ceph/src/os/bluestore/aio.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include <algorithm>
   5 #include "aio.h"
   6
   7 #if defined(HAVE_LIBAIO)
   8
   9
  10 int aio_queue_t::submit(aio_t &aio, int *retries)
  11 {
  12   // 2^16 * 125us = ~8 seconds, so max sleep is ~16 seconds
  13   int attempts = 16;
  14   int delay = 125;
  15   iocb *piocb = &aio.iocb;
  16   int r;
  17   while (true) {
  18     r = io_submit(ctx, 1, &piocb);
  19     if (r < 0) {
  20       if (r == -EAGAIN && attempts-- > 0) {
  21         usleep(delay);
  22         delay *= 2;
  23         (*retries)++;
  24         continue;
  25       }
  26     }
  27     assert(r == 1);
  28     break;
  29   }
  30   return r;
  31 }
  32
  33 int aio_queue_t::submit_batch(aio_iter begin, aio_iter end,
  34                               uint16_t aios_size, void *priv,
  35                               int *retries)
  36 {
  37   // 2^16 * 125us = ~8 seconds, so max sleep is ~16 seconds
  38   int attempts = 16;
  39   int delay = 125;
  40
  41   aio_iter cur = begin;
  42   struct iocb *piocb[aios_size];
  43   int left = 0;
  44   while (cur != end) {
  45     cur->priv = priv;
  46     *(piocb+left) = &cur->iocb;
  47     ++left;
  48     ++cur;
  49   }
  50   int done = 0;
  51   while (left > 0) {
  52     int r = io_submit(ctx, std::min(left, max_iodepth), piocb + done);
  53     if (r < 0) {
  54       if (r == -EAGAIN && attempts-- > 0) {
  55         usleep(delay);
  56         delay *= 2;
  57         (*retries)++;
  58         continue;
  59       }
  60       return r;
  61     }
  62     assert(r > 0);
  63     done += r;
  64     left -= r;
  65     attempts = 16;
  66     delay = 125;
  67   }
  68   return done;
  69 }
  70
  71 int aio_queue_t::get_next_completed(int timeout_ms, aio_t **paio, int max)
  72 {
  73   io_event event[max];
  74   struct timespec t = {
  75     timeout_ms / 1000,
  76     (timeout_ms % 1000) * 1000 * 1000
  77   };
  78
  79   int r = 0;
  80   do {
  81     r = io_getevents(ctx, 1, max, event, &t);
  82   } while (r == -EINTR);
  83
  84   for (int i=0; i<r; ++i) {
  85     paio[i] = (aio_t *)event[i].obj;
  86     paio[i]->rval = event[i].res;
  87   }
  88   return r;
  89 }
  90
  91 #endif