linux-kernel - Re: [PATCH 2/2] cfq-iosched: get rid of the need for __GFP_FAIL in cfq_find_alloc

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 01 Jul 2009 17:28:29 +0800
From:	Shan Wei <shanwei@...fujitsu.com>
To:	Jens Axboe <jens.axboe@...cle.com>
CC:	linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
	Jeff Moyer <jmoyer@...hat.com>
Subject: Re: [PATCH 2/2] cfq-iosched: get rid of the need for __GFP_FAIL in
 cfq_find_alloc_queue()

Jens Axboe said:
> Setup an emergency fallback cfqq that we allocate at IO scheduler init
> time. If the slab allocation fails in cfq_find_alloc_queue(), we'll just
> punt IO to that cfqq instead. This ensures that cfq_find_alloc_queue()
> never fails without having to ensure free memory.
> 
> Signed-off-by: Jens Axboe <jens.axboe@...cle.com>
> ---
>  
> @@ -1740,11 +1745,8 @@ cfq_get_queue(struct cfq_data *cfqd, int is_sync, struct io_context *ioc,
>  		cfqq = *async_cfqq;
>  	}
>  
> -	if (!cfqq) {
> +	if (!cfqq)
>  		cfqq = cfq_find_alloc_queue(cfqd, is_sync, ioc, gfp_mask);
> -		if (!cfqq)
> -			return NULL;
> -	}

I jsut reviewed the code and found that the check of cfqq is also redundant
after doing cfq_get_queue() in cfq_set_request.

The patch is based on Linus's main tree. 

Signed-off-by: Shan Wei <shanwei@...fujitsu.com>
---
 block/cfq-iosched.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 833ec18..c373237 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2307,10 +2307,6 @@ cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
 	cfqq = cic_to_cfqq(cic, is_sync);
 	if (!cfqq) {
 		cfqq = cfq_get_queue(cfqd, is_sync, cic->ioc, gfp_mask);
-
-		if (!cfqq)
-			goto queue_fail;
-
 		cic_set_cfqq(cic, cfqq, is_sync);
 	}
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/