From a144ff09bc52ef3f3684ed23eadc9c7c0e57b3aa Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 17 Jun 2008 10:47:08 +0200 Subject: xen: Avoid allocations causing swap activity on the resume path Avoid allocations causing swap activity on the resume path by preventing the allocations from doing IO and allowing them to access the emergency pools. These paths are used when a frontend device is trying to connect to its backend driver over Xenbus. These reconnections are triggered on demand by IO, so by definition there is already IO underway, and further IO would naturally deadlock. On resume, this path is triggered when the running system tries to continue using its devices. If it cannot then the resume will fail; to try to avoid this we let it dip into the emergency pools. [ linux-2.6.18-xen changesets e8b49cfbdac, fdb998e79aba ] Signed-off-by: Ian Campbell Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Jens Axboe --- drivers/xen/xenbus/xenbus_client.c | 2 +- drivers/xen/xenbus/xenbus_xs.c | 10 +++++----- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index 0f86b0f..9678b3e 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -117,7 +117,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, char *path; va_start(ap, pathfmt); - path = kvasprintf(GFP_KERNEL, pathfmt, ap); + path = kvasprintf(GFP_NOIO | __GFP_HIGH, pathfmt, ap); va_end(ap); if (!path) { diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 227d53b1..7f2f91c 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -283,9 +283,9 @@ static char *join(const char *dir, const char *name) char *buffer; if (strlen(name) == 0) - buffer = kasprintf(GFP_KERNEL, "%s", dir); + buffer = kasprintf(GFP_NOIO | __GFP_HIGH, "%s", dir); else - buffer = kasprintf(GFP_KERNEL, "%s/%s", dir, name); + buffer = kasprintf(GFP_NOIO | __GFP_HIGH, "%s/%s", dir, name); return (!buffer) ? ERR_PTR(-ENOMEM) : buffer; } @@ -297,7 +297,7 @@ static char **split(char *strings, unsigned int len, unsigned int *num) *num = count_strings(strings, len); /* Transfer to one big alloc for easy freeing. */ - ret = kmalloc(*num * sizeof(char *) + len, GFP_KERNEL); + ret = kmalloc(*num * sizeof(char *) + len, GFP_NOIO | __GFP_HIGH); if (!ret) { kfree(strings); return ERR_PTR(-ENOMEM); @@ -751,7 +751,7 @@ static int process_msg(void) } - msg = kmalloc(sizeof(*msg), GFP_KERNEL); + msg = kmalloc(sizeof(*msg), GFP_NOIO | __GFP_HIGH); if (msg == NULL) { err = -ENOMEM; goto out; @@ -763,7 +763,7 @@ static int process_msg(void) goto out; } - body = kmalloc(msg->hdr.len + 1, GFP_KERNEL); + body = kmalloc(msg->hdr.len + 1, GFP_NOIO | __GFP_HIGH); if (body == NULL) { kfree(msg); err = -ENOMEM; -- cgit v1.1