From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: [PATCH 10/10] mm: add preempt points into __purge_vmap_area_lazy Date: Fri, 18 Nov 2016 14:03:56 +0100 Message-ID: <1479474236-4139-11-git-send-email-hch@lst.de> References: <1479474236-4139-1-git-send-email-hch@lst.de> Cc: aryabinin@virtuozzo.com, joelaf@google.com, jszhang@marvell.com, chris@chris-wilson.co.uk, joaodias@google.com, linux-mm@kvack.org, linux-rt-users@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org To: akpm@linux-foundation.org Return-path: In-Reply-To: <1479474236-4139-1-git-send-email-hch@lst.de> Sender: owner-linux-mm@kvack.org List-Id: linux-rt-users.vger.kernel.org From: Joel Fernandes Use cond_resched_lock to avoid holding the vmap_area_lock for a potentially long time and thus creating bad latencies for various workloads. Signed-off-by: Joel Fernandes [hch: split from a larger patch by Joel, wrote the crappy changelog] Signed-off-by: Christoph Hellwig Tested-by: Jisheng Zhang --- mm/vmalloc.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index dccf242..976db21 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -628,7 +628,7 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) struct llist_node *valist; struct vmap_area *va; struct vmap_area *n_va; - int nr = 0; + bool do_free = false; lockdep_assert_held(&vmap_purge_lock); @@ -638,18 +638,22 @@ static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) start = va->va_start; if (va->va_end > end) end = va->va_end; - nr += (va->va_end - va->va_start) >> PAGE_SHIFT; + do_free = true; } - if (!nr) + if (!do_free) return false; - atomic_sub(nr, &vmap_lazy_nr); flush_tlb_kernel_range(start, end); spin_lock(&vmap_area_lock); - llist_for_each_entry_safe(va, n_va, valist, purge_list) + llist_for_each_entry_safe(va, n_va, valist, purge_list) { + int nr = (va->va_end - va->va_start) >> PAGE_SHIFT; + __free_vmap_area(va); + atomic_sub(nr, &vmap_lazy_nr); + cond_resched_lock(&vmap_area_lock); + } spin_unlock(&vmap_area_lock); return true; } -- 2.1.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org