From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 659486B0092 for ; Thu, 14 Jan 2010 01:48:55 -0500 (EST) Received: from m3.gw.fujitsu.co.jp ([10.0.50.73]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o0E6mpim008580 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Thu, 14 Jan 2010 15:48:52 +0900 Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 9D48D45DE51 for ; Thu, 14 Jan 2010 15:48:51 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 7D26545DE4F for ; Thu, 14 Jan 2010 15:48:51 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 62A5FE38002 for ; Thu, 14 Jan 2010 15:48:51 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.249.87.105]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 0F68BE08004 for ; Thu, 14 Jan 2010 15:48:51 +0900 (JST) From: KOSAKI Motohiro Subject: [PATCH] mm: Fix mbind vma merge problem Message-Id: <20100114154720.6732.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Thu, 14 Jan 2010 15:48:50 +0900 (JST) Sender: owner-linux-mm@kvack.org To: LKML , linux-mm , Andrew Morton , Christoph Lameter Cc: kosaki.motohiro@jp.fujitsu.com List-ID: Strangely, current mbind() doesn't merge vma with neighbor vma although it's possible. Unfortunately, many vma can reduce performance... This patch fixes it. reproduced program ---------------------------------------------------------------- #include #include #include #include #include #include #include static unsigned long pagesize; int main(int argc, char** argv) { void* addr; int ch; int node; struct bitmask *nmask = numa_allocate_nodemask(); int err; int node_set = 0; char buf[128]; while ((ch = getopt(argc, argv, "n:")) != -1){ switch (ch){ case 'n': node = strtol(optarg, NULL, 0); numa_bitmask_setbit(nmask, node); node_set = 1; break; default: ; } } argc -= optind; argv += optind; if (!node_set) numa_bitmask_setbit(nmask, 0); pagesize = getpagesize(); addr = mmap(NULL, pagesize*3, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, 0, 0); if (addr == MAP_FAILED) perror("mmap "), exit(1); fprintf(stderr, "pid = %d \n" "addr = %p\n", getpid(), addr); /* make page populate */ memset(addr, 0, pagesize*3); /* first mbind */ err = mbind(addr+pagesize, pagesize, MPOL_BIND, nmask->maskp, nmask->size, MPOL_MF_MOVE_ALL); if (err) error("mbind1 "); /* second mbind */ err = mbind(addr, pagesize*3, MPOL_DEFAULT, NULL, 0, 0); if (err) error("mbind2 "); sprintf(buf, "cat /proc/%d/maps", getpid()); system(buf); return 0; } ---------------------------------------------------------------- result without this patch addr = 0x7fe26ef09000 [snip] 7fe26ef09000-7fe26ef0a000 rw-p 00000000 00:00 0 7fe26ef0a000-7fe26ef0b000 rw-p 00000000 00:00 0 7fe26ef0b000-7fe26ef0c000 rw-p 00000000 00:00 0 7fe26ef0c000-7fe26ef0d000 rw-p 00000000 00:00 0 => 0x7fe26ef09000-0x7fe26ef0c000 have three vmas. result with this patch addr = 0x7fc9ebc76000 [snip] 7fc9ebc76000-7fc9ebc7a000 rw-p 00000000 00:00 0 7fffbe690000-7fffbe6a5000 rw-p 00000000 00:00 0 [stack] => 0x7fc9ebc76000-0x7fc9ebc7a000 have only one vma. Signed-off-by: KOSAKI Motohiro --- mm/mempolicy.c | 51 ++++++++++++++++++++++++++++++++++++++------------- 1 files changed, 38 insertions(+), 13 deletions(-) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 290fb5b..9751f3f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -563,24 +563,49 @@ static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new) } /* Step 2: apply policy to a range and do splits. */ -static int mbind_range(struct vm_area_struct *vma, unsigned long start, - unsigned long end, struct mempolicy *new) +static int mbind_range(struct mm_struct *mm, unsigned long start, + unsigned long end, struct mempolicy *new_pol) { struct vm_area_struct *next; - int err; + struct vm_area_struct *prev; + struct vm_area_struct *vma; + int err = 0; + unsigned long vmstart; + unsigned long vmend; - err = 0; - for (; vma && vma->vm_start < end; vma = next) { + vma = find_vma_prev(mm, start, &prev); + if (!vma || vma->vm_start > start) + return -EFAULT; + + for (; vma && vma->vm_start < end; prev = vma, vma = next) { next = vma->vm_next; - if (vma->vm_start < start) - err = split_vma(vma->vm_mm, vma, start, 1); - if (!err && vma->vm_end > end) - err = split_vma(vma->vm_mm, vma, end, 0); - if (!err) - err = policy_vma(vma, new); + vmstart = max(start, vma->vm_start); + vmend = min(end, vma->vm_end); + + prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags, + vma->anon_vma, vma->vm_file, vma->vm_pgoff, + new_pol); + if (prev) { + vma = prev; + next = vma->vm_next; + continue; + } + if (vma->vm_start != vmstart) { + err = split_vma(vma->vm_mm, vma, vmstart, 1); + if (err) + goto out; + } + if (vma->vm_end != vmend) { + err = split_vma(vma->vm_mm, vma, vmend, 0); + if (err) + goto out; + } + err = policy_vma(vma, new_pol); if (err) - break; + goto out; } + + out: return err; } @@ -1047,7 +1072,7 @@ static long do_mbind(unsigned long start, unsigned long len, if (!IS_ERR(vma)) { int nr_failed = 0; - err = mbind_range(vma, start, end, new); + err = mbind_range(mm, start, end, new); if (!list_empty(&pagelist)) nr_failed = migrate_pages(&pagelist, new_vma_page, -- 1.6.5.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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