From: Adam Litke <agl@us.ibm.com>
To: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Cc: 'David Gibson' <david@gibson.dropbear.id.au>,
wli@holomorphy.com, 'Andrew Morton' <akpm@osdl.org>,
linux-mm@kvack.org
Subject: Re: [patch] hugetlb strict commit accounting - v3
Date: Mon, 20 Mar 2006 09:35:21 -0600 [thread overview]
Message-ID: <1142868921.14508.3.camel@localhost.localdomain> (raw)
In-Reply-To: <200603100314.k2A3Evg28313@unix-os.sc.intel.com>
On Thu, 2006-03-09 at 19:14 -0800, Chen, Kenneth W wrote:
> @@ -98,6 +98,12 @@ struct page *alloc_huge_page(struct vm_a
> int i;
>
> spin_lock(&hugetlb_lock);
> + if (vma->vm_flags & VM_MAYSHARE)
> + resv_huge_pages--;
> + else if (free_huge_pages <= resv_huge_pages) {
> + spin_unlock(&hugetlb_lock);
> + return NULL;
> + }
> page = dequeue_huge_page(vma, addr);
> if (!page) {
> spin_unlock(&hugetlb_lock);
Unfortunately this will break down when two or more threads race to
allocate the same page. You end up with a double-decrement of
resv_huge_pages even though only one thread will win the race.
--
Adam Litke - (agl at us.ibm.com)
IBM Linux Technology Center
--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2006-03-20 15:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-10 3:14 Chen, Kenneth W
2006-03-10 4:37 ` 'David Gibson'
2006-03-10 4:46 ` Andrew Morton
2006-03-10 4:50 ` 'David Gibson'
2006-03-10 5:39 ` Andrew Morton
2006-03-10 5:48 ` Andrew Morton
2006-03-20 15:35 ` Adam Litke [this message]
2006-03-20 18:48 Chen, Kenneth W
2006-03-20 20:21 ` Adam Litke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1142868921.14508.3.camel@localhost.localdomain \
--to=agl@us.ibm.com \
--cc=akpm@osdl.org \
--cc=david@gibson.dropbear.id.au \
--cc=kenneth.w.chen@intel.com \
--cc=linux-mm@kvack.org \
--cc=wli@holomorphy.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox