diff mbox series

[RFC,06/27] vhost: don't dump unneeded pages with IOTLB

Message ID 20230331154259.1447831-7-maxime.coquelin@redhat.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series Add VDUSE support to Vhost library |

Commit Message

Maxime Coquelin March 31, 2023, 3:42 p.m. UTC 
  On IOTLB entry removal, previous fixes took care of not
marking pages shared with other IOTLB entries as DONTDUMP.

However, if an IOTLB entry is spanned on multiple pages,
the other pages were kept as DODUMP while they might not
have been shared with other entries, increasing needlessly
the coredump size.

This patch addresses this issue by excluding only the
shared pages from madvise's DONTDUMP.

Fixes: dea092d0addb ("vhost: fix madvise arguments alignment")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/iotlb.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

Comments

Mike Pattrick April 20, 2023, 5:11 p.m. UTC | #1 
On Fri, Mar 31, 2023 at 11:43 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> On IOTLB entry removal, previous fixes took care of not
> marking pages shared with other IOTLB entries as DONTDUMP.
>
> However, if an IOTLB entry is spanned on multiple pages,
> the other pages were kept as DODUMP while they might not
> have been shared with other entries, increasing needlessly
> the coredump size.
>
> This patch addresses this issue by excluding only the
> shared pages from madvise's DONTDUMP.
>
> Fixes: dea092d0addb ("vhost: fix madvise arguments alignment")
> Cc: stable@dpdk.org
>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Looks good to me.

Acked-by: Mike Pattrick <mkp@redhat.com>
Chenbo Xia April 24, 2023, 3 a.m. UTC | #2 
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Friday, March 31, 2023 11:43 PM
> To: dev@dpdk.org; david.marchand@redhat.com; Xia, Chenbo
> <chenbo.xia@intel.com>; mkp@redhat.com; fbl@redhat.com;
> jasowang@redhat.com; Liang, Cunming <cunming.liang@intel.com>; Xie, Yongji
> <xieyongji@bytedance.com>; echaudro@redhat.com; eperezma@redhat.com;
> amorenoz@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; stable@dpdk.org
> Subject: [RFC 06/27] vhost: don't dump unneeded pages with IOTLB
> 
> On IOTLB entry removal, previous fixes took care of not
> marking pages shared with other IOTLB entries as DONTDUMP.
> 
> However, if an IOTLB entry is spanned on multiple pages,
> the other pages were kept as DODUMP while they might not
> have been shared with other entries, increasing needlessly
> the coredump size.
> 
> This patch addresses this issue by excluding only the
> shared pages from madvise's DONTDUMP.
> 
> Fixes: dea092d0addb ("vhost: fix madvise arguments alignment")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/iotlb.c | 21 ++++++++++++++-------
>  1 file changed, 14 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/vhost/iotlb.c b/lib/vhost/iotlb.c
> index d919f74704..f598c0a8c4 100644
> --- a/lib/vhost/iotlb.c
> +++ b/lib/vhost/iotlb.c
> @@ -54,16 +54,23 @@ static void
>  vhost_user_iotlb_clear_dump(struct virtio_net *dev, struct
> vhost_iotlb_entry *node,
>  		struct vhost_iotlb_entry *prev, struct vhost_iotlb_entry *next)
>  {
> -	uint64_t align;
> +	uint64_t align, start, end;
> +
> +	start = node->uaddr;
> +	end = node->uaddr + node->size;
> 
>  	align = hua_to_alignment(dev->mem, (void *)(uintptr_t)node->uaddr);
> 
> -	/* Don't disable coredump if the previous node is in the same page
> */
> -	if (!vhost_user_iotlb_share_page(prev, node, align)) {
> -		/* Don't disable coredump if the next node is in the same page
> */
> -		if (!vhost_user_iotlb_share_page(node, next, align))
> -			mem_set_dump((void *)(uintptr_t)node->uaddr, node->size,
> false, align);
> -	}
> +	/* Skip first page if shared with previous entry. */
> +	if (vhost_user_iotlb_share_page(prev, node, align))
> +		start = RTE_ALIGN_CEIL(start, align);
> +
> +	/* Skip last page if shared with next entry. */
> +	if (vhost_user_iotlb_share_page(node, next, align))
> +		end = RTE_ALIGN_FLOOR(end, align);
> +
> +	if (end > start)
> +		mem_set_dump((void *)(uintptr_t)start, end - start, false,
> align);
>  }
> 
>  static struct vhost_iotlb_entry *
> --
> 2.39.2

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
diff mbox series

Patch

diff --git a/lib/vhost/iotlb.c b/lib/vhost/iotlb.c
index d919f74704..f598c0a8c4 100644
--- a/lib/vhost/iotlb.c
+++ b/lib/vhost/iotlb.c
@@ -54,16 +54,23 @@  static void
 vhost_user_iotlb_clear_dump(struct virtio_net *dev, struct vhost_iotlb_entry *node,
 		struct vhost_iotlb_entry *prev, struct vhost_iotlb_entry *next)
 {
-	uint64_t align;
+	uint64_t align, start, end;
+
+	start = node->uaddr;
+	end = node->uaddr + node->size;
 
 	align = hua_to_alignment(dev->mem, (void *)(uintptr_t)node->uaddr);
 
-	/* Don't disable coredump if the previous node is in the same page */
-	if (!vhost_user_iotlb_share_page(prev, node, align)) {
-		/* Don't disable coredump if the next node is in the same page */
-		if (!vhost_user_iotlb_share_page(node, next, align))
-			mem_set_dump((void *)(uintptr_t)node->uaddr, node->size, false, align);
-	}
+	/* Skip first page if shared with previous entry. */
+	if (vhost_user_iotlb_share_page(prev, node, align))
+		start = RTE_ALIGN_CEIL(start, align);
+
+	/* Skip last page if shared with next entry. */
+	if (vhost_user_iotlb_share_page(node, next, align))
+		end = RTE_ALIGN_FLOOR(end, align);
+
+	if (end > start)
+		mem_set_dump((void *)(uintptr_t)start, end - start, false, align);
 }
 
 static struct vhost_iotlb_entry *