Messages in this thread | | | Subject | Re: [PATCH] RDMA/irdma: Improve the way 'cqp_request' structures are cleaned when they are recycled | From | Christophe JAILLET <> | Date | Tue, 20 Jul 2021 15:05:55 +0200 |
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Le 20/07/2021 à 14:23, Leon Romanovsky a écrit : > On Mon, Jul 19, 2021 at 07:02:15PM +0200, Christophe JAILLET wrote: >> A set of IRDMA_CQP_SW_SQSIZE_2048 (i.e. 2048) 'cqp_request' are >> pre-allocated and zeroed in 'irdma_create_cqp()' (hw.c). These >> structures are managed with the 'cqp->cqp_avail_reqs' list which keeps >> track of available entries. >> >> In 'irdma_free_cqp_request()' (utils.c), when an entry is recycled and goes >> back to the 'cqp_avail_reqs' list, some fields are reseted. >> >> However, one of these fields, 'compl_info', is initialized within >> 'irdma_alloc_and_get_cqp_request()'. >> >> Move the corresponding memset to 'irdma_free_cqp_request()' so that the >> clean-up is done in only one place. This makes the logic more easy to >> understand. > > I'm not so sure. The function irdma_alloc_and_get_cqp_request() returns > prepared cqp_request and all users expect that it will returned cleaned > one. The reliance on some other place to clear part of the structure is > prone to errors.
Ok, so maybe, moving: cqp_request->request_done = false; cqp_request->callback_fcn = NULL; cqp_request->waiting = false; from 'irdma_free_cqp_request()' to 'irdma_alloc_and_get_cqp_request()' to make explicit what is reseted makes more sense?
From my point of view, it is same same: all (re)initialization are done at 1 place only.
This would also avoid setting 'waiting' twice (once to false in 'irdma_free_cqp_request()' and one to 'wait' 'irdma_alloc_and_get_cqp_request()')
CJ > > Thanks > >> >> This also saves this memset in the case that the 'cqp_avail_reqs' list is >> empty and a new 'cqp_request' structure must be allocated. This memset is >> useless, because the structure is already kzalloc'ed. >> >> Signed-off-by: Christophe JAILLET <christophe.jaillet-39ZsbGIQGT5GWvitb5QawA@public.gmane.org> >> --- >> drivers/infiniband/hw/irdma/utils.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/infiniband/hw/irdma/utils.c b/drivers/infiniband/hw/irdma/utils.c >> index 5bbe44e54f9a..66711024d38b 100644 >> --- a/drivers/infiniband/hw/irdma/utils.c >> +++ b/drivers/infiniband/hw/irdma/utils.c >> @@ -445,7 +445,6 @@ struct irdma_cqp_request *irdma_alloc_and_get_cqp_request(struct irdma_cqp *cqp, >> >> cqp_request->waiting = wait; >> refcount_set(&cqp_request->refcnt, 1); >> - memset(&cqp_request->compl_info, 0, sizeof(cqp_request->compl_info)); >> >> return cqp_request; >> } >> @@ -475,6 +474,7 @@ void irdma_free_cqp_request(struct irdma_cqp *cqp, >> cqp_request->request_done = false; >> cqp_request->callback_fcn = NULL; >> cqp_request->waiting = false; >> + memset(&cqp_request->compl_info, 0, sizeof(cqp_request->compl_info)); >> >> spin_lock_irqsave(&cqp->req_lock, flags); >> list_add_tail(&cqp_request->list, &cqp->cqp_avail_reqs); >> -- >> 2.30.2 >> >
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