Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965086AbcJVPRw (ORCPT ); Sat, 22 Oct 2016 11:17:52 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:38176 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965024AbcJVPRt (ORCPT ); Sat, 22 Oct 2016 11:17:49 -0400 From: Christoph Hellwig To: akpm@linux-foundation.org Cc: joelaf@google.com, jszhang@marvell.com, chris@chris-wilson.co.uk, joaodias@google.com, linux-mm@kvack.org, linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 7/7] mm: add preempt points into __purge_vmap_area_lazy Date: Sat, 22 Oct 2016 17:17:20 +0200 Message-Id: <1477149440-12478-8-git-send-email-hch@lst.de> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1477149440-12478-1-git-send-email-hch@lst.de> References: <1477149440-12478-1-git-send-email-hch@lst.de> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1583 Lines: 56 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 23d6797..6c8b921 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