From 9be4d4575906af9698de660e477f949a076c87e1 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 31 Aug 2010 15:01:16 -0700 Subject: xen: add extra pages to balloon Add extra pages in the pseudo-physical address space to the balloon so we can extend into them later. Signed-off-by: Jeremy Fitzhardinge --- drivers/xen/balloon.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 500290b150bb..df26ee9caa68 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -119,7 +119,7 @@ static void scrub_page(struct page *page) } /* balloon_append: add the given page to the balloon. */ -static void balloon_append(struct page *page) +static void __balloon_append(struct page *page) { /* Lowmem is re-populated first, so highmem pages go at list tail. */ if (PageHighMem(page)) { @@ -130,7 +130,11 @@ static void balloon_append(struct page *page) list_add(&page->lru, &ballooned_pages); balloon_stats.balloon_low++; } +} +static void balloon_append(struct page *page) +{ + __balloon_append(page); totalram_pages--; } @@ -416,10 +420,13 @@ static int __init balloon_init(void) register_balloon(&balloon_sysdev); /* Initialise the balloon with excess memory space. */ - for (pfn = xen_start_info->nr_pages; pfn < max_pfn; pfn++) { + for (pfn = PFN_UP(xen_extra_mem_start); + pfn < PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size); + pfn++) { page = pfn_to_page(pfn); - if (!PageReserved(page)) - balloon_append(page); + /* totalram_pages doesn't include the boot-time + balloon extension, so don't subtract from it. */ + __balloon_append(page); } target_watch.callback = watch_target; -- cgit v1.2.3 From 2f70e0acd496398671606767122846278126a88b Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 2 Sep 2010 23:11:17 -0700 Subject: xen/balloon: the balloon_lock is useless The balloon_lock is useless, since it protects nothing against nothing. Signed-off-by: Jeremy Fitzhardinge --- drivers/xen/balloon.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index df26ee9caa68..77b5dc3597e3 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -195,7 +195,7 @@ static unsigned long current_target(void) static int increase_reservation(unsigned long nr_pages) { - unsigned long pfn, i, flags; + unsigned long pfn, i; struct page *page; long rc; struct xen_memory_reservation reservation = { @@ -207,8 +207,6 @@ static int increase_reservation(unsigned long nr_pages) if (nr_pages > ARRAY_SIZE(frame_list)) nr_pages = ARRAY_SIZE(frame_list); - spin_lock_irqsave(&xen_reservation_lock, flags); - page = balloon_first_page(); for (i = 0; i < nr_pages; i++) { BUG_ON(page == NULL); @@ -251,14 +249,12 @@ static int increase_reservation(unsigned long nr_pages) balloon_stats.current_pages += rc; out: - spin_unlock_irqrestore(&xen_reservation_lock, flags); - return rc < 0 ? rc : rc != nr_pages; } static int decrease_reservation(unsigned long nr_pages) { - unsigned long pfn, i, flags; + unsigned long pfn, i; struct page *page; int need_sleep = 0; int ret; @@ -296,8 +292,6 @@ static int decrease_reservation(unsigned long nr_pages) kmap_flush_unused(); flush_tlb_all(); - spin_lock_irqsave(&xen_reservation_lock, flags); - /* No more mappings: invalidate P2M and add to balloon. */ for (i = 0; i < nr_pages; i++) { pfn = mfn_to_pfn(frame_list[i]); @@ -312,8 +306,6 @@ static int decrease_reservation(unsigned long nr_pages) balloon_stats.current_pages -= nr_pages; - spin_unlock_irqrestore(&xen_reservation_lock, flags); - return need_sleep; } -- cgit v1.2.3 From 66946f676776a6ef333db1cf7453ecf8a66c90df Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 14 Sep 2010 10:32:32 -0700 Subject: xen/balloon: make sure we only include remaining extra ram If the user specifies mem= on the kernel command line, some or all of the extra memory E820 region may be clipped away, so make sure we don't try to add more extra memory than exists in E820. Signed-off-by: Jeremy Fitzhardinge --- drivers/xen/balloon.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 77b5dc3597e3..2b17ad5b4b32 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -391,7 +392,7 @@ static struct notifier_block xenstore_notifier; static int __init balloon_init(void) { - unsigned long pfn; + unsigned long pfn, extra_pfn_end; struct page *page; if (!xen_pv_domain()) @@ -412,8 +413,10 @@ static int __init balloon_init(void) register_balloon(&balloon_sysdev); /* Initialise the balloon with excess memory space. */ + extra_pfn_end = min(e820_end_of_ram_pfn(), + (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size)); for (pfn = PFN_UP(xen_extra_mem_start); - pfn < PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size); + pfn < extra_pfn_end; pfn++) { page = pfn_to_page(pfn); /* totalram_pages doesn't include the boot-time -- cgit v1.2.3 From 2a4c92fa24e1853d0e21f9e6e45859b832240f94 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Thu, 2 Dec 2010 15:30:06 -0800 Subject: xen: prevent crashes with non-HIGHMEM 32-bit kernels with largeish memory If this is a non-HIGHMEM 32-bit kernel, then the page structures only go up to the limit of addressable memory, even if more memory is physically present. Don't try to add that extra memory to the balloon. Signed-off-by: Jeremy Fitzhardinge --- drivers/xen/balloon.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/xen/balloon.c') diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 2b17ad5b4b32..43f9f02c7db0 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -412,8 +412,16 @@ static int __init balloon_init(void) register_balloon(&balloon_sysdev); - /* Initialise the balloon with excess memory space. */ - extra_pfn_end = min(e820_end_of_ram_pfn(), + /* + * Initialise the balloon with excess memory space. We need + * to make sure we don't add memory which doesn't exist or + * logically exist. The E820 map can be trimmed to be smaller + * than the amount of physical memory due to the mem= command + * line parameter. And if this is a 32-bit non-HIGHMEM kernel + * on a system with memory which requires highmem to access, + * don't try to use it. + */ + extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()), (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size)); for (pfn = PFN_UP(xen_extra_mem_start); pfn < extra_pfn_end; -- cgit v1.2.3