+ rsp.p2mt = req.p2mt;
+ rsp.vcpu_id = req.vcpu_id;
+ rsp.flags = req.flags;
- rc = xenpaging_resume_page(paging, &rsp, 1);
- if ( rc != 0 )
- {
- ERROR("Error resuming page");
- goto out;
+ rc = xenpaging_resume_page(paging, &rsp, 1);
+ if ( rc != 0 )
+ {
+ ERROR("Error resuming page");
+ goto out;
+ }
}
/* Evict a new page to replace the one we just paged in */
--- xen-unstable.hg-4.1.22694.orig/xen/arch/x86/mm/p2m.c
+++ xen-unstable.hg-4.1.22694/xen/arch/x86/mm/p2m.c
@@ -2211,12 +2211,15 @@ p2m_remove_page(struct p2m_domain *p2m,
P2M_DEBUG("removing gfn=%#lx mfn=%#lx\n", gfn, mfn);
- for ( i = 0; i < (1UL << page_order); i++ )
+ if ( mfn_valid(_mfn(mfn)) )
{
- mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, p2m_query);
- if ( !p2m_is_grant(t) )
- set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
- ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
+ for ( i = 0; i < (1UL << page_order); i++ )
+ {
+ mfn_return = p2m->get_entry(p2m, gfn + i, &t, &a, p2m_query);
+ if ( !p2m_is_grant(t) )
+ set_gpfn_from_mfn(mfn+i, INVALID_M2P_ENTRY);
+ ASSERT( !p2m_is_valid(t) || mfn + i == mfn_x(mfn_return) );
+ }
}
set_p2m_entry(p2m, gfn, _mfn(INVALID_MFN), page_order, p2m_invalid, p2m->default_access);
}
@@ -2772,6 +2775,25 @@ int p2m_mem_paging_evict(struct p2m_doma
return 0;
}
+void p2m_mem_paging_drop_page(struct p2m_domain *p2m, unsigned long gfn)
+{
+ struct vcpu *v = current;
+ mem_event_request_t req;
+ struct domain *d = p2m->domain;
+
+ /* Check that there's space on the ring for this request */
+ if ( mem_event_check_ring(d) == 0)
+ {
+ /* Send release notification to pager */
+ memset(&req, 0, sizeof(req));
+ req.flags |= MEM_EVENT_FLAG_DROP_PAGE;
+ req.gfn = gfn;
+ req.vcpu_id = v->vcpu_id;
+
+ mem_event_put_request(d, &req);
+ }
+}
+
void p2m_mem_paging_populate(struct p2m_domain *p2m, unsigned long gfn)
{
struct vcpu *v = current;
@@ -2846,13 +2868,16 @@ void p2m_mem_paging_resume(struct p2m_do
/* Pull the response off the ring */
mem_event_get_response(d, &rsp);
- /* Fix p2m entry */
- mfn = gfn_to_mfn(p2m, rsp.gfn, &p2mt);
- p2m_lock(p2m);
- set_p2m_entry(p2m, rsp.gfn, mfn, 0, p2m_ram_rw, p2m->default_access);
- set_gpfn_from_mfn(mfn_x(mfn), gfn);
- audit_p2m(p2m, 1);
- p2m_unlock(p2m);
+ /* Fix p2m entry if the page was not dropped */
+ if ( !(rsp.flags & MEM_EVENT_FLAG_DROP_PAGE) )
+ {
+ mfn = gfn_to_mfn(p2m, rsp.gfn, &p2mt);
+ p2m_lock(p2m);
+ set_p2m_entry(p2m, rsp.gfn, mfn, 0, p2m_ram_rw, p2m->default_access);
+ set_gpfn_from_mfn(mfn_x(mfn), rsp.gfn);
+ audit_p2m(p2m, 1);
+ p2m_unlock(p2m);
+ }
/* Unpause domain */
if ( rsp.flags & MEM_EVENT_FLAG_VCPU_PAUSED )
--- xen-unstable.hg-4.1.22694.orig/xen/common/memory.c
+++ xen-unstable.hg-4.1.22694/xen/common/memory.c
@@ -163,6 +163,12 @@ int guest_remove_page(struct domain *d,
#ifdef CONFIG_X86
mfn = mfn_x(gfn_to_mfn(p2m_get_hostp2m(d), gmfn, &p2mt));
+ if ( unlikely(p2m_is_paging(p2mt)) )
+ {
+ guest_physmap_remove_page(d, gmfn, mfn, 0);
+ p2m_mem_paging_drop_page(p2m_get_hostp2m(d), gmfn);
+ return 1;
+ }
#else
mfn = gmfn_to_mfn(d, gmfn);
#endif
--- xen-unstable.hg-4.1.22694.orig/xen/include/asm-x86/p2m.h
+++ xen-unstable.hg-4.1.22694/xen/include/asm-x86/p2m.h
@@ -511,6 +511,8 @@ int set_shared_p2m_entry(struct p2m_doma
int p2m_mem_paging_nominate(struct p2m_domain *p2m, unsigned long gfn);
/* Evict a frame */
int p2m_mem_paging_evict(struct p2m_domain *p2m, unsigned long gfn);
+/* Tell xenpaging to drop a paged out frame */
+void p2m_mem_paging_drop_page(struct p2m_domain *p2m, unsigned long gfn);
/* Start populating a paged out frame */
void p2m_mem_paging_populate(struct p2m_domain *p2m, unsigned long gfn);
/* Prepare the p2m for paging a frame in */
@@ -518,6 +520,8 @@ int p2m_mem_paging_prep(struct p2m_domai
/* Resume normal operation (in case a domain was paused) */
void p2m_mem_paging_resume(struct p2m_domain *p2m);
#else
+static inline void p2m_mem_paging_drop_page(struct p2m_domain *p2m, unsigned long gfn)
+{ }
static inline void p2m_mem_paging_populate(struct p2m_domain *p2m, unsigned long gfn)
{ }
#endif
--- xen-unstable.hg-4.1.22694.orig/xen/include/public/mem_event.h
+++ xen-unstable.hg-4.1.22694/xen/include/public/mem_event.h
@@ -33,6 +33,7 @@
/* Memory event flags */
#define MEM_EVENT_FLAG_VCPU_PAUSED (1 << 0)
+#define MEM_EVENT_FLAG_DROP_PAGE (1 << 1)
/* Reasons for the memory event request */
#define MEM_EVENT_REASON_UNKNOWN 0 /* typical reason */
next prev parent reply other threads:[~2011-01-10 16:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-10 16:43 [PATCH 00/12] xenpaging changes for xen-unstable Olaf Hering
2011-01-10 16:43 ` [PATCH 01/12] xenpaging: remove domain_id and mfn from struct xenpaging_victim Olaf Hering
2011-01-10 16:43 ` [PATCH 02/12] xenpaging: specify policy mru_size at runtime Olaf Hering
2011-01-10 16:43 ` [PATCH 03/12] xenpaging: mkdir /var/lib/xen/xenpaging during make install Olaf Hering
2011-01-10 16:43 ` [PATCH 04/12] xenpaging: print page-in/page-out progress Olaf Hering
2011-01-10 16:43 ` [PATCH 05/12] xenpaging: make three functions static Olaf Hering
2011-01-11 18:36 ` Ian Jackson
2011-01-10 16:43 ` [PATCH 06/12] xenpaging: update machine_to_phys_mapping[] during page deallocation Olaf Hering
2011-01-11 10:37 ` Keir Fraser
2011-01-11 11:00 ` Olaf Hering
2011-01-11 11:29 ` Keir Fraser
2011-01-10 16:43 ` [PATCH 07/12] xenpaging: update machine_to_phys_mapping[] during page-in Olaf Hering
2011-01-10 16:43 ` Olaf Hering [this message]
2011-01-14 16:53 ` [PATCH 08/12] xenpaging: drop paged pages in guest_remove_page Olaf Hering
2011-01-10 16:43 ` [PATCH 09/12] xenpaging: prevent page-out of gfn 0x80 Olaf Hering
2011-01-10 16:43 ` [PATCH 10/12] xenpaging: handle HVMCOPY_gfn_paged_out in copy_from/to_user Olaf Hering
2011-01-10 16:43 ` [PATCH 11/12] xenpaging: start xenpaging via config option Olaf Hering
2011-01-10 16:43 ` [PATCH 12/12] xenpaging: document missing live migration Olaf Hering
2011-01-11 17:20 ` [PATCH 00/12] xenpaging changes for xen-unstable Ian Jackson
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=20110110164348.394538387@aepfle.de \
--to=olaf@aepfle.de \
--cc=xen-devel@lists.xensource.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.