Messages in this thread | | | Subject | Re: [PATCH 1/2] Move kfree_call_rcu() to slab_common.c | From | Rao Shoaib <> | Date | Thu, 4 Jan 2018 13:27:49 -0800 |
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On 01/04/2018 12:35 PM, Rao Shoaib wrote: > Hi Boqun, > > Thanks a lot for all your guidance and for catching the cut and paster > error. Please see inline. > > > On 01/03/2018 05:38 PM, Boqun Feng wrote: >> >> But you introduced a bug here, you should use rcu_state_p instead of >> &rcu_sched_state as the third parameter for __call_rcu(). >> >> Please re-read: >> >> https://marc.info/?l=linux-mm&m=151390529209639 >> >> , and there are other comments, which you still haven't resolved in this >> version. You may want to write a better commit log to explain the >> reasons of each modifcation and fix bugs or typos in your previous >> version. That's how review process works ;-) >> >> Regards, >> Boqun >> > This is definitely a serious error. Thanks for catching this. > > As far as your previous comments are concerned, only the following one > has not been addressed. Can you please elaborate as I do not > understand the comment. The code was expanded because the new macro > expansion check fails. Based on Matthew Wilcox's comment I have > reverted rcu_head_name back to rcu_head. It turns out I did not remember the real reason for the change. With the macro rewritten, using rcu_head as a macro argument does not work because it conflicts with the name of the type 'struct rcu_head' used in the macro. I have renamed the macro argument to rcu_name.
Shoaib > >> +#define kfree_rcu(ptr, rcu_head_name) \ >> + do { \ >> + typeof(ptr) __ptr = ptr; \ >> + unsigned long __off = offsetof(typeof(*(__ptr)), \ >> + rcu_head_name); \ >> + struct rcu_head *__rptr = (void *)__ptr + __off; \ >> + __kfree_rcu(__rptr, __off); \ >> + } while (0) > > why do you want to open code this? > > Does the following text for the commit log looks better. > > kfree_rcu() should use the new kfree_bulk() interface for freeing rcu > structures > > The newly implemented kfree_bulk() interfaces are more efficient, > using the interfaces for freeing rcu structures has shown performance > improvements in synthetic benchmarks that allocate and free rcu > structures at a high rate. > > Shoaib > > -- > 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>
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