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Viewing changes to src/lib/lwan-readahead.c

  • Committer: Leandro Pereira
  • Date: 2019-02-19 03:26:42 UTC
  • Revision ID: git-v1:e188156997a13a08d6703f77039893cc27e070c7
Don't bother queueing readahead()/madvise() less than a page

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Lines of Context:
src/lib/lwan-readahead.c
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static int readahead_pipe_fd[2] = {-1, -1};
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static pthread_t readahead_self;
 
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static long page_size = 4096;
 
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#if _SC_PAGESIZE > 0
 
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__attribute__((constructor)) static void get_page_size(void)
 
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{
 
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    long ps = sysconf(_SC_PAGESIZE);
 
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    if (ps >= 0)
 
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        page_size = ps;
 
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}
 
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#endif
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void lwan_readahead_shutdown(void)
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{
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void lwan_readahead_queue(int fd, off_t off, size_t size)
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{
 
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    if (size < (size_t)page_size)
 
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        return;
 
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    struct lwan_readahead_cmd cmd = {
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        .readahead = {.size = size, .fd = fd, .off = off},
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        .cmd = READAHEAD,
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void lwan_madvise_queue(void *addr, size_t length)
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{
 
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    if (length < (size_t)page_size)
 
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        return;
 
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    struct lwan_readahead_cmd cmd = {
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        .madvise = {.addr = addr, .length = length},
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        .cmd = MADVISE,
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    };
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    /* Readahead is just a hint.  Failing to write is not an error. */
 
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    /* Madvise is just a hint.  Failing to write is not an error. */
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    write(readahead_pipe_fd[1], &cmd, sizeof(cmd));
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}
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