From: Vlastimil Babka <vbabka@suse.cz>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] mm/thp: Allocate transparent hugepages on local node
Date: Wed, 21 Jan 2015 12:28:05 +0100 [thread overview]
Message-ID: <54BF8D45.7030205@suse.cz> (raw)
In-Reply-To: <54BE1B00.3090102@suse.cz>
On 01/20/2015 10:08 AM, Vlastimil Babka wrote:
> On 01/20/2015 06:52 AM, Aneesh Kumar K.V wrote:
>> Vlastimil Babka <vbabka@suse.cz> writes:
>>
>> is that check correct ? ie,
>>
>> if ((gfp & GFP_TRANSHUGE) == GFP_TRANSHUGE)
>>
>> may not always indicate transparent hugepage if defrag = 0 . With defrag
>> cleared, we remove __GFP_WAIT from GFP_TRANSHUGE.
>
> Yep, that looks wrong. Sigh. I guess we can't spare an extra GFP flag to
> indicate TRANSHUGE?
I wanted to fix this in __alloc_pages_slowpath(), but actually there's no issue
(other than being quite subtle) - if defrag == 0 and thus we don't have
__GFP_WAIT, we reach "if (!wait) goto nopage;" and bail out before reaching the
checks for GFP_TRANSHUGE.
>> static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
>> {
>> return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
>> }
>>
>> -aneesh
>>
>> --
>> 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>
>>
>
> --
> 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>
>
--
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>
WARNING: multiple messages have this Message-ID (diff)
From: Vlastimil Babka <vbabka@suse.cz>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>,
David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH V3] mm/thp: Allocate transparent hugepages on local node
Date: Wed, 21 Jan 2015 12:28:05 +0100 [thread overview]
Message-ID: <54BF8D45.7030205@suse.cz> (raw)
In-Reply-To: <54BE1B00.3090102@suse.cz>
On 01/20/2015 10:08 AM, Vlastimil Babka wrote:
> On 01/20/2015 06:52 AM, Aneesh Kumar K.V wrote:
>> Vlastimil Babka <vbabka@suse.cz> writes:
>>
>> is that check correct ? ie,
>>
>> if ((gfp & GFP_TRANSHUGE) == GFP_TRANSHUGE)
>>
>> may not always indicate transparent hugepage if defrag = 0 . With defrag
>> cleared, we remove __GFP_WAIT from GFP_TRANSHUGE.
>
> Yep, that looks wrong. Sigh. I guess we can't spare an extra GFP flag to
> indicate TRANSHUGE?
I wanted to fix this in __alloc_pages_slowpath(), but actually there's no issue
(other than being quite subtle) - if defrag == 0 and thus we don't have
__GFP_WAIT, we reach "if (!wait) goto nopage;" and bail out before reaching the
checks for GFP_TRANSHUGE.
>> static inline gfp_t alloc_hugepage_gfpmask(int defrag, gfp_t extra_gfp)
>> {
>> return (GFP_TRANSHUGE & ~(defrag ? 0 : __GFP_WAIT)) | extra_gfp;
>> }
>>
>> -aneesh
>>
>> --
>> 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>
>>
>
> --
> 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:[~2015-01-21 11:28 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-16 7:26 [PATCH V3] mm/thp: Allocate transparent hugepages on local node Aneesh Kumar K.V
2015-01-16 7:26 ` Aneesh Kumar K.V
2015-01-16 12:27 ` Kirill A. Shutemov
2015-01-16 12:27 ` Kirill A. Shutemov
2015-01-16 20:01 ` Vlastimil Babka
2015-01-16 20:01 ` Vlastimil Babka
2015-01-17 0:02 ` Andrew Morton
2015-01-17 0:02 ` Andrew Morton
2015-01-17 7:15 ` Davidlohr Bueso
2015-01-17 7:15 ` Davidlohr Bueso
2015-01-18 15:50 ` Aneesh Kumar K.V
2015-01-18 15:50 ` Aneesh Kumar K.V
2015-01-18 15:48 ` Aneesh Kumar K.V
2015-01-18 15:48 ` Aneesh Kumar K.V
2015-01-19 16:27 ` Vlastimil Babka
2015-01-19 16:27 ` Vlastimil Babka
2015-01-20 5:52 ` Aneesh Kumar K.V
2015-01-20 5:52 ` Aneesh Kumar K.V
2015-01-20 9:08 ` Vlastimil Babka
2015-01-20 9:08 ` Vlastimil Babka
2015-01-21 11:28 ` Vlastimil Babka [this message]
2015-01-21 11:28 ` Vlastimil Babka
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=54BF8D45.7030205@suse.cz \
--to=vbabka@suse.cz \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.vnet.ibm.com \
--cc=kirill@shutemov.name \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=rientjes@google.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.