| Message ID | 20150302203304.GA20513@dhcp22.suse.cz |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Michal Hocko <mhocko@suse.cz> Date: Mon, 2 Mar 2015 21:33:04 +0100 > On Mon 02-03-15 15:04:05, David S. Miller wrote: >> From: Michal Hocko <mhocko@suse.cz> >> Date: Mon, 2 Mar 2015 14:54:42 +0100 >> >> > mdesc_kmalloc is currently requiring __GFP_NOFAIL allocation although it >> > seems that the allocation failure is handled by all callers (via >> > mdesc_alloc). __GFP_NOFAIL is a strong liability for the memory >> > allocator and so the users are discouraged to use the flag unless the >> > allocation failure is really a nogo. Drop the flag here as this doesn't >> > seem to be the case. >> > >> > Signed-off-by: Michal Hocko <mhocko@suse.cz> >> >> It is a serious failure. >> >> If we miss an MDESC update due to this allocation failure, the update >> is not an event which gets retransmitted so we will lose the updated >> machine description forever. >> >> We really need this allocation to succeed. > > OK, thanks for the clarification. This wasn't clear from the commit > which has introduced this code. I will drop this patch. Would you > accept something like the following instead? Sure. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c index 99632a87e697..26c80e18d7b1 100644 --- a/arch/sparc/kernel/mdesc.c +++ b/arch/sparc/kernel/mdesc.c @@ -130,26 +130,26 @@ static struct mdesc_mem_ops memblock_mdesc_ops = { static struct mdesc_handle *mdesc_kmalloc(unsigned int mdesc_size) { unsigned int handle_size; + struct mdesc_handle *hp; + unsigned long addr; void *base; handle_size = (sizeof(struct mdesc_handle) - sizeof(struct mdesc_hdr) + mdesc_size); + /* + * Allocation has to succeed because mdesc update would be missed + * and such events are not retransmitted. + */ base = kmalloc(handle_size + 15, GFP_KERNEL | __GFP_NOFAIL); - if (base) { - struct mdesc_handle *hp; - unsigned long addr; - - addr = (unsigned long)base; - addr = (addr + 15UL) & ~15UL; - hp = (struct mdesc_handle *) addr; + addr = (unsigned long)base; + addr = (addr + 15UL) & ~15UL; + hp = (struct mdesc_handle *) addr; - mdesc_handle_init(hp, handle_size, base); - return hp; - } + mdesc_handle_init(hp, handle_size, base); - return NULL; + return hp; } static void mdesc_kfree(struct mdesc_handle *hp)